RFC 7937
Content Distribution Network Interconnection (CDNI) Logging Interface
🎀 RFC 7937: CDNI Logging Interface (Part 1 of 12) 🎀
okay bestie, grab your iced matcha because we are starting a brand new spec and it's giving big infrastructure energy 💅✨ This one is RFC 7937, and it's all about the Logging interface between two CDNs that are interconnected under the CDNI framework 🌐🦋
Quick glow-up of the title block so you know who's who 💖
- Number and title: RFC 7937, Content Distribution Network Interconnection (CDNI) Logging Interface 🌸
- Authors: F. Le Faucheur (Ed.), G. Bertrand (Ed.), I. Oprescu (Ed.), and R. Peterkofsky (Google Inc.) 🧚
- Category: Standards Track 👑
- Date: August 2016 📅
- Obsoletes and updates: the title block doesn't list anything here, so there's nothing to obsolete or update 🙈
- Stream and ISSN: IETF, ISSN 2070-1721 🍓
Abstract
okay so the whole point of this memo is to specify the Logging interface between a downstream CDN (dCDN) and an upstream CDN (uCDN) that are interconnected via the CDNI framework 🌈 It's split into two big chunks: first a reference model for CDNI logging, and then the actual CDNI Logging File format plus the protocol for swapping those files around 💜
Status of This Memo
This is an Internet Standards Track document. 💅
This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 7841. ✨
Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc7937. 🔥
Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the document authors. All rights reserved. 🎀
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. 🧾
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
1.2. Requirements Language . . . . . . . . . . . . . . . . . . 5
2. CDNI Logging Reference Model . . . . . . . . . . . . . . . . 5
2.1. CDNI Logging Interactions . . . . . . . . . . . . . . . . 5
2.2. Overall Logging Chain . . . . . . . . . . . . . . . . . . 9
2.2.1. Logging Generation and During-Generation Aggregation 10
2.2.2. Logging Collection . . . . . . . . . . . . . . . . . 11
2.2.3. Logging Filtering . . . . . . . . . . . . . . . . . . 11
2.2.4. Logging Rectification and Post-Generation Aggregation 12
2.2.5. Log-Consuming Applications . . . . . . . . . . . . . 13
2.2.5.1. Maintenance and Debugging . . . . . . . . . . . . 13
2.2.5.2. Accounting . . . . . . . . . . . . . . . . . . . 14
2.2.5.3. Analytics and Reporting . . . . . . . . . . . . . 14
2.2.5.4. Content Protection . . . . . . . . . . . . . . . 14
2.2.5.5. Notions Common to Multiple Log-Consuming
Applications . . . . . . . . . . . . . . . . . . 15
3. CDNI Logging File . . . . . . . . . . . . . . . . . . . . . . 17
3.1. Rules . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3.2. CDNI Logging File Structure . . . . . . . . . . . . . . . 18
3.3. CDNI Logging Directives . . . . . . . . . . . . . . . . . 21
3.4. CDNI Logging Records . . . . . . . . . . . . . . . . . . 26
3.4.1. HTTP Request Logging Record . . . . . . . . . . . . . 27
3.5. CDNI Logging File Extension . . . . . . . . . . . . . . . 38
3.6. CDNI Logging File Examples . . . . . . . . . . . . . . . 38
3.7. Cascaded CDNI Logging Files Example . . . . . . . . . . . 42
4. Protocol for Exchange of CDNI Logging File after Full
Collection . . . . . . . . . . . . . . . . . . . . . . . . . 44
4.1. CDNI Logging Feed . . . . . . . . . . . . . . . . . . . . 45
4.1.1. Atom Formatting . . . . . . . . . . . . . . . . . . . 45
4.1.2. Updates to Log Files and the Feed . . . . . . . . . . 46
4.1.3. Redundant Feeds . . . . . . . . . . . . . . . . . . . 47
4.1.4. Example CDNI Logging Feed . . . . . . . . . . . . . . 47
4.2. CDNI Logging File Pull . . . . . . . . . . . . . . . . . 49
5. Protocol for Exchange of CDNI Logging File During Collection 50
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 51
6.1. CDNI Logging Directive Names Registry . . . . . . . . . . 51
6.2. CDNI Logging File version Registry . . . . . . . . . . . 51
6.3. CDNI Logging record-types Registry . . . . . . . . . . . 52
6.4. CDNI Logging Field Names Registry . . . . . . . . . . . . 53
6.5. CDNI Logging Payload Type . . . . . . . . . . . . . . . . 55
7. Security Considerations . . . . . . . . . . . . . . . . . . . 55
7.1. Authentication, Authorization, Confidentiality, and
Integrity Protection . . . . . . . . . . . . . . . . . . 55
7.2. Denial of Service . . . . . . . . . . . . . . . . . . . . 56
7.3. Privacy . . . . . . . . . . . . . . . . . . . . . . . . . 57
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 58
8.1. Normative References . . . . . . . . . . . . . . . . . . 58
8.2. Informative References . . . . . . . . . . . . . . . . . 61
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 63
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 631. Introduction ✨
okay so this memo specifies the CDNI Logging interface between a downstream CDN (dCDN) and an upstream CDN (uCDN) 🦋 First it describes a reference model for CDNI logging, and then it specifies the CDNI Logging File format and the actual protocol for exchanging CDNI Logging Files 💖
Before you dive in, you should be familiar with these docs:
- CDNI problem statement [RFC6707] and framework [RFC7336], which identify a Logging interface 🌸
- Section 8 of [RFC7337], which specifies a set of requirements for Logging 🧚
- [RFC6770], which outlines real world use cases for interconnecting CDNs. These use cases require the exchange of Logging information between the dCDN and the uCDN 👑
As stated in [RFC6707], "the CDNI Logging interface enables details of content distribution and delivery activities to be exchanged between interconnected CDNs." 🎀
The present document describes:
- The CDNI Logging reference model (Section 2) 🍓
- The CDNI Logging File format (Section 3) 💜
- The CDNI Logging File Exchange protocol (Section 4) 🌈
1.1. Terminology 📚
In this document, the first letter of each CDNI-specific term is capitalized. We adopt the terminology described in [RFC6707] and [RFC7336], and extend it with the additional terms defined below. 💅
Intra-CDN Logging information: Logging information generated and collected within a CDN. The format of the Intra-CDN Logging information may be different from the format of the CDNI Logging information. 🦋
CDNI Logging information: Logging information exchanged across CDNs using the CDNI Logging interface. ✨
Logging information: Logging information generated and collected within a CDN or obtained from another CDN using the CDNI Logging interface. 💖
CDNI Logging Field: An atomic element of information that can be included in a CDNI Logging Record. The time an event/task started, the IP address of an end user to whom content was delivered, and the Uniform Resource Identifier (URI) of the content delivered, are examples of CDNI Logging fields. 🎀
CDNI Logging Record: An information record providing information about a specific event. This comprises a collection of CDNI Logging fields. 🌸
CDNI Logging File: A file containing CDNI Logging Records, as well as additional information facilitating the processing of the CDNI Logging Records. 🧚
CDN Reporting: The process of providing the relevant information that will be used to create a formatted content delivery report provided to the Content Service Provider (CSP) in deferred time. Such information typically includes aggregated data that can cover a large period of time (e.g., from hours to several months). Uses of reporting include the collection of charging data related to CDN services and the computation of Key Performance Indicators (KPIs). 📊
CDN Monitoring: The process of providing or displaying content delivery information in a timely fashion with respect to the corresponding deliveries. Monitoring typically includes visibility of the deliveries in progress for service operation purposes. It presents a view of the global health of the services as well as information on usage and performance, for network services supervision and operation management. In particular, monitoring data can be used to generate alarms. 🚨
1.2. Requirements Language 🫶
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119]. 🙈
These are the capital-letter requirement words, so they keep their exact force. Read them carefully, bestie 💀
2. CDNI Logging Reference Model 🌟
(Part 1 ends here. Part 2 picks up with Section 2 and the reference model. Stay tuned, we are just getting warmed up 🔥💜)
2.1. CDNI Logging Interactions ✨
okay so the CDNI logging reference model between a given uCDN and a given dCDN has these interactions 💅
- customization by the uCDN of the CDNI Logging information to be provided by the dCDN to the uCDN 🎀 (e.g., control of which CDNI Logging fields are to be communicated to the uCDN for a given task performed by the dCDN or control of which types of events are to be logged). The dCDN uses this customization info to decide what Logging info to hand back to the uCDN, but it may, or may not, use it to influence what CDN Logging info gets generated and collected inside the dCDN. For example, even if the uCDN asks for a restricted subset, the dCDN may choose to generate a broader set of Logging info. The mechanism for this uCDN customization is outside the scope of this document and is left for further study. Until that mechanism exists, the uCDN and dCDN are expected to agree off-line on the exact set of CDNI Logging info the dCDN provides, and to rely on management-plane actions to configure the CDNI Logging functions in the dCDN to generate that set and in the uCDN to expect it 🌸
- generation and collection by the dCDN of the intra-CDN Logging information related to the completion of any task the dCDN performs on behalf of the uCDN (e.g., delivery of the content to an end user) or related to events happening in the dCDN that matter to the uCDN (e.g., failures or unavailability in dCDN). This happens within the dCDN and does not directly involve CDNI interfaces 🧚
- communication by the dCDN to the uCDN of the Logging information collected by the dCDN that is relevant to the uCDN. This is supported by the CDNI Logging interface and is in the scope of the present document 🔥 For example, the uCDN may use this Logging information to charge the CSP, to perform analytics and monitoring for operational reasons, to provide analytics and monitoring views on its content delivery to the CSP, or to perform troubleshooting. This document exclusively specifies non-real-time exchange of Logging information. Closer to real-time exchange (say sub-minute or sub-second) is outside the scope of the present document and is left for further study. This document also exclusively specifies exchange of Logging information related to content delivery. Exchange of Logging information related to operational events (e.g., dCDN request routing function unavailable and content acquisition failure by dCDN) for audit or operational reactive adjustments by uCDN is outside the scope of the present document and is left for further study 🙈
- customization by the dCDN of the CDNI Logging information to be provided by the uCDN on behalf of the dCDN. The mechanism to support this dCDN customization is outside the scope of this document and is left for further study 🦋
- generation and collection by the uCDN of Intra-CDN Logging information related to the completion of any task the uCDN performs on behalf of the dCDN (e.g., serving of content by uCDN to dCDN for acquisition purposes by dCDN) or related to events happening in the uCDN that are relevant to the dCDN. This takes place within the uCDN and does not directly involve CDNI interfaces 💜
- communication by the uCDN to the dCDN of the Logging information collected by the uCDN that is relevant to the dCDN. For example, the dCDN might potentially benefit from this information for security auditing or content acquisition troubleshooting. This is outside the scope of this document and is left for further study 🌈
Figure 1 gives an example of CDNI Logging interactions (focusing only on the interactions that are in the scope of this document) in a particular scenario where four CDNs are involved in delivering content from a given CSP. The uCDN has a CDNI interconnection with dCDN-1 and dCDN-2. In turn, dCDN-2 has a CDNI interconnection with dCDN-3, where dCDN-2 is acting as an upstream CDN relative to dCDN-3. In this example, uCDN, dCDN-1, dCDN-2, and dCDN-3 all participate in the delivery of content for the CSP. The CDNI Logging interface enables the uCDN to obtain Logging information from all the dCDNs involved in the delivery. In the example, the uCDN uses the Logging information:
- to analyze the performance of the delivery performed by the dCDNs and to adjust its operations after the fact (e.g., request routing) as appropriate.
- to provide (non-real-time) reporting and monitoring information to the CSP.
For instance, the uCDN merges Logging information, extracts relevant KPIs, and presents a formatted report to the CSP, in addition to a bill for the content delivered by uCDN itself or by its dCDNs on the CSP's behalf 💅 The uCDN may also provide Logging information as raw log files to the CSP, so that the CSP can use its own logging analysis tools 🫶
+-----+
| CSP |
+-----+
^ Reporting and monitoring data
* Billing
,--*--.
Logging ,-' `-.
Data =>( uCDN )<= Logging
// `-. _,-' \\ Data
|| `-'-'-' ||
,-----. ,-----.
,-' `-. ,-' `-.
( dCDN-1 ) ( dCDN-2 )<== Logging
`-. ,-' `-. _,-' \\ Data
`--'--' `--'-' ||
,-----.
,' `-.
( dCDN-3 )
`. ,-'
`--'--'
===> CDNI Logging interface
***> outside the scope of CDNIFigure 1: Interactions in the CDNI Logging Reference Model
A downstream CDN relative to uCDN (e.g., dCDN-2) integrates the relevant Logging information obtained from its own downstream CDNs (i.e., dCDN-3) into the Logging information it provides to the uCDN. This way, the uCDN ultimately obtains all Logging information relevant to a CSP for which it acts as the authoritative CDN 🌟 Such aggregation is further discussed in Section 3.7.
Note that the format of Logging information a CDN provides over the CDNI interface might be different from the one that the CDN uses internally. In this case, the CDN needs to reformat the Logging information before it provides it to the other CDN over the CDNI Logging interface. Similarly, a CDN might reformat the Logging information it receives over the CDNI Logging interface before injecting it into its log-consuming applications or before providing some of it to the CSP. Such reformatting operations introduce latency in the logging distribution chain and add a processing burden. Therefore, there are benefits in specifying CDNI Logging formats that are suitable for use inside CDNs and that are also close to the intra-CDN Logging formats commonly used in CDNs today 🍓
2.2. Overall Logging Chain
This section discusses the overall logging chain within and across CDNs, to clarify how CDN Logging information is expected to fit into this overall chain 🧩 Figure 2 illustrates the overall logging chain within the dCDN, across CDNs using the CDNI Logging interface, and within the uCDN. The logging chain in the figure is obviously only an example and varies depending on the specific environment. For example, there may be more or fewer instances of each entity (e.g., there may be 4 log-consuming applications in a given CDN). As another example, there may be one instance of a Rectification process per log-consuming application instead of a shared one.
Log-Consuming Log-Consuming
App App
^ ^
| |
Rectification----------
^
|
Filtering
^
|
Collection
^ ^
| |
| Generation
|
| uCDN
CDNI Logging ---------------------------------------------------
exchange dCDN
^
| Log-Consuming Log-Consuming
| App App
| ^ ^
| | |
Rectification Rectification---------
^ ^
| |
Filtering
^
|
Collection
^ ^
| |
Generation GenerationFigure 2: CDNI Logging in the Overall Logging Chain
The following subsections describe each of the processes potentially involved in the logging chain of Figure 2 🦋
2.2.1. Logging Generation and During-Generation Aggregation
CDNs typically generate Logging information for all significant task completions, events, and failures. Logging information is typically generated by many devices in the CDN, including the surrogates, the request routing system, and the control system 🌸
The amount of Logging information generated can be huge 😭 Therefore, during contract negotiations, interconnected CDNs often agree on a retention duration for Logging information, and/or potentially on a maximum volume of Logging information that the dCDN ought to keep. If this volume is exceeded, the dCDN is expected to alert the uCDN, but it may not keep more Logging information for the considered time period. In addition, CDNs may aggregate Logging information and transmit only summaries for some categories of operations instead of the full Logging information. Note that such aggregation leads to an information loss, which may be problematic for some usages of the Logging information (e.g., debugging) 💀
[RFC6983] discusses logging for HTTP Adaptive Streaming (HAS). In accordance with the recommendations articulated there, it is expected that a surrogate will generate separate Logging information for delivery of each chunk of HAS content. This ensures that separate Logging information can then be provided to interconnected CDNs over the CDNI Logging interface. Still in line with the recommendations of [RFC6983], the Logging information for per-chunk delivery may include some information (a Content Collection IDentifier and a Session IDentifier) intended to facilitate subsequent post-generation aggregation of per-chunk logs into per-session logs. Note that a CDN may also elect to generate aggregate per-session logs when performing HAS delivery, but this needs to be in addition to, and not instead of, the per-chunk delivery logs. We note that aggregate per-session logs for HAS delivery are for further study and are outside the scope of this document 🎀
2.2.2. Logging Collection ✨
okay so Collection is the process that keeps grabbing Logging info from the log-generating entities inside a CDN, nonstop 💅
In a CDNI setup, it does that for its own CDN and also picks up Logging info from another CDN (or other CDNs) through the CDNI Logging interface. Figure 2 shows this: the uCDN's Collection process gathers info from its own log-generating entities AND the info coming from the dCDNs through the CDNI Logging interface. the main character moment is that it's all one collection pipeline 🎀
2.2.3. Logging Filtering 🦋
bestie, a CDN might only be allowed to show different subsets of everything it collected to different log-consuming apps. That's what the Filtering process is for 💖
Filtering can also pick out exactly the right subset to hand to a given interconnected CDN. For example, the dCDN's filter can make sure a uCDN only sees Logging info about tasks the dCDN ran on behalf of that uCDN, and it filters out everything about the dCDN's own deliveries for its own CSPs. Filtering can also filter or partially mask some fields, for example to protect end-users' privacy when sharing CDNI Logging info with another CDN. Before Logging info goes to other CDNs over the CDNI Logging interface, the downstream CDN has to be able to recognize which subset of Logging info belongs to each interconnected CDN 🔥
The CDN also filters out some internal stuff, like info about its internal alarms (security, failures, load, etc.) 🙈
In some use cases described in [RFC6770], the interconnected CDNs don't want to spill their internal topology tea. So the filter can also hide confidential data about the dCDN's topology (number of servers, location, etc.). Info about the requests each Surrogate served can be especially confidential, so the Logging info has to be protected so that stuff like Surrogate hostnames isn't revealed to the uCDN. In the "Inter-Affiliates Interconnection" use case, that info may be shared with the uCDN, because the dCDN and uCDN are run by entities in the same group 🫶
2.2.4. Logging Rectification and Post-Generation Aggregation 🌈
If Logging info is generated periodically, sessions that start in one Logging period and end in another have to be reported correctly 😭 If they get reported in the starting period, the Logging info for that period isn't ready until after the session ends, which slows down Logging info generation. The simple fix is to put the complete Logging Record for a session in the Logging Period where the session ends 💅
A Logging rectification/update mechanism could be useful for finding a good balance between how fast Logging info is generated and how accurate it is 🎀
When HAS is involved, some log-consuming apps can get a lot out of aggregate per-session logs. For analytics, per-session logs show session-related trends, which are way more meaningful for some kinds of analysis than chunk-related trends 📊
If the log-generating entities already made aggregate logs, the apps can just use those. If they didn't, the Rectification process can be extended with a Post-Generation Aggregation process that builds per-session logs from the per-chunk logs. It can lean on the info already in the per-chunk logs for that (the Content Collection IDentifier and a Session IDentifier). Heads up though: in line with [RFC6983], this document does not define how those aggregate logs get exchanged over the CDNI Logging interface. That's for further study and is outside the scope of this document 🧚
2.2.5. Log-Consuming Applications 👑
2.2.5.1. Maintenance and Debugging 🛠️
Logging info is super useful for spotting content delivery failures and limiting the risk they cause. It especially helps detect configuration issues 🔍
To catch faults, Logging info has to report whether CDN-delivery operations succeeded or failed. The uCDN can roll that up into KPIs. For instance, Logging info has to allow counting how many times, during a given time period, content delivery for a specific service succeeded or failed ✨
Logging info also helps CDN providers identify and troubleshoot performance degradations. It can track traffic data (like how much traffic a dCDN forwarded on behalf of a uCDN over a given period), which is really handy for CDN and network planning 💜
Some of these maintenance and debugging apps only need aggregate Logging info, which works really well with anonymization of IP addresses (as supported by this document and defined in the c-groupid field in Section 3.4.1). Sometimes, though, it's useful to access some CDNI Logging Records with full, non-anonymized IP addresses, as long as that's compatible with privacy protection. The c-groupid definition in Section 3.4.1 allows this, with very significant privacy protection limitations that are discussed in the c-groupid field definition. For example, this could help with detailed fault tracking for one particular end-user's content delivery issue 🙈
If a uCDN or CSP has a hard requirement to link a given end user to individual CDNI Logging Records (like analyzing one specific delivery after the fact, for performance-based penalties), there's another route. Instead of using aggregates containing a single client (as discussed in the c-groupid field definition), you can make sure a client identifier is embedded in request fields that get logged in a CDNI Logging Record. For example, that could be a client identifier in the URI query string or in an HTTP Header 🎀 This approach is a big win for two reasons. First, the aggregate inside the c-groupid can contain more than one client, which gives stronger privacy protection. Second, it allows a reliable identification of the client when the IP address doesn't do the job (for example, behind NAT, or where dynamic IP addresses are used and reused) 🦋
care SHOULD be taken so that the client identifiers exposed in other fields of the CDNI Records cannot themselves be linked back to actual users. this is serious, babe, don't skip it 💀
2.2.5.2. Accounting 💰
Logging info is essential for accounting. It lets uCDNs do inter-CDN billing and CSP billing 🧾 For instance, Logging info provided by dCDNs lets the uCDN compute the total traffic delivered by every dCDN for a particular Content Provider, plus the associated bandwidth usage (e.g., peak, 95th percentile), and the maximum number of simultaneous sessions over a given period of time 📈
2.2.5.3. Analytics and Reporting 📊
Analytics is all about gathering any relevant info so you can build statistics on content download, analyze user behavior, and monitor the performance and quality of content delivery 👀 For instance, Logging info lets CDN providers report on content consumption (e.g., delivered sessions per content) in a specific geographic area 🌸
Reporting is about gathering relevant info to monitor performance and quality of content delivery, and to spot delivery issues. For instance, reporting could track the average delivery throughput that end users in a given region experienced for a specific CSP or content set over a period of time ⭐
2.2.5.4. Content Protection 🔐
Content protection is about preventing and monitoring unauthorized access, misuse, modification, and denial of access to content. A set of info is logged in a CDN for security purposes. Usually, a record of access to content is collected so the CSP can detect infringements of content delivery policies and other abnormal end-user behaviors 🚨
2.2.5.5. Notions Common to Multiple Log-Consuming Applications 🧠
2.2.5.5.1. Logging Information Views 👀
Inside a given log-consuming app, different users can get different views, depending on privacy, business, and scalability constraints 💅
For example, an analytics tool run by the uCDN can give a uCDN operator one view that uses all the Logging info available to the uCDN. The same tool can show each CSP a different view that only uses the Logging info related to that CSP's content 💖
As another example, maintenance and debugging tools may show different views to different CDN operators, based on their operational role 🎀
2.2.5.5.2. Key Performance Indicators (KPIs) 📊
okay so this section is a little list of KPIs you can pull out of logs 💖 just so you know, it's for explaining things and it is NOT the full list, bestie 🎀
Multiple log-consuming applications, like analytics, monitoring, and maintenance apps, usually compute and track these KPIs ✨
In a CDNI setup, the KPIs might get computed by the uCDN or the dCDN, depending on the situation. But it's usually the uCDN doing the math 💅 because the uCDN and its dCDNs can have different definitions of KPIs, and some KPIs need a view of every delivery the uCDN and all its dCDNs handled. literally so much coordination 😭
Here are some important KPI examples:
- Number of delivery requests received from end users in a given region for each piece of content, during a given period of time (e.g., hour/day/week/month) 🍓
- Percentage of delivery successes/failures among the aforementioned requests 🌈
- Number of failures listed by failure type (e.g., HTTP error code) for requests received from end users in a given region and for each piece of content, during a given period of time (e.g., hour/day/week/month) 💀
- Number and cause of premature delivery termination for end users in a given region and for each piece of content, during a given period of time (e.g., hour/day/week/month) 🙈
- Maximum and mean number of simultaneous sessions established by end users in a given region, for a given Content Provider, and during a given period of time (e.g., hour/day/week/month) 👑
- Volume of traffic delivered for sessions established by end users in a given region, for a given Content Provider, and during a given period of time (e.g., hour/day/week/month) 🦋
- Maximum, mean, and minimum delivery throughput for sessions established by end users in a given region, for a given Content Provider, and during a given period of time (e.g., hour/day/week/month) 🔥
- Cache-hit and byte-hit ratios for requests received from end users in a given region for each piece of content, during a given period of time (e.g., hour/day/week/month) 💜
- Top 10 most popularly requested contents (during a given day/week/month) ⭐
- Terminal type (mobile, PC, Set-Top Box (STB), if this information can be acquired from the browser type inferred from the User Agent string, for example) 🧚
Additional KPIs can be computed from sources of information other than the Logging information, like data collected by a content portal or by specific client-side application programming interfaces. Those KPIs are out of scope for this document, so no peeking 🙈
The KPIs used really depend on which log-consuming application you're looking at. The CDN operator may care about different metrics than the CSP does 🫶 CDN operators are often super into delivery and acquisition performance KPIs, info about Surrogates' performance, caching info to evaluate the cache-hit ratio, and info about delivered file size to compute the volume of content delivered during peak hour, etc.
Some KPIs, like the ones giving an instantaneous view of active sessions for a given CSP's content, are only really useful if they arrive in a timely manner. Other KPIs, like ones averaged over a long period of time, can be provided in non-real-time 🌸
3. CDNI Logging File 📁
3.1. Rules
okay so this spec uses the Augmented Backus-Naur Form (ABNF) notation and core rules of [RFC5234]. Specifically, this document uses the following rules from [RFC5234]:
CR = %x0D ; carriage return
ALPHA = %x41-5A / %x61-7A ; A-Z / a-z
DIGIT = %x30-39 ; 0-9
DQUOTE = %x22 ; " (Double Quote)
CRLF = CR LF ; Internet standard newline
HEXDIG = DIGIT / "A" / "B" / "C" / "D" / "E" / "F"
HTAB = %x09 ; horizontal tab
LF = %x0A ; linefeed
VCHAR = %x21-7E ; visible (printing) characters
OCTET = %x00-FF ; 8 bits of dataIt also uses the following rules from [RFC3986]:
host = as specified in Section 3.2.2 of [RFC3986].
IPv4address = as specified in Section 3.2.2 of [RFC3986].
IPv6address = as specified in Section 3.2.2 of [RFC3986].
partial-time = as specified in Section 5.6 of [RFC3339].And it defines these additional rules, which are the cute new ones 🎀:
ADDRESS = IPv4address / IPv6address
ALPHANUM = ALPHA / DIGIT
DATE = 4DIGIT "-" 2DIGIT "-" 2DIGIT
; Dates are encoded as "full-date" specified in [RFC3339].
DEC = 1*DIGIT ["." 1*DIGIT]
NAMEFORMAT = ALPHANUM *(ALPHANUM / "_" / "-")
QSTRING = DQUOTE *(NDQUOTE / PCT-ENCODED) DQUOTE
NDQUOTE = %x20-21 / %x23-24 / %x26-7E / UTF8-2 / UTF8-3 / UTF8-4
; whereby a DQUOTE is conveyed inside a QSTRING unambiguously
; by escaping it with PCT-ENCODED.
PCT-ENCODED = "%" HEXDIG HEXDIG
; percent encoding is used for escaping octets that might be
; possible in HTTP headers such as bare CR, bare LF, CR LF,
; HTAB, SP, or null. These octets are rendered with percent
; encoding in ABNF as specified by [RFC3986] in order to avoid
; considering them as separators for the Logging Records.
NHTABSTRING = 1*(SP / VCHAR)
TIME = partial-time
USER-COMMENT = *(SP / VCHAR / UTF8-2 / UTF8-3 / UTF8-4)3.2. CDNI Logging File Structure
As defined in Section 1.1, a CDNI Logging Field is an atomic Logging information element, a CDNI Logging Record is a collection of CDNI Logging fields holding all the logging info for one single logging event, and a CDNI Logging File holds a collection of CDNI Logging Records. Check out Figure 3 for the picture 🖼️ Using a file structure to transfer CDNI Logging info was picked because it's the most common practice today for swapping logging info within and across CDNs.
+----------------------------------------------------------+
|CDNI Logging File |
| |
| #Directive 1 |
| #Directive 2 |
| ... |
| #Directive P |
| |
| +------------------------------------------------------+ |
| |CDNI Logging Record 1 | |
| | +-------------+ +-------------+ +-------------+ | |
| | |CDNI Logging | |CDNI Logging | ... |CDNI Logging | | |
| | | Field 1 | | Field 2 | | Field N | | |
| | +-------------+ +-------------+ +-------------+ | |
| +------------------------------------------------------+ |
| |
| +------------------------------------------------------+ |
| |CDNI Logging Record 2 | |
| | +-------------+ +-------------+ +-------------+ | |
| | |CDNI Logging | |CDNI Logging | ... |CDNI Logging | | |
| | | Field 1 | | Field 2 | | Field N | | |
| | +-------------+ +-------------+ +-------------+ | |
| +------------------------------------------------------+ |
| |
| ... |
| |
| #Directive P+1 |
| |
| ... |
| |
| +------------------------------------------------------+ |
| |CDNI Logging Record M | |
| | +-------------+ +-------------+ +-------------+ | |
| | |CDNI Logging | |CDNI Logging | ... |CDNI Logging | | |
| | | Field 1 | | Field 2 | | Field N | | |
| | +-------------+ +-------------+ +-------------+ | |
| +------------------------------------------------------+ |
| |
| |
| #Directive P+Q |
+----------------------------------------------------------+Figure 3: Structure of Logging Files 🌿
The CDNI Logging File format is inspired by the W3C Extended Log File Format [ELF]. It is fully specified by this document, though. Anywhere this document differs from the W3C Extended Log File Format, an implementation of the CDNI Logging interface MUST comply with this document. The W3C format was the starting point, reused where possible and expanded when needed 🧁
Using a format that looks like the W3C Extended Log File Format keeps the CDNI logging format close to the intra-CDN Logging information format that CDNs commonly use today, so there's way less systematic translation at the CDN/CDNI boundary. so smart, right? 😤
A CDNI Logging File MUST contain a sequence of lines containing US-ASCII characters [CHAR_SET] terminated by CRLF. Each line of a CDNI Logging File MUST contain either a directive or a CDNI Logging Record 🫶
Directives record info about the CDNI Logging process itself. Lines containing directives MUST begin with the "#" character. Directives are specified in Section 3.3.
Logging Records provide the actual details of the logged event. Logging Records are specified in Section 3.4.
The CDNI Logging File has a specific structure. It always starts with a directive line, and the first directive it contains MUST be the version. The directive lines together form a group that contains at least one directive line. Each directives group is followed by a group of Logging Records. The records group contains zero or more actual Logging Record lines about the event being logged. A record line consists of the values for all or a subset of the possible Logging fields defined within the scope of the record-type directive. These values MUST appear in the order defined by the fields directive.
Note that future extensions MUST be compliant with the previous description. The following examples show the structure of a CDNILOGFILE, as currently defined by the record-type "cdni_http_request_v1." 📝
DIRLINE = "#" directive CRLF
DIRGROUP = 1*DIRLINE
RECLINE = <any subset of record values that match what is expected
according to the fields directive within the immediately preceding
DIRGROUP>
RECGROUP = *RECLINE
CDNILOGFILE = 1*(DIRGROUP RECGROUP)3.3. CDNI Logging Directives 💅✨
Okay so, a CDNI Logging directive line is the directive name, then ":" and an HTAB, then the directive value. Simple, iconic, let's go 🎀
Directive names MUST be of the format NAMEFORMAT. Every directive name MUST be registered in the "CDNI Logging Directives Names" registry. Directive names are case-insensitive as per the basic ABNF ([RFC5234]). Unknown directives MUST be ignored 🙈. Directive values can come in various formats, and all the possible directive values for the record-type "cdni_http_request_v1" get detailed in this section 🌸.
Here's the vibe: the example shows the structure of a directive and lists strictly the directive values that are currently defined in version "cdni/1.0" of the CDNI Logging File 🦋.
directive = DIRNAME ":" HTAB DIRVAL
DIRNAME = NAMEFORMAT
FIENAME = <any CDNI Logging field name registered in the CDNI
Logging Field Names registry (Section 6.4) that is valid for the
record type specified in the record-type directive.>
DIRVAL = NHTABSTRING / QSTRING / host / USER-COMMENT / FIENAME
*(HTAB FIENAME) / 64HEXDIGAn implementation of the CDNI Logging interface MUST support all of the following directives, listed below by their directive name 💖:
- Version:
- Format: NHTABSTRING
- Directive value: Indicates the version of the CDNI Logging File format. The entity transmitting a CDNI Logging File as per the present document MUST set the value to "cdni/1.0". In the future, other versions of the CDNI Logging File might be specified, and those would use a value different from "cdni/1.0", which lets the entity receiving the file identify the matching version 👑. CDNI Logging File versions are case-insensitive as per the basic ABNF ([RFC5234]).
- Occurrence: There MUST be one and only one instance of this directive per CDNI Logging File. It MUST be the first line of the CDNI Logging File ✨.
- Example:
version: HTAB cdni/1.0
- UUID:
- Format: NHTABSTRING
- Directive value: This is a Uniform Resource Name (URN) from the Universally Unique IDentifier (UUID) URN namespace specified in [RFC4122]. The UUID contained in the URN uniquely identifies the CDNI Logging File 🔥.
- Occurrence: There MUST be one and only one instance of this directive per CDNI Logging File.
- Example:
UUID: HTAB NHTABSTRING
- Claimed-origin:
- Format: Host
- Directive value: This contains the claimed identification of the entity transmitting the CDNI Logging File (e.g., the host in a dCDN supporting the CDNI Logging interface) or the entity responsible for transmitting the CDNI Logging File (e.g., the dCDN) 🦋.
- Occurrence: There MUST be zero or exactly one instance of this directive per CDNI Logging File. This directive MAY be included by the dCDN. It MUST NOT be included or modified by the uCDN 🙅.
- Example:
claimed-origin: HTAB host
- Established-origin:
- Format: Host
- Directive value: This contains the identification, as established by the entity receiving the CDNI Logging File, of the entity transmitting the CDNI Logging File (e.g., the host in a dCDN supporting the CDNI Logging interface) or the entity responsible for transmitting the CDNI Logging File (e.g., the dCDN) 🧚.
- Occurrence: There MUST be zero or exactly one instance of this directive per CDNI Logging File. This directive MAY be added by the uCDN (e.g., before storing the CDNI Logging File). It MUST NOT be included by the dCDN. The mechanisms the uCDN uses to establish and validate the entity responsible for the CDNI Logging File are outside the scope of this document. We observe that, in particular, this may be achieved through authentication mechanisms that are part of the transport layer of the CDNI Logging File pull mechanism (Section 4.2) 🔐.
- ABNF example:
established-origin: HTAB host
- Remark:
- Format: USER-COMMENT
- Directive value: This contains comment information. Data in this field is to be ignored by analysis tools 🙈.
- Occurrence: There MAY be zero, one, or any number of instances of this directive per CDNI Logging File.
- Example:
remark: HTAB USER-COMMENT
- Record-type:
- Format: NAMEFORMAT
- Directive value: Indicates the type of the CDNI Logging Records that follow this directive, until another record-type directive appears in the CDNI Logging File (or the end of the CDNI Logging File). This can be any CDNI Logging Record type registered in the "CDNI Logging record-types" registry (Section 6.3). For example, this may be "cdni_http_request_v1" as specified in Section 3.4.1. CDNI Logging record-types are case-insensitive as per the basic ABNF ([RFC5234]) 🍓.
- Occurrence: There MUST be at least one instance of this directive per CDNI Logging File. The first instance of this directive MUST precede a fields directive and MUST precede all CDNI Logging Records 💜.
- Example:
record-type: HTAB cdni_http_request_v1
- Fields:
- Format:
FIENAME *(HTAB FIENAME) ; where FIENAME can take any CDNI Logging field name registered in the "CDNI Logging Field Names" registry (Section 6.4) that is valid for the record type specified in the record-type directive. - Directive value: This lists the names of all the fields for which a value is to appear in the CDNI Logging Records that follow this instance of the directive (until another instance of this directive appears in the CDNI Logging File). The names of the fields, as well as their occurrences, MUST comply with the corresponding rules specified in the document referenced in the "CDNI Logging record-types" registry (Section 6.3) for the corresponding CDNI Logging record-type 🌈.
- Occurrence: There MUST be at least one instance of this directive per record-type directive. The first instance of this directive for a given record-type MUST appear before any CDNI Logging Record for this record-type. One situation where more than one instance of the fields directive can appear within a given CDNI Logging File is when there's a change in the middle of a fairly large logging period, and the uCDN and dCDN agreed on a different set of fields to exchange. Multiple occurrences let records with the old set of fields and records with the new set of fields live inside the same Logging File 🧁.
- Example:
fields: HTAB FIENAME * (HTAB FIENAME)
- Format:
- SHA256-hash:
- Format: 64HEXDIG
- Directive value: This directive lets you detect a corrupted CDNI Logging File 🛡️. That's super useful if something goes wrong on the file system of the dCDN Logging system and ends up truncating a Logging File 😭. The valid SHA256-hash value is included in this directive by the entity that transmits the CDNI Logging File. It MUST be computed by applying the SHA-256 ([RFC6234]) cryptographic hash function to the CDNI Logging File, including all the directives and Logging Records, up to the SHA256-hash directive itself, excluding the SHA256-hash directive itself. The SHA256-hash value MUST be represented as a 64-digit hexadecimal number encoded in US-ASCII (representing a 256 bit hash value). The entity receiving the CDNI Logging File also computes the SHA-256 hash on the received file in a similar way, and compares it to the value of the SHA256-hash directive. If the two values are equal, the received CDNI Logging File is considered non-corrupted. If they're different, the received CDNI Logging File is considered corrupted. The behavior of the entity that received a corrupted CDNI Logging File is outside the scope of this specification; we note that the entity MAY attempt to pull the same CDNI Logging File from the transmitting entity again. If the entity receiving a non-corrupted CDNI Logging File adds an established-origin directive, it MUST then recompute and update the SHA256-hash directive so that it also protects the added established-origin directive 🔒.
- Occurrence: There MUST be zero or exactly one instance of this directive. There SHOULD be exactly one instance of this directive. One situation where that directive could be omitted is where integrity protection is already provided via another mechanism (for example, if an integrity hash is associated with the CDNI Logging File out of band through the CDNI Logging Feed (Section 4.1) leveraging ATOM extensions such as those proposed in [ATOMPUB]). When present, the SHA256-hash field MUST be the last line of the CDNI Logging File 🏁.
- Example:
SHA256-hash: HTAB 64HEXDIG
A uCDN-side implementation of the CDNI Logging interface MUST ignore a CDNI Logging File that does not comply with the occurrences specified above for each and every directive. For example, a uCDN-side implementation receiving a CDNI Logging File with zero occurrences of the version directive, or with two occurrences of the SHA256-hash, MUST ignore this CDNI Logging File 🚫.
An entity receiving a CDNI Logging File with a value set to "cdni/1.0" MUST process the CDNI Logging File as per the present document. An entity receiving a CDNI Logging File with a value set to a different value MUST process the CDNI Logging File as per the specification referenced in the "CDNI Logging File version" registry (see Section 6.1) if the implementation supports that specification, and MUST ignore the CDNI Logging File otherwise 🌸.
3.4. CDNI Logging Records ✨
okay bestie, so a CDNI Logging Record is basically a sequence of CDNI Logging fields that all describe that one single record 💖
CDNI Logging fields MUST be separated by the horizontal tabulation (HTAB) character. no skipping this one 🫶
To keep things readable, they borrowed a prefix trick from the W3C Extended Log File Format [ELF] 🎀 so field names start with a little prefix that tells you who's doing what. Here's the vibe for each one:
c-= the User Agent that issues the request (the "client" in W3C Extended Log Format) 🦋d-= the dCDN, from the point of view of a CDN acting as a uCDN 🌸s-= the dCDN Surrogate that serves the request (the "server" in W3C Extended Log Format) 💜u-= the uCDN, from the point of view of a CDN acting as a dCDN 🌈cs-= communication from the User Agent towards the dCDN Surrogate 🍓sc-= communication from the dCDN Surrogate towards the User Agent 🧚
An implementation of the CDNI Logging interface, as per this spec, MUST support the CDNI HTTP Request Logging Record in Section 3.4.1. non-negotiable, periodt 👑
A CDNI Logging Record holds the values for the fields listed in the last fields directive before the current log line. the values show up in whatever order the field names appear in that directive, so the directive is the boss here ✨ There SHOULD be no dependency between the various field values, so they can stand on their own 💅
3.4.1. HTTP Request Logging Record
okay this is the main event 🎀 This section defines the CDNI Logging Record with the record-type cdni_http_request_v1. It applies to content delivery performed by the dCDN using HTTP/1.0 ([RFC1945]), HTTP/1.1 ([RFC7230] [RFC7231] [RFC7232] [RFC7233] [RFC7234] [RFC7235]), or HTTPS ([RFC2818] [RFC7230]).
ngl this next bit is so good 😭 With HTTPS delivery, there may be value in logging extra info about how HTTP runs over Transport Layer Security (TLS). That's outside the scope of this document, though, and it might get handled in a future document that defines another CDNI Logging Record or another version of the HTTP Request Logging Record.
The cdni_http_request_v1 record-type is also expected to apply to HTTP/2 [RFC7540], because a core design tenet of HTTP/2 is to keep the HTTP/1.1 semantics. Just like with HTTPS, HTTP/2 delivery may have value in logging extra stuff specific to what HTTP/2 adds (for example, connection identification, stream identification, stream priority, and flow control). That additional info is also outside the scope of this document, and it might be covered later by another CDNI Logging Record or another version of the HTTP Request Logging Record 🦋
The cdni_http_request_v1 record-type contains the following CDNI Logging fields, listed by their field name:
Date:- Format:
DATE - Field value: The date on which the processing of the request completed on the Surrogate.
- Occurrence: There MUST be one and only one instance of this field.
- Format:
Time:- Format:
TIME - Field value: The time, which MUST be expressed in Coordinated Universal Time (UTC), at which the processing of the request completed on the Surrogate.
- Occurrence: There MUST be one and only one instance of this field.
- Format:
Time-taken:- Format:
DEC - Field value: Decimal value of the duration, in seconds, between the start of the processing of the request and the completion of the request processing (e.g., completion of delivery) by the Surrogate.
- Occurrence: There MUST be one and only one instance of this field.
- Format:
c-groupid:- Format:
NHTABSTRING - Field value: An opaque identifier for an aggregate set of clients, derived from the client IPv4 or IPv6 address in the request received by the Surrogate and/or other network-level identifying information. The c-groupid serves to group clients into aggregates. Example aggregates include civil geolocation information (the country, second-level administrative division, or postal code from which the client is presumed to make the request based on a geolocation database lookup) or network topological information (e.g., the BGP autonomous system (AS) number announcing the prefix containing the address). The c-groupid MAY be structured, e.g.,
US/TN/MEM/38138. Agreement between the dCDN and the uCDN on a mapping between IPv4 and IPv6 addresses and aggregates is presumed to occur out of band. The aggregation mapping SHOULD be chosen such that each aggregate contains more than one client.- When the aggregate is chosen so that it contains a single client (e.g., to allow more detailed analytics, or to allow a posteriori analysis of individual delivery, for example, in situations of performance-based penalties), the c-groupid MAY be structured where some elements identify aggregates and one element identifies the client, e.g.,
US/TN/MEM/38138/43a5bdd6-95c4-4d62-be65-7410df0021e2. In the case where the aggregate is chosen so that it contains a single client:- The element identifying the client SHOULD be algorithmically generated (from the client IPv4 or IPv6 address in the request received by the Surrogate and/or other network-level identifying information) in a way that SHOULD NOT be linkable back to the global addressing context and that SHOULD vary over time (to offer protection against long-term attacks).
- It is RECOMMENDED that the mapping varies at least once every 24 hours.
- The algorithmic mapping and variation over time can, in some cases, allow the uCDN (with the knowledge of the algorithm, the time variation, and the associated attributes and keys) to reconstruct the actual client IPv4 or IPv6 address and/or other network-level identifying information when required (e.g., to allow a posteriori analysis of individual delivery, for example, in situations of performance-based penalties). However, these end-user addresses SHOULD only be reconstructed on-demand and the CDNI Logging File SHOULD only be stored with the anonymized c-groupid value.
- Allowing reconstruction of client address information carries with it grave risks to end-user privacy. Since the c-groupid is, in this case, equivalent in identification power to a client IP address, its use may be restricted by regulation or law as personally identifiable information. For this reason, such use is NOT RECOMMENDED.
- One method for mapping that MAY be supported by implementations relies on a symmetric key that is known only to the uCDN, the dCDN, and the HMAC-based Extract-and-Expand Key Derivation Function (HKDF) key derivation ([RFC5869]), as will be used in TLS 1.3 ([TLS-1.3]). When that method is used:
- The uCDN and dCDN need to agree on the "salt" and "input keying material", as described in Section 2.2 of [RFC5869], and the initial "info" parameter (which could be something like the business names of the two organizations in UTF-8, concatenated), as described in Section 2.3 of [RFC5869]. The hash SHOULD be either SHA-2 or SHA-3 [SHA-3], and the encryption algorithm SHOULD be 128-bit AES [AES] in Galois Counter Mode (GCM) [GCM] (AES-GCM) or better. The pseudorandom key (PRK) SHOULD be chosen by both parties contributing alternate random bytes until sufficient length exists. After the initial setup, client-information can be encrypted using the key generated by the "expand" step of Section 2.3 of [RFC5869]. The encrypted value SHOULD be hex encoded or base64 encoded (as specified in Section 4 of [RFC4648]). At the agreed-upon expiration time, a new key SHOULD be generated and used. New keys SHOULD be indicated by prefixing the key with a special character such as an exclamation point. In this way, shorter lifetimes can be used as needed.
- When the aggregate is chosen so that it contains a single client (e.g., to allow more detailed analytics, or to allow a posteriori analysis of individual delivery, for example, in situations of performance-based penalties), the c-groupid MAY be structured where some elements identify aggregates and one element identifies the client, e.g.,
- Occurrence: There MUST be one and only one instance of this field.
- Format:
s-ip:- Format:
ADDRESS - Field value: The IPv4 or IPv6 address of the Surrogate that served the request (i.e., the "server" address).
- Occurrence: There MUST be zero or exactly one instance of this field.
- Format:
s-hostname:- Format:
Host - Field value: The hostname of the Surrogate that served the request (i.e., the "server" hostname).
- Occurrence: There MUST be zero or exactly one instance of this field.
- Format:
s-port:- Format:
1*DIGIT - Field value: The destination TCP port (i.e., the "server" port) in the request received by the Surrogate.
- Occurrence: There MUST be zero or exactly one instance of this field.
- Format:
cs-method:- Format:
NHTABSTRING - Field value: This is the method of the request received by the Surrogate. In the case of HTTP delivery, this is the HTTP method in the request.
- Occurrence: There MUST be one and only one instance of this field.
- Format:
cs-uri:- Format:
NHTABSTRING - Field value: This is the "effective request URI" of the request received by the Surrogate, as specified in [RFC7230]. It complies with the "http" URI scheme or the "https" URI scheme as specified in [RFC7230]. Note that cs-uri can be privacy sensitive. In that case, and where appropriate, u-uri could be used instead of cs-uri.
- Occurrence: There MUST be zero or exactly one instance of this field.
- Format:
u-uri:- Format:
NHTABSTRING - Field value: This is a complete URI, derived from the "effective request URI" ([RFC7230]) of the request received by the Surrogate (i.e., the cs-uri) but transformed by the entity generating or transmitting the CDNI Logging Record, in a way that is agreed upon between the two ends of the CDNI Logging interface, so the transformed URI is meaningful to the uCDN. For example, the two ends of the CDNI Logging interface could agree that the u-uri is constructed from the cs-uri by removing the part of the hostname that exposes which individual Surrogate actually performed the delivery. The details of modification performed to generate the u-uri, as well as the mechanism to agree on these modifications between the two sides of the CDNI Logging interface, are outside the scope of the present document.
- Occurrence: There MUST be zero or exactly one instance of this field.
- Format:
- Occurrence: There MUST be one and only one instance of this field. 💅
protocol🧚- Format:
NHTABSTRING - Field value: This is the value of the HTTP-Version field as specified in [RFC7230] of the Request-Line of the request received by the Surrogate (e.g.,
"HTTP/1.1"). - Occurrence: There MUST be one and only one instance of this field. 🎀
- Format:
sc-status🔥- Format:
3DIGIT - Field value: This is the Status-Code in the response from the Surrogate. In the case of HTTP delivery, this is the HTTP Status-Code in the HTTP response.
- Occurrence: There MUST be one and only one instance of this field. 💖
- Format:
sc-total-bytes🍓- Format:
1*DIGIT - Field value: This is the total number of bytes of the response sent by the Surrogate in response to the request. In the case of HTTP delivery, this includes the bytes of the Status-Line, the bytes of the HTTP headers, and the bytes of the message-body.
- Occurrence: There MUST be one, and only one, instance of this field. 🌸
- Format:
sc-entity-bytes🦋- Format:
1*DIGIT - Field value: This is the number of bytes of the message-body in the HTTP response sent by the Surrogate in response to the request. This does not include the bytes of the Status-Line or the bytes of the HTTP headers.
- Occurrence: There MUST be zero or exactly one instance of this field. 🙈
- Format:
cs(insert_HTTP_header_name_here)✨- Format:
QSTRING - Field value: The value of the HTTP header (identified by the
insert_HTTP_header_name_herein the CDNI Logging field name) as it appears in the request processed by the Surrogate, but prepended by a DQUOTE and appended by a DQUOTE. For example, when the CDNI Logging field name (FIENAME) listed in the preceding fields directive iscs(User-Agent), this CDNI Logging field value contains the value of the User-Agent HTTP header as received by the Surrogate in the request it processed, but prepended by a DQUOTE and appended by a DQUOTE. If the HTTP header, as it appeared in the request processed by the Surrogate, contains one or more DQUOTE, each DQUOTE MUST be escaped with percent encoding. For example, if the HTTP header containsMy_Header"value", then the field value of thecs(insert_HTTP_header_name_here)is"My_Header%x22value%x22". The entity transmitting the CDNI Logging File MUST ensure that the respectiveinsert_HTTP_header_name_hereof thecs(insert_HTTP_header_name_here)listed in the fields directive comply with HTTP specifications. In particular, this field name does not include any HTAB, since this would prevent proper parsing of the fields directive by the entity receiving the CDNI Logging File. - Occurrence: There MAY be zero, one, or any number of instance of this field. 🌈
- Format:
sc(insert_HTTP_header_name_here)🧁- Format:
QSTRING - Field value: The value of the HTTP header (identified by the
insert_HTTP_header_name_herein the CDNI Logging field name) as it appears in the response issued by the Surrogate to serve the request, but prepended by a DQUOTE and appended by a DQUOTE. If the HTTP header, as it appeared in the request processed by the Surrogate, contains one or more DQUOTEs, each DQUOTE MUST be escaped with percent encoding. For example, if the HTTP header containsMy_Header"value", then the field value of thesc(insert_HTTP_header_name_here)is"My_Header%x22value%x22". The entity transmitting the CDNI Logging File MUST ensure that the respectiveinsert_HTTP_header_name_hereof thecs(insert_HTTP_header_name_here)listed in the fields directive comply with HTTP specifications. In particular, this field name does not include any HTAB, since this would prevent proper parsing of the fields directive by the entity receiving the CDNI Logging File. - Occurrence: There MAY be zero, one, or any number of instances of this field. For a given
insert_HTTP_header_name_here, there MUST be zero or exactly one instance of this field. 🫶
- Format:
s-ccid👑- Format:
QSTRING - Field value: This contains the value of the Content Collection IDentifier (CCID) associated by the uCDN to the content served by the Surrogate via the CDNI Metadata interface ([CDNI-META]), prepended by a DQUOTE and appended by a DQUOTE. If the CCID conveyed in the CDNI Metadata interface contains one or more DQUOTEs, each DQUOTE MUST be escaped with percent encoding. For example, if the CCID conveyed in the CDNI Metadata interface is
My_CCIDD"value", then the field value of thes-ccidis"My_CCID%x22value%X22". - Occurrence: There MUST be zero or exactly one instance of this field. For a given
insert_HTTP_header_name_here, there MUST be zero or exactly one instance of this field. ⭐
- Format:
s-sid🔮- Format:
QSTRING - Field value: This contains the value of a Session IDentifier (SID) generated by the dCDN for a specific HTTP session, prepended by a DQUOTE and appended by a DQUOTE. In particular, for an HTTP Adaptive Streaming (HAS) session, the SID value is included in the Logging Record for every content chunk delivery of that session in view of facilitating the later correlation of all the per-content chunk log records of a given HAS session. See Section 3.4.2.2. of [RFC6983] for more discussion on the concept of Session IDentifier in the context of HAS. If the SID conveyed contains one or more DQUOTEs, each DQUOTE MUST be escaped with percent-encoding. For example, if the SID is
My_SID"value", then the field value of thes-sidis"My_SID%x22value%x22". - Occurrence: There MUST be zero or exactly one instance of this field. 🧚♀️
- Format:
s-cached💜- Format:
1DIGIT - Field value: This characterizes whether or not the Surrogate served the request using content already stored on its local cache. The allowed values are
"0"(for miss) and"1"(for hit)."1"MUST be used when the Surrogate did serve the request exclusively using content already stored on its local cache."0"MUST be used otherwise (including cases where the Surrogate served the request using some, but not all, content already stored on its local cache). Note that a"0"only means a cache miss in the Surrogate and does not provide any information on whether or not the content was already stored in another device of the dCDN, i.e., whether this was a "dCDN hit" or a "dCDN miss". - Occurrence: There MUST be zero or exactly one instance of this field. 🥹
- Format:
CDNI Logging field names are case-insensitive as per the basic ABNF ([RFC5234]). The "fields" directive corresponding to an HTTP Request Logging Record MUST contain all the fields names whose occurrence is specified above as "[t]here MUST be one and only one instance of this field." The corresponding fields value MUST be present in every HTTP Request Logging Record.
The "fields" directive corresponding to an HTTP Request Logging Record MAY list all the fields values whose occurrence is specified above as "[t]here MUST be zero or exactly one instance of this field" or "[t]here MAY be zero, one, or any number of instances of this field." The set of such field names actually listed in the "fields" directive is selected by the CDN generating the CDNI Logging File based on agreements between the interconnected CDNs established through mechanisms outside the scope of this specification (e.g., contractual agreements). When such a field name is not listed in the "fields" directive, the corresponding field value MUST NOT be included in the Logging Record. When such a field name is listed in the "fields" directive, the corresponding field value MUST be included in the Logging Record; if the value for the field is not available, this MUST be conveyed via a dash character ("-").
The fields names listed in the "fields" directive MAY be listed in the order in which they are listed in Section 3.4.1 or MAY be listed in any other order.
Logging some specific fields from HTTP requests and responses can introduce serious security and privacy risks. For example, cookies will often contain (months) long-lived token values that can be used to log into a service as the relevant user. Similar values may be included in other header fields or within URLs or elsewhere in HTTP requests and responses. Centralizing such values in a CDNI Logging File can therefore represent a significant increase in risk both for the user and the web service provider, but also for the CDNs involved. Therefore, implementations ought to attempt to lower the probability of such bad outcomes, e.g., by only allowing a configured set of headers to be added to CDNI Logging Records, or by not supporting wildcard selection of HTTP request/response fields to add. Such mechanisms can reduce the probability that security (or privacy) sensitive values are centralized in CDNI Logging Files. Also, when agreeing on which HTTP request/response fields are to be provided in CDNI Logging Files, the uCDN and dCDN administrators ought to consider these risks. Furthermore, CDNs making use of c-groupid to identify an aggregate of clients rather than individual clients ought to realize that, by logging certain header fields, they may create the possibility to re-identify individual clients. In these cases, heeding the above advice, or not logging header fields at all, is particularly important if the goal is to provide logs that do not identify individual clients. 🚨
A dCDN-side implementation of the CDNI Logging interface MUST implement all the following Logging fields in a CDNI Logging Record of record-type "cdni_http_request_v1" and MUST support the ability to include valid values for each of them:
datetimetime-takenc-groupids-ips-hostnames-portcs-methodcs-uriu-uriprotocolsc-statussc-total-bytessc-entity-bytescs(insert_HTTP_header_name_here)sc(insert_HTTP_header_name_here)s-cached
A dCDN-side implementation of the CDNI Logging interface MAY support the following Logging fields in a CDNI Logging Record of record-type "cdni_http_request_v1":
s-ccids-sid
If a dCDN-side implementation of the CDNI Logging interface supports these fields, it MUST support the ability to include valid values for them.
An uCDN-side implementation of the CDNI Logging interface MUST be able to accept CDNI Logging Files with CDNI Logging Records of record-type "cdni_http_request_v1" containing any CDNI Logging Field defined in Section 3.4.1 as long as the CDNI Logging Record and the CDNI Logging File are compliant with the present document. 🩷
Okay bestie, so the first thing you need to know is that a uCDN-side implementation that gets a CDNI Logging File with HTTP Request Logging Records missing field values for exactly the names in the previous "fields" directive MUST ignore those Records and MUST accept the rest. Rude to the broken ones, lol 💅🫶
Also, the text MUST be sanitized before it gets logged 🧼 To keep the Logging File correct, null, bare CR, bare LF, and HTAB have to be removed by percent-encoding them. That way they can't get mixed up with the Logging Record separators 🎀
3.5. CDNI Logging File Extension
Okay, so a CDNI Logging File is made of blocks of directives and blocks of matching records 🦋 Which directives are supported depends on the CDNI Logging File Format version. The full set for version "cdni/1.0" is in Section 3.3. We're not expecting the directive list to grow much, but if it does, the new directive MUST be defined and registered in the "CDNI Logging Directive Names" registry, as described in Figure 9 🌸 A new version MUST also be defined and registered in the "CDNI Logging File version" registry, as described in Section 6.2. For example, if you added a new CDNI Logging Directive "foo" to the set for "cdni/1.0" from Section 3.3, you'd need to register both "foo" and a new version like "CDNI/2.0". That version would have all the existing "cdni/1.0" directives plus "foo" ✨
Logging needs are always changing, so the fields we log will change and expand too 📈 When you add new fields, the new fields MUST be defined and registered in the "CDNI Logging Field Names" registry, as described in Section 6.4, and a new record-type MUST be defined and registered in the "CDNI Logging record-types" registry, as described in Section 6.3. For example, if you added a new field "c-bar" to the set for "cdni_http_request_v1" from Section 3.4.1, you'd register "c-bar" AND a new record-type like "cdni_http_request_v2". That record-type would include all the existing "cdni_http_request_v1" fields plus "c-bar" 💜
3.6. CDNI Logging File Examples
Let's look at the upstream CDN and the downstream CDN-labeled uCDN and dCDN-1 from Figure 1 🧚 When dCDN-1 acts as a downstream CDN for uCDN and delivers content on uCDN's behalf, dCDN-1 includes the CDNI Logging Records for those deliveries in the CDNI Logging Files it gives to uCDN. Here's an example CDNI Logging File that dCDN-1 sends to uCDN, shown in Figure 4 👑
#version:<HTAB>cdni/1.0<CRLF>
#UUID:<HTAB>urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6<CRLF>
#claimed-origin:<HTAB>cdni-logging-entity.dcdn-1.example.com<CRLF>
#record-type:<HTAB>cdni_http_request_v1<CRLF>
#fields:<HTAB>date<HTAB>time<HTAB>time-taken<HTAB>c-groupid<HTAB>
cs-method<HTAB>u-uri<HTAB>protocol<HTAB>
sc-status<HTAB>sc-total-bytes<HTAB>cs(User-Agent)<HTAB>
cs(Referer)<HTAB>s-cached<CRLF>
2013-05-17<HTAB>00:38:06.825<HTAB>9.058<HTAB>US/TN/MEM/38138<HTAB>
GET<HTAB>
http://cdni-ucdn.dcdn-1.example.com/video/movie100.mp4<HTAB>
HTTP/1.1<HTAB>200<HTAB>6729891<HTAB>"Mozilla/5.0
(Windows; U; Windows NT 6.0; en-US) AppleWebKit/533.4 (KHTML, like
Gecko) Chrome/5.0.375.127 Safari/533.4"<HTAB>
"host1.example.com"<HTAB>1<CRLF>
2013-05-17<HTAB>00:39:09.145<HTAB>15.32<HTAB>FR/PACA/NCE/06100<HTAB>
GET<HTAB>
http://cdni-ucdn.dcdn-1.example.com/video/movie118.mp4<HTAB>
HTTP/1.1<HTAB>200<HTAB>15799210<HTAB>"Mozilla/5.0
(Windows; U; Windows NT 6.0; en-US) AppleWebKit/533.4 (KHTML, like
Gecko) Chrome/5.0.375.127 Safari/533.4"<HTAB>
"host1.example.com"<HTAB>1<CRLF>
2013-05-17<HTAB>00:42:53.437<HTAB>52.879<HTAB>US/TN/MEM/38138<HTAB>
GET<HTAB>
http://cdni-ucdn.dcdn-1.example.com/video/picture11.mp4<HTAB>
HTTP/1.0<HTAB>200<HTAB>97234724<HTAB>"Mozilla/5.0
(Windows; U; Windows NT 6.0; en-US) AppleWebKit/533.4 (KHTML, like
Gecko) Chrome/5.0.375.127 Safari/533.4"<HTAB>
"host5.example.com"<HTAB>0<CRLF>
#SHA256-hash:<HTAB> 64-hexadecimal-digit hash value <CRLF>Figure 4: CDNI Logging File Example
If uCDN can establish, by some means (for example, TLS authentication when it pulls the CDNI Logging File), who it pulled the file from, it can add an established-origin directive to the CDNI Logging File like this 🔐
#established-origin:<HTAB>cdni-logging-entity.dcdn-1.example.com<CRLF>As Figure 2 shows, uCDN then ingests the matching CDNI Logging Records into its Collection process, right alongside the Logging Records it generated itself 🤝 That means uCDN can aggregate Logging Records for its own deliveries (from locally generated Records) AND for deliveries done by its downstream CDN(s) 🫶 After Filtering and Rectification (see Figure 2), that combined info can be used by log-consuming applications that count deliveries from uCDN and all of its downstream CDNs. Iconic teamwork 👑
Now, the time between
- when a delivery is completed in dCDN, and
- when the matching Logging Record is ingested by the Collection process in uCDN
depends on a bunch of things 🕰️ Like the Logging Period that uCDN and dCDN agreed on, how long uCDN waits before pulling the CDNI Logging File once it's advertised in the CDNI Logging Feed, and how long the pull takes. So if you look at the Logging Records the Collection process in uCDN aggregates in a given time interval, there could be a permanent, significant timing difference between the CDNI Logging Records from dCDN and the Logging Records generated locally 😭 For example, in one time interval, the Collection process in uCDN might be aggregating local Records for deliveries from the last hour, while the CDNI Logging Records from dCDN are for deliveries from the hour before that. Timelines, bestie 💀
Say, for some reason (for example, a Surrogate bug 🐛), dCDN-1 couldn't collect the total number of bytes in the responses the Surrogate sent. In other words, the value for sc-total-bytes isn't available. Then the matching CDNI Logging Records would have a dash character ("-") in place of the sc-total-bytes value, as specified in Section 3.4.1 🙈 In that case, the CDNI Logging File that dCDN-1 sends to uCDN looks like Figure 5 below:
#version:<HTAB>cdni/1.0<CRLF>
#UUID:<HTAB>urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6<CRLF>
#claimed-origin:<HTAB>cdni-logging-entity.dcdn-1.example.com<CRLF>
#record-type:<HTAB>cdni_http_request_v1<CRLF>
#fields:<HTAB>date<HTAB>time<HTAB>time-taken<HTAB>c-groupid<HTAB>
cs-method<HTAB>u-uri<HTAB>protocol<HTAB>
sc-status<HTAB>sc-total-bytes<HTAB>cs(User-Agent)<HTAB>
cs(Referer)<HTAB>s-cached<CRLF>
2013-05-17<HTAB>00:38:06.825<HTAB>9.058<HTAB>US/TN/MEM/38138<HTAB>
GET<HTAB>
http://cdni-ucdn.dcdn-1.example.com/video/movie100.mp4<HTAB>
HTTP/1.1<HTAB>200<HTAB>-<HTAB>"Mozilla/5.0
(Windows; U; Windows NT 6.0; en-US) AppleWebKit/533.4 (KHTML, like
Gecko) Chrome/5.0.375.127 Safari/533.4"<HTAB>
"host1.example.com"<HTAB>1<CRLF>
2013-05-17<HTAB>00:39:09.145<HTAB>15.32<HTAB>FR/PACA/NCE/06100<HTAB>
GET<HTAB>
http://cdni-ucdn.dcdn-1.example.com/video/movie118.mp4<HTAB>
HTTP/1.1<HTAB>200<HTAB>-<HTAB>"Mozilla/5.0
(Windows; U; Windows NT 6.0; en-US) AppleWebKit/533.4 (KHTML, like
Gecko) Chrome/5.0.375.127 Safari/533.4"<HTAB>
"host1.example.com"<HTAB>1<CRLF>
2013-05-17<HTAB>00:42:53.437<HTAB>52.879<HTAB>US/TN/MEM/38138<HTAB>
GET<HTAB>
http://cdni-ucdn.dcdn-1.example.com/video/picture11.mp4<HTAB>
HTTP/1.0<HTAB>200<HTAB>-<HTAB>"Mozilla/5.0
(Windows; U; Windows NT 6.0; en-US) AppleWebKit/533.4 (KHTML, like
Gecko) Chrome/5.0.375.127 Safari/533.4"<HTAB>
"host5.example.com"<HTAB>0<CRLF>
#SHA256-hash:<HTAB> 64-hexadecimal-digit hash value <CRLF>Figure 5: CDNI Logging File Example with a Missing Field Value
3.7. Cascaded CDNI Logging Files Example 🎀
Okay bestie, let's look at the cascaded CDN situation with uCDN, dCDN-2, and dCDN-3, as shown in Figure 1 🦋. After dCDN-3 finishes a delivery on behalf of dCDN-2, dCDN-3 adds a matching Logging Record to a CDNI Logging File, and dCDN-2 pulls that file. It's giving Figure 6 below 💅. Real talk, a CDNI Logging File is probably going to have a massive number of Logging Records 📚. So for readability, Figure 6 only shows one. 🙈
#version:<HTAB>cdni/1.0<CRLF>
#UUID:<HTAB>urn:uuid:65718ef-0123-9876-adce4321bcde<CRLF>
#claimed-origin:<HTAB>cdni-logging-entity.dcdn-3.example.com<CRLF>
#record-type:<HTAB>cdni_http_request_v1<CRLF>
#fields:<HTAB>date<HTAB>time<HTAB>time-taken<HTAB>c-groupid<HTAB>
cs-method<HTAB>u-uri<HTAB>protocol<HTAB>
sc-status<HTAB>sc-total-bytes<HTAB>cs(User-Agent)<HTAB>
cs(Referer)<HTAB>s-cached<CRLF>
2013-05-17<HTAB>00:39:09.119<HTAB>14.07<HTAB>US/CA/SFO/94114<HTAB>
GET<HTAB>
http://cdni-dcdn-2.dcdn-3.example.com/video/movie118.mp4<HTAB>
HTTP/1.1<HTAB>200<HTAB>15799210<HTAB>"Mozilla/5.0
(Windows; U; Windows NT 6.0; en-US) AppleWebKit/533.4 (KHTML, like
Gecko) Chrome/5.0.375.127 Safari /533.4"<HTAB>
"host1.example.com"<HTAB>1<CRLF>
#SHA256-hash:<HTAB> 64-hexadecimal-digit hash value <CRLF>Figure 6: Cascaded CDNI Logging File Example (dCDN-3 to dCDN-2)
If dCDN-2 works out, by some means (e.g., via TLS authentication when pulling the CDNI Logging File), who the entity was that it pulled the file from, dCDN-2 can add an established-origin directive to the CDNI Logging, like this 🌸:
#established-origin:<HTAB>cdni-logging-entity.dcdn-3.example.com<CRLF>Next, dCDN-2 (acting as an upstream CDN from dCDN-3's point of view) ingests the CDNI Logging Record for that dCDN-3 delivery into its Collection process (as shown in Figure 2) ✨. This Logging Record can get aggregated with Logging Records that dCDN-2 made locally for its own deliveries 🫶. Picture this: the delivery dCDN-3 did for dCDN-2 was actually redirected to dCDN-2 by uCDN, and then another delivery gets redirected by uCDN to dCDN-2, and dCDN-2 decides to do that one itself 👑. After Filtering and Rectification (as shown in Figure 2), dCDN-2 puts both Logging Records, the one for dCDN-3's delivery and the one for dCDN-2's own delivery, into the next CDNI Logging File it sends to uCDN 🦋. Here's what that file looks like, Figure 7 ⭐.
#version:<HTAB>cdni/1.0<CRLF>
#UUID:<HTAB>urn:uuid:1234567-8fedc-abab-0987654321ff<CRLF>
#claimed-origin:<HTAB>cdni-logging-entity.dcdn-2.example.com<CRLF>
#record-type:<HTAB>cdni_http_request_v1<CRLF>
#fields:<HTAB>date<HTAB>time<HTAB>time-taken<HTAB>c-groupid<HTAB>
cs-method<HTAB>u-uri<HTAB>protocol<HTAB>
sc-status<HTAB>sc-total-bytes<HTAB>cs(User-Agent)<HTAB>
cs(Referer)<HTAB>s-cached<CRLF>
2013-05-17<HTAB>00:39:09.119<HTAB>14.07<HTAB>US/CA/SFO/94114<HTAB>
GET<HTAB>
http://cdni-ucdn.dcdn-2.example.com/video/movie118.mp4<HTAB>
HTTP/1.1<HTAB>200<HTAB>15799210<HTAB>"Mozilla/5.0
(Windows; U; Windows NT 6.0; en-US) AppleWebKit/533.4 (KHTML, like
Gecko) Chrome/5.0.375.127 Safari /533.4"<HTAB>
"host1.example.com"<HTAB>1<CRLF>
2013-05-17<HTAB>01:42:53.437<HTAB>52.879<HTAB>FR/IDF/PAR/75001<HTAB>
GET<HTAB>
http://cdni-ucdn.dcdn-2.example.com/video/picture11.mp4<HTAB>
HTTP/1.0<HTAB>200<HTAB>97234724<HTAB>"Mozilla/5.0
(Windows; U; Windows NT 6.0; en-US) AppleWebKit/533.4 (KHTML, like
Gecko) Chrome/5.0.375.127 Safari /533.4"<HTAB>
"host5.example.com"<HTAB>0<CRLF>
#SHA256-hash:<HTAB> 64-hexadecimal-digit hash value <CRLF>Figure 7: Cascaded CDNI Logging File Example (dCDN-2 to uCDN)
If uCDN works out, by some means (e.g., via TLS authentication when pulling the CDNI Logging File), who it pulled the file from, uCDN can add an established-origin directive to the CDNI Logging, like this 🧚:
#established-origin:<HTAB>cdni-logging-entity.dcdn-2.example.com<CRLF>So in the Figure 7 example, here's the tea ☕:
- The first Logging Record matches the one dCDN-3 sent earlier to dCDN-2. It's for a delivery that uCDN redirected to dCDN-2, and then dCDN-2 redirected it to dCDN-3 💜. The field values in this record are copied from the CDNI Logging Record that dCDN-3 sent to dCDN2, except for the u-uri. That one now follows the URI convention between uCDN and dCDN-2 and makes the delivery look like dCDN-2 did it itself 🌈. This is because dCDN-2 took full responsibility for that delivery, even though it chose to redirect it to dCDN-3, so dCDN-3 is actually the one performing it on dCDN-2's behalf 💅.
- The second Logging Record matches a delivery that uCDN redirected to dCDN-2 and that dCDN-2 performed itself 🍓. The time of this delivery can be a lot more recent than the first record's time 😭. That's because dCDN-2 generated this one locally, while dCDN-3 generated the first one, which then had to be advertised, pulled, and ingested into the dCDN-2 Collection process before it got aggregated with the second record 🔥.
4. Protocol for Exchange of CDNI Logging File after Full Collection ✨
This section lays out a protocol for swapping CDNI Logging Files, as described in Section 3, once the dCDN has fully collected the CDNI Logging File 🎀.
This protocol has two parts:
- a CDNI Logging feed, which lets the dCDN tell the uCDN which CDNI Logging Files that uCDN can pull from the dCDN, plus all the info needed to retrieve each of those files 📣. The CDNI Logging feed is specified in Section 4.1.
- a CDNI Logging File pull mechanism, which lets the uCDN grab a particular CDNI Logging File from the dCDN whenever it's convenient for the uCDN 🦋. The CDNI Logging File pull mechanism is specified in Section 4.2.
An implementation of the CDNI Logging interface on the dCDN side (the entity generating the CDNI Logging File) MUST support the server side of the CDNI Logging feed (as specified in Section 4.1) and the server side of the CDNI Logging pull mechanism (as specified in Section 4.2).
An implementation of the CDNI Logging interface on the uCDN side (the entity consuming the CDNI Logging File) MUST support the client side of the CDNI Logging feed (as specified in Section 4.1) and the client side of the CDNI Logging pull mechanism (as specified in Section 4.2).
4.1. CDNI Logging Feed 📡
The server-side implementation of the CDNI Logging feed MUST produce an Atom feed [RFC4287]. This feed advertises the log files that the client side can retrieve using the CDNI Logging pull mechanism 💖.
4.1.1. Atom Formatting 💅
A CDNI Logging feed MUST be structured as an Archived feed, as defined in [RFC5005], and MUST be formatted in Atom [RFC4287]. Basically, it's a subscription document that gets updated regularly as new CDNI Logging Files show up, and info about older CDNI Logging Files gets moved into archive documents 📚. Once an archive document is created, it is never modified 🔒.
Each CDNI Logging File listed in an Atom feed MUST be described in an atom:entry container element 🌸.
The atom:entry MUST contain an atom:content element whose "src" attribute is a link to the CDNI Logging File and whose "type" attribute is the MIME Media Type indicating that the entry is a CDNI Logging File. This MIME Media Type is defined as "application/cdni" (See [RFC7736]) with the Payload Type (ptype) parameter set to "logging-file" 🎀.
For compatibility with some Atom feed readers, the atom:entry MAY also contain an atom:link entry whose "href" attribute is a link to the CDNI Logging File and whose "type" attribute is the MIME Media Type indicating that the entry is a CDNI Logging File using the "application/cdni" MIME Media Type with the Payload Type (ptype) parameter set to "logging-file" (see [RFC7736]) 🧚.
The URI used in the atom:id of the atom:entry MUST contain the UUID of the CDNI Logging File 🆔.
The atom:updated in the atom:entry MUST indicate the time at which the CDNI Logging File was last updated ⏰.
4.1.2. Updates to Log Files and the Feed 🔄
CDNI Logging Files MUST NOT be modified by the dCDN once published in the CDNI Logging feed 🚫. Not even a little bit, periodt 💀.
How often the subscription feed gets updated, how much time each CDNI Logging File or archive document covers, and how quickly CDNI Logging Files get published are all outside the scope of this document 🙈. They're expected to be agreed upon by the uCDN and dCDN via other means (e.g., human agreement) 🤝.
The server-side implementation MUST be able to set, and SHOULD set, HTTP-cache control headers on the subscription feed to indicate the frequency at which the client side is to poll for updates ⏲️.
The client-side MAY use HTTP-cache control headers (set by the server side) on the subscription feed to determine the frequency at which to poll for updates. The client-side MAY instead, or in addition, use other information to determine when to poll for updates (e.g., a polling frequency that may have been negotiated between the uCDN and dCDN by mechanisms outside the scope of the present document and that is to override the indications provided in the HTTP-cache control headers) 🦋.
How long the dCDN has to keep an archive document around and ready to serve (e.g., a sliding time window) is outside the scope of this document too 🕰️. It's expected to be agreed upon by the uCDN and dCDN via other means (e.g., human agreement) 🫶. The server-side implementation MUST retain, and be ready to serve, any archive document within the agreed retention limits 💜. Outside those agreed limits, the server-side implementation MAY indicate its inability to serve an archive document (e.g., with HTTP status code 404) or MAY refuse to serve it (e.g., with HTTP status code 403 or 410) 🙅♀️.
4.1.3. Redundant Feeds 🌈
The server-side implementation MAY present more than one CDNI Logging feed for redundancy. Each CDNI Logging File MAY be published in more than one feed 👯.
A client-side implementation MAY support such redundant CDNI Logging feeds. If it supports a redundant CDNI Logging feed, the client side can use the UUID of the CDNI Logging File, presented in the atom:id element of the Atom feed, to avoid unnecessarily pulling and storing a given CDNI Logging File more than once 🧠✨.
4.1.4. Example CDNI Logging Feed 🎀
Okay so, Figure 8 shows what the subscription document of a CDNI Logging feed can look like, bestie 💖
<?xml version="1.0" encoding="utf-8"?>
<feed xmlns="http://www.w3.org/2005/Atom">
<title type="text">CDNI Logging Feed</title>
<updated>2013-03-23T14:46:11Z</updated>
<id>urn:uuid:663ae677-40fb-e99a-049d-c5642916b8ce</id>
<link href="https://dcdn.example/logfeeds/ucdn1"
rel="self" type="application/atom+xml" />
<link href="https://dcdn.example/logfeeds/ucdn1"
rel="current" type="application/atom+xml" />
<link href="https://dcdn.example/logfeeds/ucdn1/201303231400"
rel="prev-archive" type="application/atom+xml" />
<generator version="example version 1">CDNI Log Feed
Generator</generator>
<author><name>dcdn.example</name></author>
<entry>
<title type="text">CDNI Logging File for uCDN at
2013-03-23 14:15:00</title>
<id>urn:uuid:12345678-1234-abcd-00aa-01234567abcd</id>
<updated>2013-03-23T14:15:00Z</updated>
<content src="https://dcdn.example/logs/ucdn/
http-requests-20130323141500000000"
type="application/cdni"
ptype="logging-file"/>
<summary>CDNI Logging File for uCDN at
2013-03-23 14:15:00</summary>
</entry>
<entry>
<title type="text">CDNI Logging File for uCDN at
2013-03-23 14:30:00</title>
<id>urn:uuid:87654321-4321-dcba-aa00-dcba7654321</id>
<updated>2013-03-23T14:30:00Z</updated>
<content src="https://dcdn.example/logs/ucdn/
http-requests-20130323143000000000"
type="application/cdni"
ptype="logging-file"/>
<summary>CDNI Logging File for uCDN at
2013-03-23 14:30:00</summary>
</entry>
...
<entry>
...
</entry>
</feed>Figure 8: Example Subscription Document of a CDNI Logging Feed
4.2. CDNI Logging File Pull 🦋
A client-side implementation of the CDNI Logging interface MAY pull, whenever it likes, a CDNI Logging File that the server-side publishes in the CDNI Logging Feed (in the subscription document or an archive document). To do that, the client-side:
- MUST implement HTTP/1.1 ([RFC7230] [RFC7231] [RFC7232] [RFC7233] [RFC7234] [RFC7235]), MAY also support other HTTP versions (e.g., HTTP/2 [RFC7540]), and MAY negotiate which HTTP version is actually used. This lets operators and implementers use newer HTTP versions for shiny new features, while still staying interoperable with systems that only support HTTP/1.1 🌈
- MUST use the URI that was associated with the CDNI Logging File (within the
"src"attribute of the correspondingatom:contentelement) in the CDNI Logging Feed 🔗 - MUST support exchange of CDNI Logging Files with no content encoding applied to the representation
- MUST support exchange of CDNI Logging Files with
"gzip"content encoding (as defined in [RFC7230]) applied to the representation
Note that a client-side implementation of the CDNI Logging interface MAY pull a CDNI Logging File that it has already pulled. Double-pulling is allowed, no judgment 💅
The server-side implementation MUST respond to a valid pull request from a client-side implementation for a CDNI Logging File that the server-side published in the CDNI Logging Feed (in the subscription document or an archive document). The server-side implementation:
- MUST implement HTTP/1.1 to handle the client-side request and MAY also support other HTTP versions (e.g., HTTP/2) 🧚
- MUST include the CDNI Logging File identified by the request URI inside the body of the HTTP response
- MUST support exchange of CDNI Logging Files with no content encoding applied to the representation
- MUST support exchange of CDNI Logging Files with
"gzip"content encoding (as defined in [RFC7231]) applied to the representation
Content negotiation approaches defined in [RFC7231] (e.g., using the Accept-Encoding request-header field or the Content-Encoding entity-header field) MAY be used by the client-side and server-side implementations to agree on the content coding for a particular exchange of a CDNI Logging File. Basically they get to pick the vibe together ✨
Applying compression content encoding (such as "gzip") is expected to help with the impact of exchanging the huge volumes of logging information expected across CDNs. This is expected to be especially useful with HTTP Adaptive Streaming (HAS), which, per the present version of the document, results in a separate CDNI Log Record for each HAS segment delivery in the CDNI Logging File. That's a LOT of records, so compression is giving main character energy 😭
The potential retention limits (e.g., a sliding time window and maximum aggregate file storage quotas) within which the dCDN is to retain, and be ready to serve, a CDNI Logging File previously advertised in the CDNI Logging Feed are outside the scope of the present document. They're expected to be agreed upon by uCDN and dCDN via other means (e.g., human agreement), so go talk to each other 🫶 The server-side implementation MUST retain, and be ready to serve, any CDNI Logging File within the agreed retention limits. Outside these agreed limits, the server-side implementation MAY indicate its inability to serve (e.g., with HTTP status code 404) a CDNI Logging File, or MAY refuse to serve it (e.g., with HTTP status code 403 or 410). Bye file, it's been fun 👋
5. Protocol for Exchange of CDNI Logging File During Collection 🌸
We note that, in addition to the CDNI Logging File exchange protocol specified in Section 4, implementations of the CDNI Logging interface may also support other mechanisms to exchange CDNI Logging Files. In particular, such mechanisms might let the exchange of the CDNI Logging File start before the file is fully collected. This can let CDNI Logging Records get communicated by the dCDN to the uCDN as the dCDN gathers them, without having to wait until all the CDNI Logging Records of the same logging period are collected in the corresponding CDNI Logging File. This approach is commonly referred to as the "tailing" of the file, which is such a vibe 🦋
Such an approach could be used, for example, to exchange logging information with a significantly reduced time-lag (e.g., sub-minute or sub-second) between when the event occurred in the dCDN and when the corresponding CDNI Logging Record is made available to the uCDN. This can satisfy log-consuming applications that need extremely fresh logging information, such as near-real-time content delivery monitoring 🔥 Such mechanisms are for further study and are outside the scope of this document, so we'll save that drama for later 🙈
6. IANA Considerations 📋
6.1. CDNI Logging Directive Names Registry 🍓
IANA has created a new "CDNI Logging Directive Names" subregistry under the "Content Delivery Networks Interconnection (CDNI) Parameters" registry.
The initial contents of the "CDNI Logging Directives" registry comprise the names of the directives specified in Section 3.3 of the present document, and they look like this:
+------------------------------+-----------+
| Directive Name | Reference |
+------------------------------+-----------+
| version | RFC 7937 |
| UUID | RFC 7937 |
| claimed-origin | RFC 7937 |
| established-origin | RFC 7937 |
| remark | RFC 7937 |
| record-type | RFC 7937 |
| fields | RFC 7937 |
| SHA256-hash | RFC 7937 |
+------------------------------+-----------+Figure 9: CDNI Logging Directive Names Registry
Within the registry, names are to be allocated by IANA according to the "Specification Required" policy specified in [RFC5226]. Directive names are to be allocated by IANA with a format of NAMEFORMAT (see Section 3.1). All directive names defined in the Logging File are case-insensitive as per the basic ABNF ([RFC5234]).
Each specification that defines a new CDNI Logging directive needs to contain a description for the new directive with the same set of information as provided in Section 3.3 (i.e., format, directive value, and occurrence). Pinky promise 🤞
6.2. CDNI Logging File version Registry 🌈
IANA has created a new "CDNI Logging File version" subregistry under the "Content Delivery Networks Interconnection (CDNI) Parameters" registry.
The initial contents of the "CDNI Logging File version" registry comprise the value "cdni/1.0" specified in Section 3.3 of the present document, and they look like this:
+-----------------+-----------+----------------------------------+
| version | Reference | Description |
+-----------------+-----------+----------------------------------+
| cdni/1.0 | RFC 7937 | CDNI Logging File version 1.0 |
| | | as specified in RFC 7937 |
+-----------------+-----------+----------------------------------+Figure 10: CDNI Logging File version Registry
Within the registry, version values are to be allocated by IANA according to the "Specification Required" policy specified in [RFC5226]. Version values are to be allocated by IANA with a format of NAMEFORMAT (see Section 3.1). All version values defined in the Logging File are case-insensitive as per the basic ABNF ([RFC5234]).
6.3. CDNI Logging record-types Registry ✨
IANA has created a new "CDNI Logging record-types" subregistry under the "Content Delivery Networks Interconnection (CDNI) Parameters" registry.
The initial contents of the "CDNI Logging record-types" registry comprise the names of the CDNI Logging record-types specified in Section 3.4 of the present document, and they look like this:
+----------------------+-----------+---------------------------------+
| record-types | Reference | Description |
+----------------------+-----------+---------------------------------+
| cdni_http_request_v1 | RFC 7937 | CDNI Logging Record version 1 |
| | | for content delivery using HTTP |
+----------------------+-----------+---------------------------------+Figure 11: CDNI Logging record-types Registry
Within the registry, record-types are to be allocated by IANA according to the "Specification Required" policy specified in [RFC5226]. Record-types are to be allocated by IANA with a format of NAMEFORMAT (see Section 3.1). All record-types defined in the Logging File are case-insensitive as per the basic ABNF ([RFC5234]).
Each specification that defines a new record-type needs to contain a description for the new record-type with the same set of information as provided in Section 3.4.1. This includes:
- A list of all the CDNI Logging fields that can appear in a CDNI Logging Record of the new record-type
- For all these fields: a specification of the occurrence for each Field in the new record-type
- For every newly defined Field, i.e., for every Field that results in a registration in the "CDNI Logging Field Names" registry (Section 6.4): a specification of the field name, format, and field value
6.4. CDNI Logging Field Names Registry ✨
okay bestie, IANA made a brand new "CDNI Logging Field Names" subregistry 🗂️ tucked under the "Content Delivery Networks Interconnection (CDNI) Parameters" registry. it's giving organized 💅
this registry is meant to be shared by the currently defined record-type (cdni_http_request_v1) and any other CDNI Logging record-types that get defined in separate specs 🌈 when another record-type uses a field from here, it has to use the exact semantics and format from the document that registered that field (the one listed in the Reference column) 🎯 if a record-type needs a field whose semantics or format is not strictly identical, that field gets registered again under a different field name 🙅♀️ and yes, a shared field can be used with different occurrence rules 💖
the initial contents of the "CDNI Logging Fields Names" registry are the field names from Section 3.4 of this document, and they look like this:
+------------------------------------------+-----------+
| Field Name | Reference |
+------------------------------------------+-----------+
| date | RFC 7937 |
| time | RFC 7937 |
| time-taken | RFC 7937 |
| c-groupid | RFC 7937 |
| s-ip | RFC 7937 |
| s-hostname | RFC 7937 |
| s-port | RFC 7937 |
| cs-method | RFC 7937 |
| cs-uri | RFC 7937 |
| u-uri | RFC 7937 |
| protocol | RFC 7937 |
| sc-status | RFC 7937 |
| sc-total-bytes | RFC 7937 |
| sc-entity-bytes | RFC 7937 |
| cs(insert_HTTP_header_name_here) | RFC 7937 |
| sc(insert_HTTP_header_name_here) | RFC 7937 |
| s-ccid | RFC 7937 |
| s-sid | RFC 7937 |
| s-cached | RFC 7937 |
+------------------------------------------+-----------+Figure 12: CDNI Logging Field Names Registry
new names inside the registry get handed out by IANA under the "Specification Required" policy from [RFC5226] 📋 field names have to be in the NHTABSTRING format (see Section 3.1) 🧵 and every field name in the Logging File is case-insensitive, per the basic ABNF in [RFC5234] 🔤 no cap on the vibes, just on the letters 🫶
6.5. CDNI Logging Payload Type 🎀
IANA registered a new Payload Type in the "CDNI Payload Types" registry 🍓 it's for use with the application/cdni MIME media type, and here's the entry:
+----------------------+---------------+
| Payload Type | Specification |
+----------------------+---------------+
| logging-file | RFC 7937] |
+----------------------+---------------+Figure 13: CDNI Logging Payload Type
the whole point of the logging-file payload type is to tell CDNI Logging Files apart from other CDNI messages 🧚 the details:
- Interface:
LI - Encoding: See Section 3.2, Section 3.3, and Section 3.4
7. Security Considerations 🔐
okay bestie, this part is SERIOUS 😭 not dramatic, just important, so pay attention 🫶
7.1. Authentication, Authorization, Confidentiality, and Integrity Protection 🔒
okay so an implementation of the CDNI Logging interface MUST support TLS transport for the CDNI Logging feed (Section 4.1) and the CDNI Logging File pull (Section 4.2), following [RFC2818] and [RFC7230] 💜
TLS MUST be used by the server side and the client side of the CDNI Logging feed, and also by the server side and the client side of the CDNI Logging File pull mechanism. that includes authenticating the remote end 🙌 the one exception is when there are other ways to keep the info exchanged over the LI interface secure, like an IPsec tunnel between the two CDNs, or a physically secured internal network between two CDNs owned by the same corporate entity 🏢✨
using TLS for the CDNI Logging feed and the CDNI Logging File pull gives you a few things 🎀
- the dCDN and uCDN can authenticate each other with TLS client auth and TLS server auth 🪪
and once they've mutually authenticated, it also gives you:
- the dCDN and uCDN can authorize each other, so they know they're sending or receiving CDNI Logging Files with an authorized CDN 👑
- the CDNI Logging information gets sent with confidentiality 🤫
- the integrity of the CDNI Logging information stays protected during the exchange 🛡️
When TLS is used, the general TLS usage guidance in [RFC7525] MUST be followed. this one's non-negotiable, bestie 💀
the SHA256-hash directive inside the CDNI Logging File adds integrity protection too, but this one is aimed at corruption that could happen while the file is generated, stored, or exchanged 🧊 it doesn't fix corrupted info. what it does is let you detect corruption, so you can trigger corrective actions, like tossing out the bad data and trying to get it again 🔁 BUT, and this is a big but 🚨, the SHA256-hash does NOT protect against a third party tampering with things, because that third party could just recalculate and update the hash after messing with the data 😤 protecting against third-party tampering, when the CDNI Logging File goes over the CDN Logging interface, is done through TLS, like we talked about above 💖
7.2. Denial of Service 🛡️
this document doesn't define a specific mechanism to stop Denial-of-Service (DoS) attacks on the Logging interface 🙈 the good news is that the CDNI Logging feed and CDNI Logging pull endpoints are normally only accessed by a very small number of valid remote endpoints, so the usual DoS protections like firewalling or Virtual Private Networks (VPNs) can easily cover them 🧱
protecting dCDN Surrogates against spoofed delivery requests is outside the scope of the CDNI Logging interface 🚫
7.3. Privacy 🕵️♀️
okay so CDNs can collect really detailed info about the downloads end users make 👀 a dCDN is expected to gather that info into CDNI Logging Files, which then get sent to a uCDN 📦
having detailed CDNI Logging information known to the dCDN isn't really a privacy concern on its own, since the dCDN already knows everything it logged, because it generated the info in the first place 🤷♀️
sending detailed CDNI Logging information over the HTTP-based CDNI Logging interface isn't a particular privacy concern either, because it's protected by the usual privacy protections like TLS 🔐
when HTTP redirection is used between the uCDN and the dCDN, making detailed CDNI Logging information known to the uCDN isn't a particular privacy concern 💅 the uCDN is already exposed, at request redirection time, to most of what shows up in CDNI Logging information (like the end-user IP address, the URL, and the HTTP headers) 👁️
when DNS redirection is used between the uCDN and the dCDN, there are cases where sharing detailed CDNI Logging information with the uCDN is no privacy concern at all 🫧 for example, where (1) the uCDN has the authority (with respect to the CSP) and control over how requests get delivered, including whether a dCDN or the uCDN itself serves them, so the uCDN is entitled to all the detailed info about those deliveries, and (2) there's no legal reason to restrict the uCDN's access to all of that info ⚖️
flip it, though 🙃 when DNS redirection is used between the uCDN and the dCDN, there are cases where sharing detailed CDNI Logging information with the uCDN could be a privacy concern 😬 for example, the uCDN could be in a different jurisdiction from the dCDN, which means there are legal reasons to restrict the uCDN's access to all the detailed info about the deliveries 🌍 in that case, the privacy concerns can be handled when the uCDN and dCDN agree on which fields go inside the CDNI Logging Files and which privacy protection mechanism to use, as discussed in the definition of the c-groupid field in Section 3.4.1 🧩
another privacy worry: huge volumes of detailed info about content delivery to users, which might be traceable back to individual users, can pile up in CDNI Logging Files 📚 these files are high-value targets, probably concentrated in a fairly centralized system (though the CDNI Logging architecture doesn't require any particular level of centralization or distribution), and they're at risk of data exfiltration 🏴☠️ the ways that exfiltration could happen are outside the scope of the CDNI Logging interface itself, like a corrupted employee or a corrupted logging storage system 😱 this privacy concern calls for some protection 🫶
collecting that much information into CDNI Logging Files brings up end users' privacy protection concerns too, and the mechanisms for addressing them are in the definition of the c-groupid field in Section 3.4.1 🎀
using mutually authenticated TLS to set up a secure session for the CDNI Logging feed and CDNI Logging pull, as discussed in Section 7.1, gives you confidentiality while the logging info is in transit, and it stops anyone other than the authorized uCDN from getting access to it 🔒✨
also, the query string part of the URL that can show up in the cs-uri and u-uri fields of CDNI Logging Files, and the HTTP cookies ([RFC6265]) that can show up in the cs(<HTTP-header-name>) field of CDNI Logging Files, may contain personal info or info that can be used to figure out personal info 🍪 where that's a concern, the CDNI Logging interface spec lets the dCDN leave out cs-uri and include a u-uri that removes or hides the sensitive part of the query string 🙈 it also lets the dCDN leave out the cs(<HTTP-header-name>) fields for HTTP headers tied to cookies 💜
8. References 📚
8.1. Normative References
okay bestie, these are the must-read docs the spec leans on so hard it literally can't function without them 📚💖 no cap, the whole thing is built on top of them ✨
[AES] NIST, "Advanced Encryption Standard (AES)", National
Institute of Standards and Technology FIPS 197, November
2001, <http://csrc.nist.gov/publications/fips/fips197/
fips-197.pdf>.
[GCM] NIST, "Recommendation for Block Cipher Modes of Operation:
Galois/Counter Mode (GCM) and GMAC", National Institute of
Standards and Technology SP 800-38D,
DOI 10.6028/NIST.SP.800-38D, November 2007,
<http://csrc.nist.gov/publications/nistpubs/800-38D/
SP-800-38D.pdf>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC3339] Klyne, G. and C. Newman, "Date and Time on the Internet:
Timestamps", RFC 3339, DOI 10.17487/RFC3339, July 2002,
<http://www.rfc-editor.org/info/rfc3339>.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, DOI 10.17487/RFC3986, January 2005,
<http://www.rfc-editor.org/info/rfc3986>.
[RFC4122] Leach, P., Mealling, M., and R. Salz, "A Universally
Unique IDentifier (UUID) URN Namespace", RFC 4122,
DOI 10.17487/RFC4122, July 2005,
<http://www.rfc-editor.org/info/rfc4122>.
[RFC4287] Nottingham, M., Ed. and R. Sayre, Ed., "The Atom
Syndication Format", RFC 4287, DOI 10.17487/RFC4287,
December 2005, <http://www.rfc-editor.org/info/rfc4287>.
[RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data
Encodings", RFC 4648, DOI 10.17487/RFC4648, October 2006,
<http://www.rfc-editor.org/info/rfc4648>.
[RFC5005] Nottingham, M., "Feed Paging and Archiving", RFC 5005,
DOI 10.17487/RFC5005, September 2007,
<http://www.rfc-editor.org/info/rfc5005>.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
DOI 10.17487/RFC5226, May 2008,
<http://www.rfc-editor.org/info/rfc5226>.
[RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", STD 68, RFC 5234,
DOI 10.17487/RFC5234, January 2008,
<http://www.rfc-editor.org/info/rfc5234>.
[RFC7230] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
Protocol (HTTP/1.1): Message Syntax and Routing",
RFC 7230, DOI 10.17487/RFC7230, June 2014,
<http://www.rfc-editor.org/info/rfc7230>.
[RFC7231] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
Protocol (HTTP/1.1): Semantics and Content", RFC 7231,
DOI 10.17487/RFC7231, June 2014,
<http://www.rfc-editor.org/info/rfc7231>.
[RFC7232] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
Protocol (HTTP/1.1): Conditional Requests", RFC 7232,
DOI 10.17487/RFC7232, June 2014,
<http://www.rfc-editor.org/info/rfc7232>.
[RFC7233] Fielding, R., Ed., Lafon, Y., Ed., and J. Reschke, Ed.,
"Hypertext Transfer Protocol (HTTP/1.1): Range Requests",
RFC 7233, DOI 10.17487/RFC7233, June 2014,
<http://www.rfc-editor.org/info/rfc7233>.
[RFC7234] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke,
Ed., "Hypertext Transfer Protocol (HTTP/1.1): Caching",
RFC 7234, DOI 10.17487/RFC7234, June 2014,
<http://www.rfc-editor.org/info/rfc7234>.
[RFC7235] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
Protocol (HTTP/1.1): Authentication", RFC 7235,
DOI 10.17487/RFC7235, June 2014,
<http://www.rfc-editor.org/info/rfc7235>.
[RFC7525] Sheffer, Y., Holz, R., and P. Saint-Andre,
"Recommendations for Secure Use of Transport Layer
Security (TLS) and Datagram Transport Layer Security
(DTLS)", BCP 195, RFC 7525, DOI 10.17487/RFC7525, May
2015, <http://www.rfc-editor.org/info/rfc7525>.
[RFC7540] Belshe, M., Peon, R., and M. Thomson, Ed., "Hypertext
Transfer Protocol Version 2 (HTTP/2)", RFC 7540,
DOI 10.17487/RFC7540, May 2015,
<http://www.rfc-editor.org/info/rfc7540>.
[SHA-3] NIST, "SHA-3 Standard: Permutation-Based Hash and
Extendable-Output Functions", National Institute of
Standards and Technology FIPS 202,
DOI 10.6028/NIST.FIPS.202, August 2015,
<http://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.202.pdf>.8.2. Informative References
these ones are the extra reading 🧚 handy for background, but the spec doesn't need them to work, so no panic if you skip 'em 🌸
[ATOMPUB] Snell, J., "Atom Link Extensions", Work in Progress,
draft-snell-atompub-link-extensions-09, June 2012.
[CDNI-META]
Niven-Jenkins, B., Murray, R., Caulfield, M., and K. Ma,
"CDN Interconnection Metadata", Work in Progress,
draft-ietf-cdni-metadata-20, August 2016.
[CHAR_SET] IANA, "Character Sets",
<http://www.iana.org/assignments/character-sets>.
[ELF] Phillip M. Hallam-Baker, and Brian Behlendorf, "Extended
Log File Format", W3C Working Draft, WD-logfile-960323,
<http://www.w3.org/TR/WD-logfile.html>.
[RFC1945] Berners-Lee, T., Fielding, R., and H. Frystyk, "Hypertext
Transfer Protocol -- HTTP/1.0", RFC 1945,
DOI 10.17487/RFC1945, May 1996,
<http://www.rfc-editor.org/info/rfc1945>.
[RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818,
DOI 10.17487/RFC2818, May 2000,
<http://www.rfc-editor.org/info/rfc2818>.
[RFC5869] Krawczyk, H. and P. Eronen, "HMAC-based Extract-and-Expand
Key Derivation Function (HKDF)", RFC 5869,
DOI 10.17487/RFC5869, May 2010,
<http://www.rfc-editor.org/info/rfc5869>.
[RFC6234] Eastlake 3rd, D. and T. Hansen, "US Secure Hash Algorithms
(SHA and SHA-based HMAC and HKDF)", RFC 6234,
DOI 10.17487/RFC6234, May 2011,
<http://www.rfc-editor.org/info/rfc6234>.
[RFC6265] Barth, A., "HTTP State Management Mechanism", RFC 6265,
DOI 10.17487/RFC6265, April 2011,
<http://www.rfc-editor.org/info/rfc6265>.
[RFC6707] Niven-Jenkins, B., Le Faucheur, F., and N. Bitar, "Content
Distribution Network Interconnection (CDNI) Problem
Statement", RFC 6707, DOI 10.17487/RFC6707, September
2012, <http://www.rfc-editor.org/info/rfc6707>.
[RFC6770] Bertrand, G., Ed., Stephan, E., Burbridge, T., Eardley,
P., Ma, K., and G. Watson, "Use Cases for Content Delivery
Network Interconnection", RFC 6770, DOI 10.17487/RFC6770,
November 2012, <http://www.rfc-editor.org/info/rfc6770>.
[RFC6983] van Brandenburg, R., van Deventer, O., Le Faucheur, F.,
and K. Leung, "Models for HTTP-Adaptive-Streaming-Aware
Content Distribution Network Interconnection (CDNI)",
RFC 6983, DOI 10.17487/RFC6983, July 2013,
<http://www.rfc-editor.org/info/rfc6983>.
[RFC7336] Peterson, L., Davie, B., and R. van Brandenburg, Ed.,
"Framework for Content Distribution Network
Interconnection (CDNI)", RFC 7336, DOI 10.17487/RFC7336,
August 2014, <http://www.rfc-editor.org/info/rfc7336>.
[RFC7337] Leung, K., Ed. and Y. Lee, Ed., "Content Distribution
Network Interconnection (CDNI) Requirements", RFC 7337,
DOI 10.17487/RFC7337, August 2014,
<http://www.rfc-editor.org/info/rfc7337>.
[RFC7736] Ma, K., "Content Delivery Network Interconnection (CDNI)
Media Type Registration", RFC 7736, DOI 10.17487/RFC7736,
December 2015, <http://www.rfc-editor.org/info/rfc7736>.
[TLS-1.3] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", Work in Progress, draft-ietf-tls-tls13-15,
August 2016.Acknowledgments
big thank-yous time 🫶🎀
This document borrows from the W3C Extended Log Format [ELF].
Rob Murray significantly contributed into the text of Section 4.1. The authors thank Ben Niven-Jenkins, Kevin Ma, David Mandelberg, and Ray van Brandenburg for their ongoing input. 💜
Brian Trammel and Rich Salz made significant contributions into making this interface privacy-friendly. main character privacy energy 🌈✨
Finally, we also thank Sebastien Cubaud, Pawel Grochocki, Christian Jacquenet, Yannick Le Louedec, Anne Marrec, Emile Stephan, Fabio Costa, Sara Oueslati, Yvan Massot, Renaud Edel, Joel Favier, and the contributors of the EU FP7 OCEAN project for their input in the early draft versions of this document. 🍓🦋
Authors' Addresses
the squad behind this one 👑💅
Francois Le Faucheur (editor)
France
Phone: +33 6 19 98 50 90
Email: flefauch@gmail.com
Gilles Bertrand (editor)
Phone: +41 76 675 91 44
Email: gilbertrand@gmail.com
Iuniana Oprescu (editor)
France
Email: iuniana.oprescu@gmail.com
Roy Peterkofsky
Google Inc.
345 Spear St, 4th Floor
San Francisco CA 94105
United States of America
Email: peterkofsky@google.com📦 where this page comes from
- ietf: rfc7937 2016-08
- 💖 girlified by claude-haiku-5-5 on : a language model's rewrite of the original, under its terms