LTPCLOCK(1)

📦 version 3.2.1, in ubuntu jammy

👑 LTPCLOCK(1) — the LTP executables era 💅

okay bestie, sit down, hydrate, and let me tell you about ltpclock — the LTP daemon task for managing scheduled events. yes she's a daemon task, yes she's managing scheduled events, and yes she is doing it in the background like the lowkey main character she is 🫶

✨ NAME ✨

ltpclock — LTP daemon task for managing scheduled events. that's it, that's the job, and she eats every single time 💖

🌸 SYNOPSIS 🌸

ltpclock

no flags. no args. no notes. she just is ✨

🦋 DESCRIPTION 🦋

ltpclock is a background "daemon" task that periodically performs scheduled LTP activities. it's giving "i work behind the scenes and you don't even notice me" energy 😌

she gets spawned automatically by ltpadmin in response to the 's' command — that's the one that starts operation of the LTP protocol — and ltpadmin terminates her in response to an 'x' (STOP) command. so basically ltpadmin is her manager and honestly? fine. slay. 💅

⏰ the once-per-second situation

once per second, ltpclock takes the following action, and bestie it is a lot:

  • first she manages the current state of all links ("spans"). in particular, she checks the age of the currently buffered session block for each span, and if that age exceeds the span's configured aggregation time limit, she gives the "buffer full" semaphore for that span — which kicks off block segmentation and transmission by ltpmeter 🔥
  • and while she's doing all that, she also infers link state changes ("link cues") from data rate changes as noted in the RFX database by rfxclock. let me break those down because there are four of them and they all matter:
    1. if the rate of transmission to a neighbor was zero but is now non-zero, then transmission to that neighbor is unblocked. the applicable "buffer empty" semaphore is given if no outbound block is being constructed (which enables the start of a new transmission session), and the "segments ready" semaphore is given if the outbound segment queue is non-empty (which enables transmission of segments by the link service output task) 🌈
    2. if the rate of transmission to a neighbor was non-zero but is now zero, then transmission to that neighbor is blocked — i.e., the semaphores triggering transmission will no longer be given. she said "we're closed" 🚫
    3. if the imputed rate of transmission from a neighbor was non-zero but is now zero, then all timers affecting segment retransmission to that neighbor are suspended. this has the effect of extending the interval of each affected timer by the length of time that the timers remain suspended. so like, the clock keeps running but the timer's on pause, iykyk ⏸️
    4. if the imputed rate of transmission from a neighbor was zero but is now non-zero, then all timers affecting segment retransmission to that neighbor are resumed. welcome back, besties ▶️
  • then ltpclock retransmits all unacknowledged checkpoint segments, report segments, and cancellation segments whose computed timeout intervals have expired. she's cleaning up after everybody, as usual 😭

💀 EXIT STATUS 💀

  • "0" — ltpclock terminated, for reasons noted in the ion.log file. if this termination was not commanded, investigate and solve the problem identified in the log file and use ltpadmin to restart ltpclock. not me getting ghosted by my own daemon 🙈
  • "1" — ltpclock was unable to attach to LTP protocol operations, probably because ltpadmin has not yet been run. she showed up to the party and the venue wasn't even open 💔

🎀 FILES 🎀

no configuration files are needed. she comes as she is, no cap 🫶

🧚 ENVIRONMENT 🧚

no environment variables apply. she's not reading your .bashrc, she's not reading your env, she's just vibing ⭐

🔥 DIAGNOSTICS 🔥

the following diagnostics may be issued to the ion.log log file — and if you see any of these, bestie, go read the log, fr fr:

  • ltpclock can't initialize LTP. — ltpadmin has not yet initialized LTP protocol operations. like, at all. zero. nada. 💀
  • Can't dispatch events. — an unrecoverable database error was encountered. ltpclock terminates. she's done, she's out, she's leaving the group chat 😭
  • Can't manage links. — an unrecoverable database error was encountered. ltpclock terminates. same energy, different function 🫠

🍓 BUGS 🍓

report bugs to <ion-bugs@korgano.eecs.ohiou.edu>. tell them everything. be dramatic. it helps 💜

🌈 SEE ALSO 🌈

her whole friend group, basically 👑

and that's the whole page, bestie — ltpclock, from the LTP executables collection, running under perl v5.24.1, dated 2016-07-07. she's been serving since 2016 and she's never missed a beat. periodt. 💅✨

📦 where this page comes from