LAT_RPC(8)

📦 version 3.0-a9, in debian bookworm, debian trixie, ubuntu jammy, ubuntu noble, ubuntu questing, ubuntu resolute, ubuntu stonking

🌸 LAT_RPC 💅

okay bestie, so this is lat_rpc(8) — it lives in the LMBENCH manual, and it's about to measure how fast two processes can gossip with each other over Sun RPC. no cap. 🫶

✨ NAME ✨

lat_rpc — measure interprocess communication latency via Sun RPC 🔥

🎀 SYNOPSIS 🎀

lat_rpc -s
lat_rpc [ -P <parallelism> ] [ -W <warmups> ] [ -N <repetitions> ] [ -p tcp|udp ] hostname [ udp|tcp ]
lat_rpc -S hostname

🦋 DESCRIPTION 🦋

okay so lat_rpc is a client/server situation — one program, two moods — and its whole personality is measuring interprocess communication latencies. the benchmark passes a token back and forth between the two processes. and if that sounds like a game, it literally is one: this kind of benchmark is frequently called a "hot potato" benchmark. 🥔✨

and the way that it does nothing else? no other work is done in the processes. that's the entire job. iconic honestly.

the point of all this is that you can compare it against the TCP and UDP forms of the same benchmark to accurately see the cost of using RPC versus the cost of using plain old TCP or UDP sockets. and ngl, it's worth noting that the RPC form is passing back and forth a single byte, not some long complicated record. one byte!! the audacity of it. 💀

lat_rpc has three forms of usage:

  • as a server (-s) 👑
  • as a client (lat_rpc localhost) 💖
  • as a shutdown (lat_rpc -S localhost) 🚪

the client form may specify the protocol over which the RPCs are performed. the default is to measure performance for both udp and tcp. so you get both vibes unless you ask for one.

🌈 OUTPUT 🌈

the reported time is in microseconds per round trip and it includes the total time, i.e., the context switching overhead is includeded. (yes bestie, that typo is canon, we don't fix the canon 💅)

output format is like so:

RPC/udp latency using localhost: 1344 microseconds
RPC/tcp latency using localhost: 2089 microseconds

💖 ACKNOWLEDGEMENT 💖

funding for the development of this tool was provided by Sun Microsystems Computer Corporation. we love a sponsor moment. 🫶✨

🌸 SEE ALSO 🌸

👑 AUTHOR 👑

Carl Staelin and Larry McVoy

comments, suggestions, and bug reports are always welcome. fr fr, they want to hear from you. 💌

no notes, just vibes: (c)1994 Larry McVoy, $Date$, and this whole thing is served fresh from the LMBENCH manual. 🎀 slay, go measure some latency bestie 💅🦋
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