lltop | Lustre load monitor with batch scheduler integration

lltop is a C library. lltop has no bugs, it has no vulnerabilities, it has a Strong Copyleft License and it has low support. You can download it from GitHub.

lltop[0] is a command line utility which gathers i/o statistics from lustre[1] filesystem servers, along with job assignment data from cluster batch schedulers, to give a job-by-job accounting of filesystem load. under typical usage, lltop is invoked with the name of a filesystem, runs for a configurable interval (10 seconds say), and outputs a table summarizing i/o and rpc loads indexed by job identifier; for example:. $ lltop work job wr_mb rd_mb reqs owner workdir 12101 15925 67630 133694 jfourier /work/jfourier/fftw_run 10322 2254 1027 2504 claude /work/claude/viscous-flow-08 13007 756 21024 10007 ludwig /work/ludwig/boltzeq.mvapich2 ... normally, lltop is run in response to observations of excessive load on file servers or degraded filesystem performance, and is used to assist system administrators in identifying jobs (and users) with problematic i/o patterns. a potential secondary use is to determine the i/o profiles of applications running at scale. lltop is designed to run as a point and shoot diagnostic utility, and is not a replacement for continuous monitoring tools such as lmt[2] or collectl[3]. lltop has two executable components, lltop itself, and lltop-serv. lltop is usually run directly and given the name of a filesystem to query. from the filesystem name, it derives a list of servers (mdss and osss), and for each it forks and execs ssh to run a copy of lltop-serv on the