From fe11e75d913ac320f11ac2250c94fa58b118b2e1 Mon Sep 17 00:00:00 2001 From: Jelte Fennema-Nio Date: Tue, 11 Feb 2025 22:04:44 +0100 Subject: [PATCH v3 1/3] Bump pgbench soft open file limit (RLIMIT_NOFILE) to hard limit The default open file limit of 1024 is extremely low, given modern resources and kernel architectures. The reason that this hasn't changed is because doing so would break legacy programs that use the select(2) system call in hard to debug ways. So instead programs that want to opt-in to a higher open file limit are expected to bump their soft limit to their hard limit on startup. Details on this are very well explained in a blogpost by the systemd author[1]. This starts bumping pgbench its soft open file limit to the hard open file limit. This makes sure users are not told to change their ulimit, and then retry. Instead we now do that for them automatically. [1]: https://0pointer.net/blog/file-descriptor-limits.html --- src/bin/pgbench/pgbench.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/src/bin/pgbench/pgbench.c b/src/bin/pgbench/pgbench.c index 5e1fcf59c61..8f53bf50ab1 100644 --- a/src/bin/pgbench/pgbench.c +++ b/src/bin/pgbench/pgbench.c @@ -6815,13 +6815,26 @@ main(int argc, char **argv) #ifdef HAVE_GETRLIMIT if (getrlimit(RLIMIT_NOFILE, &rlim) == -1) pg_fatal("getrlimit failed: %m"); - if (rlim.rlim_cur < nclients + 3) + + if (rlim.rlim_max < nclients + 3) { pg_log_error("need at least %d open files, but system limit is %ld", - nclients + 3, (long) rlim.rlim_cur); + nclients + 3, (long) rlim.rlim_max); pg_log_error_hint("Reduce number of clients, or use limit/ulimit to increase the system limit."); exit(1); } + + if (rlim.rlim_cur < nclients + 3) + { + rlim.rlim_cur = nclients + 3; + if (setrlimit(RLIMIT_NOFILE, &rlim) == -1) + { + pg_log_error("need at least %d open files, but couldn't raise the limit", + nclients + 3); + pg_log_error_hint("Reduce number of clients, or use limit/ulimit to increase the system limit."); + exit(1); + } + } #endif /* HAVE_GETRLIMIT */ break; case 'C': base-commit: c407d5426b877b41be87f9e679e321bb2c42e47d -- 2.43.0