On 1/29/26 12:29, [email protected] wrote:
In software I have developed separately, I have noticed that most systems will
periodically delete files within the temporary directory hierarchy that have
not been accessed recently, and that includes lock files for long running
processes. I have never noticed the lock file associated with a postgreSQL
socket be missing though.
Does PostgreSQL periodically touch the lock file so it won’t be deleted?
Alternatively, does PostgreSQL simply re-create the lock file if it has been
deleted? I know the documentation says to never “manually”’delete one of those
lock files.
From here at ~line 1781:
https://github.com/postgres/postgres/blob/master/src/backend/postmaster/postmaster.c
/*
* Once a minute, verify that postmaster.pid hasn't been
removed or
* overwritten. If it has, we force a shutdown. This avoids
having
* postmasters and child processes hanging around after their
database
* is gone, and maybe causing problems if a new database
cluster is
* created in the same place. It also provides some protection
* against a DBA foolishly removing postmaster.pid and manually
* starting a new postmaster. Data corruption is likely to
ensue from
* that anyway, but we can minimize the damage by aborting ASAP.
*/
if (now - last_lockfile_recheck_time >= 1 * SECS_PER_MINUTE)
{
if (!RecheckDataDirLockFile())
{
ereport(LOG,
(errmsg("performing immediate shutdown because data directory lock
file is invalid")));
kill(MyProcPid, SIGQUIT);
}
last_lockfile_recheck_time = now;
}
--
Adrian Klaver
[email protected]
