From: "Tom Lane" <t...@sss.pgh.pa.us>
"MauMau" <maumau...@gmail.com> writes:
The bad thing is that pg_ctl continues to wait until the specified
duration
passes, even if postgres fails to start. For example, it is naturally
desirable for pg_ctl to terminate when postgresql.conf contains a syntax
error.
Hmm, I thought we'd fixed this in the last go-round of pg_ctl wait
revisions, but testing proves it does not work desirably in HEAD:
not only does pg_ctl wait till its timeout elapses, but it then reports
"server started" even though the server didn't start. That's clearly a
bug :-(
I think your proposal of a pipe-based solution might be overkill though.
Seems like it would be sufficient for pg_ctl to give up if it doesn't
see the postmaster.pid file present within a couple of seconds of
postmaster startup. I don't really want to add logic to the postmaster
to have the sort of reporting protocol you propose, because not
everybody uses pg_ctl to start the postmaster. In any case, we need a
fix in 9.1 ...
Yes, I was a bit afraid the pipe-based fix might be overkill, too, so I was
wondering if there might be a more easy solution.
"server started"... I missed it. That's certainly a bug, as you say.
I was also considering the postmaster.pid-based solution exactly as you
suggest, but that has a problem -- how many seconds do we assume for "a
couple of seconds"? If the system load is temporarily so high that
postmaster takes many seconds to create postmaster.pid, pg_ctl mistakenly
thinks that postmaster failed to start. I know this is a hypothetical rare
case. I don't like touching the postmaster logic and complicating it, but
logical correctness needs to come first (Japanese users are very severe).
Another problem with postmaster.pid-based solution happens after postmaster
crashes. When postmaster crashes, postmaster.pid is left. If the pid in
postmaster.pid is allocated to some non-postgres process and that process
remains, pg_ctl misjudges that postmaster is starting up, and waits for long
time.
Regards
MauMau
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