Re: PostgreSQL hanging on new connections?

On Mon, 2010-11-29 at 15:57 -0500, Vick Khera wrote:
> On Mon, Nov 29, 2010 at 1:23 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> > hubert depesz lubaczewski <depesz(at)depesz(dot)com> writes:
> >> straced postmaster when the problem was happening, and I was opening new
> >> connections. strace looks like this:
> >> [ backend hangs on semop immediately after reading global/pg_database ]
> >
> > It looks like something had exclusive lock on the database that new
> > connections wanted to connect to. AFAICS the only action in 8.3 that
> > would do that would be a DROP DATABASE or RENAME DATABASE. What was
> > that other session doing?
>
> Every once in a while when I connect to my big DB it feels like it
> stalls the connection for a few seconds. I have no idea what causes
> it, but it does feel like it has to do with the load. The load is not
> all that high relative to what my box can handle. It doesn't happen
> often enough for me to track it down, though. It instinct is that it
> is waiting on a lock, but clearly there is no rename/drop happening on
> my main db else i'd be out of business :-) I too run 8.3 as primary
> right now... testing 9.0 for deployment soon-ish.

Initiating the connection all the caches etc? Perhaps trying to allocate
shared memory?

JD

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