Обсуждение: Number of Connections
Hello, I'm a bit new to postgres. Is there anyway to tell the current number of connections on a database or server? I'm having a connection closing problem and would like to debug it somehow. I know on Sybase you can check a sys table to determine this. Not familiar with how to do this on Postgres. Please advise and thank you.
> Hello,
>
> I'm a bit new to postgres. Is there anyway to tell the current number of
> connections on a database or server? I'm having a connection closing
> problem and would like to debug it somehow. I know on Sybase you can
check
> a sys table to determine this. Not familiar with how to do this on
> Postgres.
I use:
ps ax | grep postgres | wc -l
Note the value is often one to high because is picks up the grep process.
Use
ps ax | grep postgres
to look at the processes and see what IP are connected, what users, and what
the backend is doing (IDLE, SELECT, ..)
On Fri, Feb 16, 2001 at 02:09:42PM -0500, Bryan White wrote: > I use: > ps ax | grep postgres | wc -l > Note the value is often one to high because is picks up the grep process. Why not just remove 'grep' - i.e ps ax | grep postgres | grep -v grep | wc -l HTH, Neil -- Neil Conway <neilconway@home.com> Get my GnuPG key from: http://klamath.dyndns.org/mykey.asc Encrypted mail welcomed Four stages of acceptance: i) this is worthless nonsense; ii) this is an interesting, but perverse, point of view; iii) this is true, but quite unimportant; iv) I always said so. -- J. B. S. Haldane in Journal of Genetics 58:464 (1963).
Neil Conway <nconway@klamath.dyndns.org> writes:
> On Fri, Feb 16, 2001 at 02:09:42PM -0500, Bryan White wrote:
>> ps ax | grep postgres | wc -l
>> Note the value is often one to high because is picks up the grep process.
> Why not just remove 'grep' - i.e
> ps ax | grep postgres | grep -v grep | wc -l
Actually this is a standard problem with a standard solution: use a
not-so-literal grep pattern, eg
ps ax | grep '[p]ostgres' | wc -l
This pattern matches 'postgres' but not '[p]ostgres'. Problem solved.
regards, tom lane
What's the purpose of the "grep -v grep" ? Tim ----- Original Message ----- From: "Neil Conway" <nconway@klamath.dyndns.org> To: "pgsql-general" <pgsql-general@postgreSQL.org> Sent: Friday, February 16, 2001 12:05 PM Subject: Re: [GENERAL] Number of Connections > On Fri, Feb 16, 2001 at 02:09:42PM -0500, Bryan White wrote: > > I use: > > ps ax | grep postgres | wc -l > > Note the value is often one to high because is picks up the grep process. > > Why not just remove 'grep' - i.e > > ps ax | grep postgres | grep -v grep | wc -l > > HTH, > > Neil > > -- > Neil Conway <neilconway@home.com> > Get my GnuPG key from: http://klamath.dyndns.org/mykey.asc > Encrypted mail welcomed
The "-v" option tells grep to select everything EXCEPT the following term. Therefore, the "grep -v grep" section of the piped commands will delete the "extra" line (the one generated by the "grep postgres" command) that the ps command spits out prior to piping it into the "wc -l" command. Tim Barnard wrote: > What's the purpose of the "grep -v grep" ? > > Tim > > ----- Original Message ----- > From: "Neil Conway" <nconway@klamath.dyndns.org> > To: "pgsql-general" <pgsql-general@postgreSQL.org> > Sent: Friday, February 16, 2001 12:05 PM > Subject: Re: [GENERAL] Number of Connections > > > On Fri, Feb 16, 2001 at 02:09:42PM -0500, Bryan White wrote: > > > I use: > > > ps ax | grep postgres | wc -l > > > Note the value is often one to high because is picks up the grep > process. > > > > Why not just remove 'grep' - i.e > > > > ps ax | grep postgres | grep -v grep | wc -l > > > > HTH, > > > > Neil > > > > -- > > Neil Conway <neilconway@home.com> > > Get my GnuPG key from: http://klamath.dyndns.org/mykey.asc > > Encrypted mail welcomed -- John Burski Chief IT Cook and Bottlewasher 911 Emergency Products, St. Cloud, MN (320) 656 0076 www.911ep.com ++++++++++++++++++++++++++++++++++ + How's your cheese holding out? + ++++++++++++++++++++++++++++++++++
On Fri, 16 Feb 2001, Tim Barnard wrote:
> What's the purpose of the "grep -v grep" ?
It ignores listing of grep in the output stream.
-- Brett
http://www.chapelperilous.net/~bmccoy/
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Q: What do agnostic, insomniac dyslexics do at night?
A: Stay awake and wonder if there's a dog.
Thanks. Tim ----- Original Message ----- From: "John Burski" <John.Burski@911ep.com> To: "Tim Barnard" <tbarnard@povn.com> Cc: "pgsql-general" <pgsql-general@postgresql.org> Sent: Friday, February 16, 2001 2:47 PM Subject: Re: [GENERAL] Number of Connections > The "-v" option tells grep to select everything EXCEPT the following > term. Therefore, the "grep -v grep" section of the piped commands will > delete the "extra" line (the one generated by the "grep postgres" > command) that the ps command spits out prior to piping it into the "wc > -l" command. > > Tim Barnard wrote: > > > What's the purpose of the "grep -v grep" ? > > > > Tim > >