[pgpool-general: 9384] Re: WARNING: failed to lock semaphore

[Maria Nieva]

Dear Tatsuo,

Thank you for the patch.

I apologize for the inconvenience, but could you please provide guidance on
how to apply the patch to our Pgpool installation? As mentioned previously,
we installed Pgpool from source.

Thank you for your time and assistance.

Best Regards,
Maria



On Sat, Mar 1, 2025 at 6:12 AM Tatsuo Ishii <ishii at postgresql.org> wrote:

> Hi Maria,
>
> > Dear Tatsuo,
> >
> > Thank you for your response.
> >
> > I understand your point regarding the semaphore acquisition. However, I
> > would like to clarify that the semaphore error does not occur immediately
> > after startup. In our experience, the error manifests itself after weeks
> of
> > running Pgpool. This behavior has been observed in both our staging and
> > production environments.
> >
> > If the semaphore configuration is established during Pgpool startup, it
> > seems unusual that it would change weeks later. Could you please
> elaborate
> > on what might cause such a delayed configuration change?
>
> Ok, the semaphore is definitely created at the start up of pgpool. It
> should never been removed until pgpool shuts down. If it's removed,
> that must be a bug of pgpool. There's only 1 place where semaphore is
> removed (IpcSemaphoreKill). Can you apply attached patch to confirm
> the function is actually called? If you find semaphore is removed but
> IpcSemaphoreKill is not called, then the semaphore was removed by
> someone else.
>
> Best reagards,
> --
> Tatsuo Ishii
> SRA OSS K.K.
> English:
> https://protect2.fireeye.com/v1/url?k=31323334-501cfaeb-3131568e-454455535732-b2e8c335807c32bc&q=1&e=af34ac69-01a0-4305-af59-968a7ca1f337&u=http%3A%2F%2Fwww.sraoss.co.jp%2Findex_en%2F
> Japanese:http://www.sraoss.co.jp
>
>
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