[pgpool-general: 9381] Re: WARNING: failed to lock semaphore

[Tatsuo Ishii]

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: http://www.sraoss.co.jp/index_en/
Japanese:http://www.sraoss.co.jp
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