[Pgpool-general] Duration of commit on more than one backend configuration

[Tatsuo Ishii]

> On 06/21/2010 10:16 PM, Tatsuo Ishii wrote:
> >> On 06/21/2010 08:31 PM, Tatsuo Ishii wrote:
> >>>> As far as I know, pgpool-II waits for [all] backends to commit the SQL
> >>>> statements (under replication mode) before returning to the client,
> >>>> right? This means that if, for example, one of the backends is very busy
> >>>> (100% CPU, etc.), pgpool will experience a delay and so will the
> >>>> application. Is this correct?
> >>>
> >>> Correct. This is a known behavior of all synchronous replication
> >>> systems. This ensures that committed data (from client's point of
> >>> view) is actually committed to all backends.
> >>
> >> Is there a way to set a timeout for this? It would be interesting the
> >> possibility of setting a timeout, and if it expires, the possibility of
> >> automatically degenerate the backend.
> > 
> > I think you could use PostgreSQL's statement_timeout for this purpose.
> 
> This will automatically degenerate the backend and restore normal
> services?

No.

> If a backend has problems, it is interesting that pgpool-II be
> able to degenerate it and restore normal services by using the other
> available backends.

I'm not sure just taking long time to execute a query is the trigger
of degeneration.
--
Tatsuo Ishii
SRA OSS, Inc. Japan
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