Re: Backend dies for DBI

Bjorn Solberg <bjorn(at)geocities(dot)com> writes:
> The log file from postmaster simply says:

> --->
> StartTransactionCommand
> [...]
> ProcessQuery
> CommitTransactionCommand
> proc_exit(0)
> shmem_exit(0)
> exit(0)
> /usr/local/pgsql/bin/postmaster: reaping dead processes...
> /usr/local/pgsql/bin/postmaster: CleanupProc: pid 1297 exited with status 0
> proc_exit(0)
> shmem_exit(0)
> exit(0)
> /usr/local/pgsql/bin/postmaster: reaping dead processes...
> /usr/local/pgsql/bin/postmaster: CleanupProc: pid 1298 exited with status 0
> ---<

This looks absolutely normal --- there's no evidence here for anything
except normal backend exit. At least the backend thinks it's normal.
You should be looking for client or protocol-level problems.

> DBI (I think) sometimes output a message like "Backend message type 0x50
> arrived while idle". This can happen several times, and the crash does
> not occur directly following any of the messages.

This may indicate running out of memory for a query result on the client
side; libpq is not very graceful about dealing with that :-(. You
should check on the sizes of query results you are fetching and the
amount of memory available to your DBI applications. Fetching a few
rows at a time via a CURSOR is a good workaround if that seems to be
the problem.

regards, tom lane