Re: Network write errors (was: Re: Feature freeze date for

Bruce Momjian <pgman@candle.pha.pa.us> writes:
> Andrew - Supernews wrote:
>> What's _not_ a good idea is ignoring the EPIPE error from write(), which
>> seems to currently be reported via ereport(COMMERROR) which doesn't try
>> and abort the query as far as I can tell.

> Where are you seeing this?  I looked from PostgresMain() to
> ReadCommand() to SocketBackend() to pq_getbyte() which returns EOF, and
> PostgresMain checks that and does a proc_exit(0).

It sounds like you were following the input-from-client logic.  Andrew
is complaining about the output-to-client side.

We deliberately don't abort on write-to-client failure.  There have
been periodic discussions about changing that, but I'm not convinced
that the advocates for a change have made a good case.  Right now,
it's predictable that the backend only fails due to loss of connection
when it waits for a new command.  The behavior would become much less
predictable if we allowed write failure to abort the query.  As an
example: whether an UPDATE command completes might depend on whether
any invoked triggers try to issue NOTICEs.
        regards, tom lane