Re: pg_ctl reload breaks our client

On Fri, Sep 16, 2005 at 02:16:29PM -0700, Marc Munro wrote:
> It is Postgres 7.3.6. The client is a multi-threaded C++ client. The
> breakage was that one group of connections simply stopped. Others
> contined without problem. It is not clear exactly what was going on.

How did the connections "stop"? Were the connections broken, causing
queries to fail? Or did queries block and never return? Or something
else? What was happening that shouldn't happen, or what wasn't
happening that should happen?

If the connections were still active but not returning, did you do
a process trace on the connection's postmaster or attach a debugger
to it to see what it was doing?

Could the timing of the problem have been coincidence? Have you
ever seen the problem without a reload? How often do you see the
problem after a reload? Do you know for certain that the application
was working immediately before the reload and not working immediately
after it?

What operating system are you using?

> Nothing in our application logs gives us any clue to this.

What about the postmaster logs?

> As for reproducibility, it has hapenned before in test environments when
> we have bounced the datanase. This is not too shocking as I would
> expect the client to notice this :-) It is a little more shocking when
> it's a reload. Or maybe I have simply misunderstood what reload does.

Can you reproduce the problem with a reload? A stop and start will
terminate client connections, but a reload shouldn't.

--
Michael Fuhr