To: Greg Smith <greg@2ndquadrant.com>
cc: David Kerr <dmk@mr-paradox.net>, pgsql-performance@postgresql.org
Subject: Re: pgbench could not send data to client: Broken pipe 
In-reply-to: <4C87E3A6.8060800@2ndquadrant.com> 
References: <20100908174629.GD40339@mr-paradox.net>
	<8037.1283973026@sss.pgh.pa.us> <4C87E3A6.8060800@2ndquadrant.com>
Comments: In-reply-to Greg Smith <greg@2ndquadrant.com>
	message dated "Wed, 08 Sep 2010 15:27:34 -0400"
Date: Wed, 08 Sep 2010 15:44:36 -0400
Message-ID: <8754.1283975076@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>

Greg Smith <greg@2ndquadrant.com> writes:
> Tom Lane wrote:
>> So I think you could get above the FD_SETSIZE limit with a bit of
>> hacking if you were using 9.0's pgbench.  No chance with 8.3 though.

> I believe David can do this easily enough by compiling a 9.0 source code 
> tree with the "--disable-thread-safety" option.

It would take a bit more work than that, because the code still tries to
limit the client count based on FD_SETSIZE.  He'd need to hack it so
that in non-thread mode, the limit is FD_SETSIZE per subprocess.  I was
suggesting that an official patch to that effect would be a good thing.

> It's kind of futile to run pgbench simulating much more than a hundred 
> or two clients before 9.0 anyway.

Yeah ...

			regards, tom lane