Horton

Re: pgbench cpu overhead (was Re: lazy vxid locks, v1)

Stefan Kaltenbrunner <stefan@kaltenbrunner.cc>

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From: Stefan Kaltenbrunner <stefan@kaltenbrunner.cc>
To: Jeff Janes <jeff.janes@gmail.com>
Cc: pgsql-hackers@postgresql.org, Robert Haas <robertmhaas@gmail.com>
Date: 2011-06-14T20:05:58Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Avoid extra system calls to block SIGPIPE if the platform provides either

On 06/14/2011 02:27 AM, Jeff Janes wrote:
> On Mon, Jun 13, 2011 at 7:03 AM, Stefan Kaltenbrunner
> <stefan@kaltenbrunner.cc> wrote:
> ...
>>
>>
>> so it seems that sysbench is actually significantly less overhead than
>> pgbench and the lower throughput at the higher conncurency seems to be
>> cause by sysbench being able to stress the backend even more than
>> pgbench can.
> 
> Hi Stefan,
> 
> pgbench sends each query (per connection) and waits for the reply
> before sending another.
> 
> Do we know whether sysbench does that, or if it just stuffs the
> kernel's IPC buffer full of queries without synchronously waiting for
> individual replies?
> 
> I can't get sysbench to "make" for me, or I'd strace in single client
> mode and see what kind of messages are going back and forth.

yeah sysbench compiled from a release tarball needs some
autoconf/makefile hackery to get running on a modern system - but I can
provide you with the data you are interested in if you tell me exactly
what you are looking for...


Stefan