On 07/24/2011 03:50 AM, Jeff Janes wrote:
On Mon, Jun 13, 2011 at 7:03 AM, Stefan Kaltenbrunner
ste...@kaltenbrunner.cc wrote:
On 06/13/2011 01:55 PM, Stefan Kaltenbrunner wrote:
[...]
all those tests are done with pgbench running on the same box - which
has a noticable impact on the
Jeff Janes jeff.ja...@gmail.com writes:
How was this profile generated? I get a similar profile using
--enable-profiling and gprof, but I find it not believable. The
complete absence of any calls to libpq is not credible. I don't know
about your profiler, but with gprof they should be
Stefan Kaltenbrunner ste...@kaltenbrunner.cc writes:
interesting - iirc we actually had some reports about current libpq
behaviour causing scaling issues on some OSes - see
http://archives.postgresql.org/pgsql-hackers/2009-06/msg00748.php and
some related threads. Iirc the final patch for that
On 07/24/2011 05:55 PM, Tom Lane wrote:
Stefan Kaltenbrunner ste...@kaltenbrunner.cc writes:
interesting - iirc we actually had some reports about current libpq
behaviour causing scaling issues on some OSes - see
http://archives.postgresql.org/pgsql-hackers/2009-06/msg00748.php and
some
On Mon, Jun 13, 2011 at 7:03 AM, Stefan Kaltenbrunner
ste...@kaltenbrunner.cc wrote:
On 06/13/2011 01:55 PM, Stefan Kaltenbrunner wrote:
[...]
all those tests are done with pgbench running on the same box - which
has a noticable impact on the results because pgbench is using ~1 core
per 8
On Mon, Jun 13, 2011 at 9:09 PM, Alvaro Herrera
alvhe...@commandprompt.com wrote:
I noticed that pgbench's doCustom (the function highest in the profile
posted) returns doing nothing if the connection is supposed to be
sleeping; seems an open door for busy waiting. I didn't check the
rest of
On 06/14/2011 02:27 AM, Jeff Janes wrote:
On Mon, Jun 13, 2011 at 7:03 AM, Stefan Kaltenbrunner
ste...@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
On 06/13/2011 01:55 PM, Stefan Kaltenbrunner wrote:
[...]
all those tests are done with pgbench running on the same box - which
has a noticable impact on the results because pgbench is using ~1 core
per 8 cores of the backend tested in cpu resoures - though I don't think
it causes any
On Mon, Jun 13, 2011 at 7:03 AM, Stefan Kaltenbrunner
ste...@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
On Tue, Jun 14, 2011 at 09:27, Jeff Janes jeff.ja...@gmail.com wrote:
pgbench sends each query (per connection) and waits for the reply
before sending another.
We can use -j option to run pgbench in multiple threads to avoid
request starvation. What setting did you use, Stefan?
for those
On 06/13/2011 08:27 PM, Jeff Janes wrote:
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?
Excerpts from Jeff Janes's message of lun jun 13 20:27:15 -0400 2011:
On Mon, Jun 13, 2011 at 7:03 AM, Stefan Kaltenbrunner
ste...@kaltenbrunner.cc wrote:
...
so it seems that sysbench is actually significantly less overhead than
pgbench and the lower throughput at the higher
On Tue, Jun 14, 2011 at 13:09, Alvaro Herrera
alvhe...@commandprompt.com wrote:
I noticed that pgbench's doCustom (the function highest in the profile
posted) returns doing nothing if the connection is supposed to be
sleeping; seems an open door for busy waiting.
pgbench uses select()
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