Re: pgbench results on a new server

On 6/25/10 12:03 PM, Greg Smith wrote:
> Craig James wrote:
>> I've got a new server and want to make sure it's running well.
>
> Any changes to the postgresql.conf file? Generally you need at least a
> moderate shared_buffers (1GB or so at a minimum) and checkpoint_segments
> (32 or higher) in order for the standard pgbench test to give good results.

max_connections = 500
shared_buffers = 1000MB
work_mem = 128MB
synchronous_commit = off
full_page_writes = off
wal_buffers = 256kB
checkpoint_segments = 30
effective_cache_size = 4GB

For fun I ran it with the installation defaults, and it never got above 1475 TPS.

>> pgbench -c20 -t 5000 -U test
>> tps = 5789
>> pgbench -c30 -t 3333 -U test
>> tps = 6961
>> pgbench -c40 -t 2500 -U test
>> tps = 2945
>
> General numbers are OK, the major drop going from 30 to 40 clients is
> larger than it should be. I'd suggest running the 40 client count one
> again to see if that's consistent.

It is consistent.  When I run pgbench from a different server, I get this:

    pgbench -c40 -t 2500 -U test
    tps = 7999

    pgbench -c100 -t 1000 -U test
    tps = 6693

Craig