[added performance list back]
On 12/06/2012 10:04 AM, John Lister wrote:
Thanks for the info, I'll have a play and see what values I get with similar settings, etc
you're welcome
Still think something is wrong with my config, but we'll see.
which kind of ssd disks do you have ?
maybe they are of the same typeShaun Thomas is having problem with here:
http://archives.postgresql.org/pgsql-performance/2012-12/msg00030.php
Andrea
john
On 06/12/2012 08:44, Andrea Suisani wrote:
Hi John,
On 12/06/2012 09:29 AM, John Lister wrote:
on this box:
in a brief: the box is dell a PowerEdge r720 with 16GB of RAM,
the cpu is a Xeon 5620 with 6 core, the OS is installed on a raid
(sata disk 7.2k rpm) and the PGDATA is on separate RAID 1 array
(sas 15K rpm) and the controller is a PERC H710 (bbwc with a cache
of 512 MB). (ubuntu 12.04)
on the same machine with the same configuration,
having PGDATA on a xfs formatted partition gives me
a much better TPS.
e.g. pgbench -c 20 -t 5000 gives me 6305 TPS
(3 runs with "echo 3 > /proc/sys/vm/drop_caches && /etc/init.d/postgresql-9.2 restart"
in between).
Hi, I found this interesting as I'm trying to do some benchmarks on my box which is
> very similar to the above but I don't believe the tps is any where near what it should be.
> Is the 6305 figure from xfs?
yes, it is.
I'm assuming that your main data array is just 2 15k sas drives,
correct
are you putting the WAL on the data array or is that stored somewhere else?
pg_xlog is placed in the data array.
Can I ask what scaling params,
sure, I've initialized pgbench db issuing:
pgbench -i -s 10 pgbench
etc you used to build the pgbench tables and look at your postgresql.conf file to see if I missed something (offline if you wish)
those are non default values in postgresql.conf
listen_addresses = '*'
max_connections = 100
shared_buffers = 3200MB
work_mem = 30MB
maintenance_work_mem = 800MB
synchronous_commit = off
full_page_writes = off
checkpoint_segments = 40
checkpoint_completion_target = 0.9
random_page_cost = 3.5
effective_cache_size = 10GB
log_timezone = 'localtime'
stats_temp_directory = 'pg_stat_tmp_ram'
autovacuum_naptime = 5min
and then OS tweaks:
HT bios disabled
/sbin/blockdev --setra 8192 /dev/sdb
echo deadline > /sys/block/sdb/queue/scheduler
vm.swappiness=0
vm.overcommit_memory=2
vm.dirty_ratio=2
vm.dirty_background_ratio=1
kernel.shmmax=3454820352
kernel.shmall=2048341
$PGDATA is on xfs (rw,noatime)
tmpfs on /db/9.2/pg_stat_tmp_ram type tmpfs (rw,size=50M,uid=1001,gid=1001)
kernel 3.2.0-32-generic
Andrea
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