[Pgcluster-general] slow data-read performances

[Filip Rembiałkowski]

2008/8/18 Julien Garet <Julien.Garet at inria.fr>:
> Hi,
>
>   I've just setup a testing cluster of postgresql with pglcuster and there
> is something and do understand with the perfs. My setup is quite simple, I
> have two identical boxes with database and replicator under centos 5, it
> works well. I have done some testing  with pgbench and a third identical box
> running postgres 8.3 without postgres as reference.
>    The number of tps is about 5 times less in the cluster compared to the
> reference box, using all kind of queries of pgbench (1 select, 1 insert et 3
> update), which is quite normal, due to the overhead of the cluster in
> writing data. But when I use pgbench, only using select queries, the nodes
> of the cluster are still 5 times slower than the reference postgresql
> server. And I don't understand that as pgcluster isn't supposed to replicate
> data-read queries between nodes, the data-read performances should be the
> same as the reference. Are there any clues to this mysterious thing ?
>

Hello

How many client connections are you using?

Are you connecting to pglb? If you connect to one of cluster dbs there
will be no load balancing.

Can you email pgbench commandline and results here?


regards



-- 
Filip Rembiałkowski