[pgpool-general: 1935] Re: 40% performance loss when using pgpool with postgres foreign data wrapper
ishii at postgresql.org
Thu Jul 25 09:19:30 JST 2013
> On Tue, Jul 23, 2013 at 9:59 PM, Tatsuo Ishii <ishii at postgresql.org> wrote:
>>> On Tue, Jul 23, 2013 at 5:42 PM, Tatsuo Ishii <ishii at postgresql.org> wrote:
>>>> Not sure how is like your configuration. Did you actually test like this?
>>>> pgbench/psql -> CLUSTER_A -> PG_FDW -> pgpool_B -> CLUSTER_B
>>> Yes, that's the config that exhibited the 40% performance loss.
>> If you try this:
>> pgbench/psql -> pgpool_B -> CLUSTER_B
>> How is the performance?
> Perf is pretty good, nearly the same as:
> pgbench/psql -> CLUSTER_A
> Actual output:
> Scale option ignored, using pgbench_branches table count = 10000
> transaction type: TPC-B (sort of)
> scaling factor: 10000
> query mode: simple
> number of clients: 10
> number of threads: 10
> duration: 3600 s
> number of transactions actually processed: 7922742
> tps = 2200.752746 (including connections establishing)
> tps = 2200.760460 (excluding connections establishing)
> It seems conclusive that pgpool is somehow not handling the FDW stuff
> well. Can you try setting something similar up on your end, and see
> if you can reproduce the perf loss? It doesn't require any special
> data, just the normal default pgbench schema.
I'll give it a try when I have spare time. At this point my wild guess
is PG_FDW does not generate good enough query plan. Can you show
EXPLAIN VERBOSE result?
SRA OSS, Inc. Japan
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