From: "Merlin Moncure" <mmoncure@xxxxxxxxx>
On Wed, May 9, 2012 at 8:06 AM, MauMau <maumau307@xxxxxxxxx> wrote:
Hello,
I've heard from some people that synchronous streaming replication has
severe performance impact on the primary. They said that the transaction
throughput of TPC-C like benchmark (perhaps DBT-2) decreased by 50%. I'm
sorry I haven't asked them about their testing environment, because they
just gave me their experience. They think that this result is much worse
than some commercial database.
I can't speak for other databases, but it's only natural to assume
that tps must drop. At minimum, you have to add the latency of
communication and remote sync operation to your transaction time. For
very short transactions this adds up to a lot of extra work relative
to the transaction itself.
Yes, I understand it is natural for the response time of each transaction to
double or more. But I think the throughput drop would be amortized among
multiple simultaneous transactions. So, 50% throughput decrease seems
unreasonable.
If this thinking is correct, and some could kindly share his/her past
performance evaluation results (ideally of DBT-2), I want to say to my
acquaintance "hey, community people experience better performance, so you
may need to review your configuration."
Regards
MauMau
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