Re: pgreplay log file replayer released

Dimitri Fontaine wrote:
> Greg Stark <gsstark(at)mit(dot)edu> writes:
>> Do you have a multi-threaded model that tracks which transactions each
>> query belonged to and runs them concurrently like they were in the
>> original setup? That's what I've been looking for.
>
> Tsung does that and has been doing it for… quite some time. It even
> comes with a recorder which is a PostgreSQL proxy: connect it to your
> server, connect your client to it, and let it record a session at a
> time.
>
> Then in the configuration you get to choose how many of each
> session you
> want to mix, etc.
>
> http://tsung.erlang-projects.org/

pgreplay is single-threaded, but uses asynchronous query processing,
so multiple connections can be handled simultaneously.

pgreplay will use as many connections as the original run did, and
query order and timing are retained.

This is the first time I hear of Tsung - it sounds like a good idea.

I guess it has some advantages over pgreplay; the biggest one that
I can see is that it will see things that are not logged, like
COPY data.

It seems that Tsung currently only supports "basic queries", but I
assume that this can be improved. One thing that Tsung, recording
queries as proxy, will never be able to handle are encrypted connections,
but I guess that's a minor problem.

On the usability side, Tsung will require that all clients are redirected
to the recording proxy, while pgreplay will only require that the logging
configuration settings on the server are changed. This can be an advantage
in large distributed production environments.

Yours,
Laurenz Albe