Re: How to achieve sustained disk performance of 1.25 GB write for 5 mins

On Wed, Nov 17, 2010 at 9:26 AM, Eric Comeau <ecomeau(at)signiant(dot)com> wrote:
> This is not directly a PostgreSQL performance question but I'm hoping some
> of the chaps that build high IO PostgreSQL servers on here can help.
>
> We build file transfer acceleration s/w (and use PostgreSQL as our database)
> but we need to build a test server that can handle a sustained write
> throughput of 1,25 GB for 5 mins.
>
> Why this number, because we want to push a 10 Gbps network link for 5-8
> mins, 10Gbps = 1.25 GB write, and would like to drive it for 5-8 mins which
> would be 400-500 GB.
>
> Note this is just a "test" server therefore it does not need fault
> tolerance.

I really doubt you will see 1.25gb/sec over 10gige link. Even if you
do though, you will hit a number of bottlenecks if you want to see
anything close to those numbers. Even with really fast storage you
will probably become cpu bound, or bottlenecked in the WAL, or some
other place.

*) what kind of data do you expect to be writing out at this speed?
*) how many transactions per second will you expect to have?
*) what is the architecture of the client? how many connections will
be open to postgres writing?
*) how many cores are in this box? what kind?

merlin