Re: Performance and Clustering

Jaime Rodriguez wrote:
> My customer requires that DBMS shall support 4000 simultaneous requests
> Also the system to be deploy maybe a cluster, with 12 microprocessors

In order to support 4000 true simultaneous requests, you'd need 4000
processor cores available.  What you probably mean here is that you
expect 4000 simultaneous database connections instead.  The number of
connections open and the number actually expected to be doing work at
any time are very different quantities, and that ratio is a critical
number you'll need to determine before you can estimate something here.

Generally a single PostgreSQL server can handle in the range of 100-1000
open connections at a time, depending on OS and hardware specs.  The
number of active queries running at any one time will be closer to the
number of cores in the server.

If most connections are read-only, there are a few ways to design a
cluster of systems to support the sort of design needed to scale up to
where you're aiming at.  Getting more than one node you can write to in
a cluster is much harder.

--
Greg Smith  2ndQuadrant US  Baltimore, MD
PostgreSQL Training, Services and Support
greg@2ndQuadrant.com   www.2ndQuadrant.us