[Postgres-xc-general] Postgres-XC Performance

[Aurelienne A. S. J. <aur...@gm...>]

Hello!

I'm a post-graduation student and my conclusion work is about Postgres-XC.
I've read a lot about the project and I really think this is a powerful
tool. Unfortunately, I couldn't achieve the performance I had expected.

I've configured a cluster with 4 virtualized servers (all of them on the
same hardware using Virtual Box):
Server 1: gtm
Server 2: 1 gtm_proxy + 1 datanode + 1 coordinator
Server 3: 1 gtm_proxy + 1 datanode + 1 coordinator
Server 4: 1 gtm_proxy + 1 datanode + 1 coordinator

The version of Postgres-XC I'm using is 1.0.3, and the OS in all servers is
Debian 7.

I used pgbench to compare the number of transactions per second in
Postgres-XC and in a standalone PostgreSQL server. Postgres-XC achieved
only half TPS compared to PostgreSQL. The test was basically consisted of
inserts into distributed tables (I used a custom script in pgbench) simulating
many clients simultaneously.

I would like to know what configuration would be enough to have a better
performance than PostgreSQL.

- How many servers would be enough to have a write/read scalability
compared to a single PostgreSQL?

- Would it be a problem to have all servers on the same hardware?

- Should I distribute the workload among all coordinators? I'm basically
using one coordinator, once I couldn't find a way to use all of them
simultaneously
with pgbench.

I would be very thankful if you could help me.


Regards,

Aurelienne Jorge.