[Pgpool-general] slow pgpool-II-3.1

[Guillaume Lelarge]

On Thu, 2011-10-06 at 18:44 +0200, Olivier NOEL wrote:
> 2011/10/6 Guillaume Lelarge <guillaume at lelarge.info>:
> > On Thu, 2011-10-06 at 17:27 +0200, Olivier NOEL wrote:
> >> 2011/10/6 Guillaume Lelarge <guillaume at lelarge.info>:
> >>
> >> [...]
> >>
> >> >> And it's not. Ok, there is some overhead, but it's veeery slow.
> >> >>
> >> >
> >> > How did you check that?
> >> >
> >> > You may be right in a specific setting, but I have no issues getting
> >> > better performance with pgpool.
> >>
> >> We tested our java webapp with pgpool and without pgpool, same
> >> servers, we only change the target IP in the JDBC config file in
> >> Tomcat.
> >>
> >
> > I suppose you don't use a pooling mode in your java app? because they
> > may interfere.
> 
> No pooling, just the basic configuration of JDBC.
> 

Is JDBC autocommit on?

> >> We have a small XML processing servlet with informations to insert in
> >> the databases (streaming replication). We verified that all requests a
> >> balanced.
> >>
> >> XML sizes varies from 300KB to 3MB.
> >>
> >
> > Not sure what you mean with this. Are your queries this size? What do
> > you do with the XML? what kind of queries (SELECT, INSERT)?
> 
> My XML contains the data I have to insert in my database (list,
> informations about customers, etc.), data is prepared and inserted.
> All kind of queries DDL/DML/SELECT, etc.

> >> Time to process the file completely for a fully functional database :
> >>
> >> - with pgpool : 20-45min (20min for the smaller ones to 45min for the big one)
> >> - without pgpool : 4-15min
> >>
> >
> > How many users? same PostgreSQL database, and same PostgreSQL user?
> 
> 120 simultaneous users (webapp, max JDBC connections 25 per user),
> same database and user, but we have the same problem with every
> database.
> 
> >> Then we tested browsing in our webapp :
> >>
> >> - with pgpool : 30-45s to display a list of full customers
> >> informations (depending on the numbers of customers, 2400 to 12000
> >> customers on the same page)
> >> - without pgpool : 5-10s
> >>
> >
> > Same questions. How many users try to connect to pgpool? how long last
> > their sessions? what kind of queries?
> 
> We have 120 simultaneous users with a maximum of 25 connections per
> user (1000 connections per server, 3000 connections in pgpool)
> 
> Sessions? in JDBC? in webapp? in pgpool?

Sessions in PostgreSQL.

> All kind of queries DML/DDL/SELECT, etc.
> 

The numbers you provided show your app to be a lot slower with pgpool
than without. I fail to see why. In my experience, it usually is much
faster.


-- 
Guillaume
  http://blog.guillaume.lelarge.info
  http://www.dalibo.com