postgres-xc-general Mailing List for Postgres-XC

You can try pgxc_pool_reload() and pgxc_pool_check() as found at
http://postgres-xc.sourceforge.net/docs/1_0_2/functions-admin.html

Another means is CLEAN CONNECTION statement,
http://postgres-xc.sourceforge.net/docs/1_0_2/sql-cleanconnection.html

Regards;
----------
Koichi Suzuki


2013/3/21 Chris Brown <cb...@in...>:
> Hi all,
>
> I have previously run successful tests with 2 datanodes and I'm trying to
> run the same test with 3 datanodes.  I am able to create/drop tables and
> insert/select rows from all 3 coordinators.  The test runs if I point it
> at a single coordinator (doesn't matter which one) and set the number of
> clients to 32.  Each datanode box is running
> datanode+coordinator(master)+gtm_proxy and gtm is running on a 4th box.
>
> I have upped max_pool_size on the coordinator and max_connections on the
> datanode to 400.  I haven't upped max_prepared_transactions however I
> don't think any of these single-row-and-table inserts will required a
> prepared transaction unless _all_ transactions use them (do they? And if
> they do, why does my 2-datanode test work?).
>
>
> Problem 1: If I use a single client, inserts seem to get stuck after about
> 12 (running a batch file with 6014 individual insert statements).  The
> process doing inserts (psql) just stops doing inserts and I don't see any
> output anywhere.
>
> Problem 2: If I use 64 clients connecting to all 3 coordinators (round
> robin so approx. 21 clients each) I get 'Failed to get pooled connection'
> errors.
>
> Problem 3: If I get 'Failed to get pooled connection' errors, the cluster
> is in a broken state from then on.  The only solution I've found is to
> dropdb then createdb which usually can't be accomplished without stopping
> the entire cluster and restarting it.
>
> What am I doing wrong?
>
> Chris...
>
>
> ------------------------------------------------------------------------------
> Everyone hates slow websites. So do we.
> Make your web apps faster with AppDynamics
> Download AppDynamics Lite for free today:
> http://p.sf.net/sfu/appdyn_d2d_mar
> _______________________________________________
> Postgres-xc-general mailing list
> Pos...@li...
> https://lists.sourceforge.net/lists/listinfo/postgres-xc-general

Hi Arni,
There are various scenarios under which we push join, it's difficult to
elaborate all of them. Between 1.0 and current head there have been a whole
bunch of changes in join push-down. You will find that in current head,
even the non-shippable joins are very fast, per my measurement and
Suzuki-san's measurement 100 times), owing to merge/hash join instead of
nested loop join. Which version are you trying out? Can you please try the
current head (for testing only, not production).

It will help you can specify your table structures, and queries.
On Thu, Mar 21, 2013 at 8:39 AM, Koichi Suzuki <koi...@gm...>wrote:

> Hi,
>
> XC pushes down join when join column of both table are distribution
> column if both tables are distributed by hash or modulo.   If one of
> the tables is replicated table or both tables are replicated table,
> join will be pushed down too.   We have much more variety of the
> statement context.   If you share your table structure (create table
> etc.), statement and its plan, it will be helpful if there's something
> wrong or if there's something helping.
>
> I hope Ashutosh will answer the question better.
>
> Regards;
> ----------
> Koichi Suzuki
>
>
> 2013/3/21 Arni Sumarlidason <Arn...@md...>:
> > What kind of logic does pgxc use to determine if a join can be can at
> the data node level vs the coordinator node level?
> >
> > My joins are occurring at the coordinator and the data is overwhelming
> the coordinator. I asked a similar question before, I thought this time I'd
> be more generic and focus on the core problem.
> >
> > Arni
> > Sent from my iPhone
> >
> ------------------------------------------------------------------------------
> > Everyone hates slow websites. So do we.
> > Make your web apps faster with AppDynamics
> > Download AppDynamics Lite for free today:
> > http://p.sf.net/sfu/appdyn_d2d_mar
> > _______________________________________________
> > Postgres-xc-general mailing list
> > Pos...@li...
> > https://lists.sourceforge.net/lists/listinfo/postgres-xc-general
>
>
> ------------------------------------------------------------------------------
> Everyone hates slow websites. So do we.
> Make your web apps faster with AppDynamics
> Download AppDynamics Lite for free today:
> http://p.sf.net/sfu/appdyn_d2d_mar
> _______________________________________________
> Postgres-xc-general mailing list
> Pos...@li...
> https://lists.sourceforge.net/lists/listinfo/postgres-xc-general
>



-- 
Best Wishes,
Ashutosh Bapat
EntepriseDB Corporation
The Enterprise Postgres Company

Hi,

XC pushes down join when join column of both table are distribution
column if both tables are distributed by hash or modulo.   If one of
the tables is replicated table or both tables are replicated table,
join will be pushed down too.   We have much more variety of the
statement context.   If you share your table structure (create table
etc.), statement and its plan, it will be helpful if there's something
wrong or if there's something helping.

I hope Ashutosh will answer the question better.

Regards;
----------
Koichi Suzuki


2013/3/21 Arni Sumarlidason <Arn...@md...>:
> What kind of logic does pgxc use to determine if a join can be can at the data node level vs the coordinator node level?
>
> My joins are occurring at the coordinator and the data is overwhelming the coordinator. I asked a similar question before, I thought this time I'd be more generic and focus on the core problem.
>
> Arni
> Sent from my iPhone
> ------------------------------------------------------------------------------
> Everyone hates slow websites. So do we.
> Make your web apps faster with AppDynamics
> Download AppDynamics Lite for free today:
> http://p.sf.net/sfu/appdyn_d2d_mar
> _______________________________________________
> Postgres-xc-general mailing list
> Pos...@li...
> https://lists.sourceforge.net/lists/listinfo/postgres-xc-general

What kind of logic does pgxc use to determine if a join can be can at the data node level vs the coordinator node level?

My joins are occurring at the coordinator and the data is overwhelming the coordinator. I asked a similar question before, I thought this time I'd be more generic and focus on the core problem.

Arni
Sent from my iPhone