Re: [Postgres-xc-general] ERROR: Failed to get pooled connections

[Michael P. <mic...@gm...>]

On Wed, Oct 24, 2012 at 5:38 PM, Vladimir Stavrinov <vst...@gm...>wrote:

> On Wed, Aug 01, 2012 at 06:22:27PM +0900, Michael Paquier wrote:
>
> >>      I thought HA & LB is main feature of any cluster.
> >
> >    Transparency and scalability are even more important.
>
> Really? If You should rewrite every "CREATE TABLE" statement, when You
> need write scalability, is it "Transparency"? And if You should recreate
> entire cluster from scratch, when You need to add a node, is it
> "scalability"?
>
> It is hard to imagine who will use in production environment such
> cluster without HA, LB, transparency and scalability. I don't want to
> compare Your creature with mysql cluster at least because it is in
> memory database, but it has all of those features, absolutely
> necessary for any cluster.
>
Sure, XC provides thanks to its architecture naturally transparency and
scalability.
Load balancing can be provided between Coordinator and Datanodes depending
on applications, or at Coordinator level using an extra layer providing
this functionality.
For HA, Koichi is currently working on some tools to provide that, tools
you can find here:
https://github.com/koichi-szk/PGXC-Tools

Like Postgres, you need an external application to provide it.

I am not sure you can that easily compare XC and mysql cluster, both share
the same architectures, but once of the main differences coming to my mind
is that XC is far more flexible in terms of license (BSD and not GPL), and
like PostgreSQL, no company has the control of its code like mysql products
which Oracle relies on.
-- 
Michael Paquier
http://michael.otacoo.com