[Postgres-xc-general] Postgres-xc High Availability/Failover concerns

[Phil S. <phi...@ne...>]

Hi all ...

After running some some preliminary testing on our postgres-xc dev 
sandbox, I've come across some major concerns with High Availability and 
Failover.  I am hoping someone will be able to provide some insight on 
how to set up seamless high-available failover in a postgres-xc environment.


Here are the details:
--------------------

In the postgres-xc dev sandbox, a test table with the default 
round-robin distribution was created to test simultaneous DML SQL 
running on both db VMs.

With the DML SQL running, the coordinator and datanode on one of the db 
VMs was brought down (NB the host was not shut down, just the 
postgres-xc processes on the VM).  After a very short time (lets say max 
of 2 minutes), the DML SQL script running on the current active db VM 
started failing with the following error :
         ERROR:  Failed to get pooled connections

Our application requires 0 single points of failure.  If one of the db 
VMs goes down, the application needs the ability to automatically detect 
this outage and use the remaining active db VMs in the postgres-xc cluster.

Basically, I need to know how to set up the postgres-xc cluster to 
enable the applications to continue to run DML SQL when one of the db 
VMs goes down.  If this is not supported, then what would need to be put 
in place to allow for seamless high-available failover for a postgres-xc 
cluster.

Thanks in advance,
Phil.