How to connect to PostgreSQL cluster?

[youngerong]

Deploy two PostgreSQL in two machine for high available, how to make Parse connect to the cluster? For example, 'mongodb://' + "10.43.159.58:9927,10.43.159.58:9928" + '/test?replicaSet=volunteer_test&readPreference=primaryPreferred, but PostgreSQL support this style?

[flovilmart]

You should have a look at the cluster documentations:

https://www.postgresql.org/docs/8.3/static/creating-cluster.html
https://wiki.postgresql.org/wiki/Replication,_Clustering,_and_Connection_Pooling

and probably pg-promise that we use under the hood, we pass the URL with a parser so it can be used to connect through the pg-promise library, @vitaly-t any idea?

[vitaly-t]

It doesn't exist in the driver, see brianc/node-postgres#932

From the pg-promise point of view, one would be creating 2 separate Database objects, with connection details for each cluster.

[flovilmart]

Thanks @vitaly-t !

[shreeramk]

@vitaly-t does pg-promise supports multiple host connection since for replica, it would be required or is there any other alternative ?

[vitaly-t]

@shreeramk pg-promise is neutral to this, it is the driver underneath that's expected to support it, as per this issue. They claim that the Native Binding supports it, but I never saw it working, so cannot say.

[shreeramk]

@vitaly-t okay. Is there any other way? Like writing a wrapper?

Consider if a wrapper is written on top of node-postgres, to handle separate connections to primary and multiple secondary's. Then, if I have total 5 nodes(1 - primary, 4 - secondary) that means using node-postgres i hv to create 5 separate connections. Would you recommend that?

Also, if any automatic failover libraries are used at postgres level, then obviously there are chances that if primary goes down then one of the secondary will promoted to primary so how do we handle that scenario in nodejs code.

[vitaly-t]

@shreeramk There is little I can suggest about it presently. And in any case, you will do better asking about it in that issue, and not here.