Re: [BDR] Best practice to automatically abort a DDL operation when one node is down - Mailing list pgsql-general

From Sylvain MARECHAL
Subject Re: [BDR] Best practice to automatically abort a DDL operation when one node is down
Date
Msg-id 569CA2BE.9040406@gmail.com
Whole thread Raw
In response to Re: [BDR] Best practice to automatically abort a DDL operation when one node is down  (Craig Ringer <craig@2ndquadrant.com>)
List pgsql-general


 
What is the best practice to make sure the DDL operation will fail, possibly after a timeout, if one of the node is down?

statement_timeout

Ok. Thank-you for pointing this. I have just tried it, and this work great even for nodes that are not properly power off (plug removed).
 
I could check the state of the node before issuing the DDL operation, but this solution is far from being perfect as the node may fail right after this.

Correct, but it's still useful to do.

I'd check to see all nodes are connected in pg_stat_replication then I'd issue the DDL with a statement_timeout set.

Ok. For the first check, I was using bdr.bdr_test_remote_connectback(peer_dsn, local_dsn), getting the dsn from the bdr.bdr_nodes table; but using the pg_stat_replication table is problably quicker and simpler.

Thank-you again,

Sylvain

pgsql-general by date:

Previous
From: Craig Ringer
Date:
Subject: Re: BDR: cascading setup
Next
From: Devrim GÜNDÜZ
Date:
Subject: Re: [pgsql-pkg-yum] Missing RHEL rpm(pg_catcheck-95) in postgres 9.5 repo.