RE: How to send queries to master and failover to slave ?

Švorc Martin <[email protected]> Fri, 1 Mar 2019 10:16:39 +0000
Newsgroups gmane.comp.db.postgresql.jdbc
Message-ID <VI1PR05MB5295BA974B84191217A6A613BC760@VI1PR05MB5295.eurprd05.prod.outlook.com>
Okay thanks, I have opened a pull request for the feature: #1430

Martin

From: Dave Cramer [mailto:[email protected]]
Sent: Thursday, February 28, 2019 1:24 PM
To: Švorc Martin
Cc: [email protected]
Subject: Re: How to send queries to master and failover to slave ?

If you have a use case for it then I think it's a good idea

Dave Cramer

[email protected]<mailto:[email protected]>
www.postgresintl.com<http://www.postgresintl.com>


On Thu, 28 Feb 2019 at 07:01, Švorc Martin <[email protected]<mailto:[email protected]>> wrote:
Hello,

We have the very same scenario as Benoit describes – if the master instance fails, we would like the driver to communicate with the secondary instance for read-only operations before the failover process is commenced. The second use-case is when the master instance is deliberately shut down for maintenance reasons  and we do not want to fail over to the secondary instance, but instead allow it to process user queries throughout the maintenance.

For this, we intend to implement "preferMaster" targetServerType in the JDBC driver paramater. Would you consider it a good idea to integrate this feature into the official JDBC driver?

Cheers

Martin

From: [email protected]<mailto:[email protected]> [mailto:[email protected]<mailto:[email protected]>] On Behalf Of Benoit Salotti
Sent: Tuesday, June 28, 2016 11:41 AM
To: [email protected]<mailto:[email protected]>
Subject: How to send queries to master and failover to slave ?

Hi all,

I have a setup with 1 master and 1 slave (hot standy to serve read queries if necessary).
I would like the JDBC driver to talk preferrably to the master (to be sure to get the freshest data). If the master is not available I would like to send the queries to the slave.

The documentation mentions the following values for the parameter targetServerType: any, master, slave, preferSlave.
I'm surprised there is no preferMaster option which would allow me to implement easily my requirement.

Anyone already encountered the same need ?

Regards,

Benoit