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

davec(at)postgresintl(dot)com
www.postgresintl.com

On Thu, 28 Feb 2019 at 07:01, Švorc Martin <svorc(at)sefira(dot)cz> 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:* pgsql-jdbc-owner(at)postgresql(dot)org [mailto:
> pgsql-jdbc-owner(at)postgresql(dot)org] *On Behalf Of *Benoit Salotti
> *Sent:* Tuesday, June 28, 2016 11:41 AM
> *To:* pgsql-jdbc(at)postgresql(dot)org
> *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
>