Обсуждение: Promoting 1 of 2 slaves
Hello,
I am getting ready to take my master server out of service today and promote the slave to take it's place. In my current setup I have one master server which ships WAL files to two separate slave servers.
My plan is to promote one of those slaves. How do I get the slave that I promoted to start replicating to the other slave the moment I trigger it's promotion?
Thanks,
-Joseph Kregloh
As I am aware, you would have two options depending on your configuration:
- Change the primary_conninfo value on the second standby's recovery.conf to point to the standby that has been promoted to master. However, I think this would require that instance to be rebooted for the configuration changes to take effect
- Modify the DNS entries so that the host value in primary_conninfo points to the new master rather than the old master
Does anyone know of another way?
Will J. Dunn
On Fri, Jul 17, 2015 at 9:43 AM, Joseph Kregloh <jkregloh@sproutloud.com> wrote:
Hello,I am getting ready to take my master server out of service today and promote the slave to take it's place. In my current setup I have one master server which ships WAL files to two separate slave servers.My plan is to promote one of those slaves. How do I get the slave that I promoted to start replicating to the other slave the moment I trigger it's promotion?Thanks,-Joseph Kregloh
What I ended up doing was:
1. Stopping the master.
2. Triggering the promotion of slave A.
3. After slave A was promoted I turned it off and modified the postgresql.conf file to make it a permanent master and setup WAL shipping to slave B.
4. Rsync the pg_xlog directory from slave A to slave B and set recovery_target_timeline to latest
5. Start slave B, then start slave A now master.
So far everything seems to work.
-Joseph Kregloh
On Tue, Jul 21, 2015 at 2:37 PM, William Dunn <dunnwjr@gmail.com> wrote:
As I am aware, you would have two options depending on your configuration:
- Change the primary_conninfo value on the second standby's recovery.conf to point to the standby that has been promoted to master. However, I think this would require that instance to be rebooted for the configuration changes to take effect
- Modify the DNS entries so that the host value in primary_conninfo points to the new master rather than the old master
Does anyone know of another way?Will J. DunnOn Fri, Jul 17, 2015 at 9:43 AM, Joseph Kregloh <jkregloh@sproutloud.com> wrote:Hello,I am getting ready to take my master server out of service today and promote the slave to take it's place. In my current setup I have one master server which ships WAL files to two separate slave servers.My plan is to promote one of those slaves. How do I get the slave that I promoted to start replicating to the other slave the moment I trigger it's promotion?Thanks,-Joseph Kregloh