Published on Tue, Jun 19, 2018
As you all know, EDB Failover Manager(EFM) provides the high availability insfrastructure for EDB Postgres clusters. Failover Manager monitors the members of a Postgres cluster, identifies and verifies database failures quickly and reliably, and if needed promotes a standby node to become the cluster master and issues alerts.
Every release of EFM has new features and functionalities and to take benefit of it you may need to upgrade your existing cluster to new version.
The Failover Manager 3.1 installer has an upgrade utility called “upgrade-conf” in “/usr/edb/efm-3.1/bin” directory, that locates the .properties & .nodes file of pre-existing EFM version 2.0,2.1 or 3.0 and creates a new copy of configuration files in /etc/edb/efm-3.1/ directory to be used by EFM 3.1 version.
Syntax:
/usr/edb/efm-3.1/bin/efm upgrade-conf <clustername>
Let’s see in play by upgrading the existing EFM cluster 3.0 to new EFM 3.1 version.
Check the existing EFM cluster status before proceeding to upgrade to EFM 3.1.
[root@witness efm]# /usr/edb/efm-3.0/bin/efm cluster-stauts efm
Cluster Status: efm
VIP:
Agent Type Address Agent DB Info
--------------------------------------------------------------
Master MASTER_IP UP UP
Standby STANDBY_IP UP UP
Witness WITNESS_IP UP N/A
Allowed node host list:
STANDBY_IP MASTER_IP WITNESS_IP
Membership coordinator: STANDBY_IP
Standby priority host list:
STANDBY_IP
Promote Status:
DB Type Address XLog Loc Info
--------------------------------------------------------------
Master MASTER_IP 0/160001A8
Standby STANDBY_IP 0/160001A8
Standby database(s) in sync with master. It is safe to promote.
You can understand with the output that I have Master,Standby and Witness nodes in my EFM cluster configuration.
Install latest version EFM 3.1 binaries on Master,Standby & Witness nodes. EFM binaries comes in rpms, to download you have to enable the EDB repository and follow the instructions mentioned here
yum install edb-efm31
After installing new EFM 3.1 binaries on all the 3 nodes, invoke “–help” to see the context of “upgrade-conf”.
# /usr/edb/efm-3.1/bin/efm --help
<trimmed other options>
upgrade-conf
Will create a 3.1 compatible .properties and .nodes file based on existing files.
Must be run with root privileges for default configuration.
Full command: efm upgrade-conf <cluster name>
To upgrade files from a non-sudo configuration, include the -source switch to
specify the path to the files. The new files will be written to the directory from
which the command is invoked, and will be owned by the user executing the command.
Full command: efm upgrade-conf <cluster name> -source <directory>
“upgrade-conf” utility should be executed on Master,Standby and Witness nodes. The utility will create a latest EFM 3.1 version configuration files(.properties & .nodes) from the pre-existing EFM 3.0 version. Below steps are executed on the Master Node, follow the same “upgrade-conf” steps on the Standby & Witness node.
EFM 3.0 configuration files
[root@master ]# ls -l /etc/edb/efm-3.0/
total 40
-rw-r--r--. 1 efm efm 180 Jun 18 19:00 efm.nodes
-rw-r--r--. 1 efm efm 16087 Jun 17 08:07 efm.properties
-rw-r--r--. 1 efm efm 139 Feb 22 02:20 efm.nodes.in
-rw-r--r--. 1 efm efm 15771 Feb 22 02:20 efm.properties.in
Run upgrade-conf command
[root@witness bin]# /usr/edb/efm-3.1/bin/efm upgrade-conf efm
Checking directory /etc/edb/efm-3.0
Processing efm.properties file
Removing log.dir value to use default.
The following properties were added in addition to those in previous installed version:
notification.level
stop.failed.master
stable.nodes.file
virtualIp.interface
virtualIp.single
lock.dir
Checking directory /etc/edb/efm-3.0
Processing efm.nodes file
Upgrade of files is finished. The owner and group for properties and nodes files have been set as 'efm'.
Check for the new configuration files in /etc/edb/efm-3.1
[root@master ]# ls -l /etc/edb/efm-3.1/
total 48
-rw-r--r--. 1 efm efm 179 Jun 18 19:16 efm.nodes
-rw-r--r--. 1 efm efm 17321 Jun 18 19:16 efm.properties
-rw-r--r--. 1 root root 139 May 17 23:55 efm.nodes.in
-rw-r--r--. 1 root root 17066 May 17 23:55 efm.properties.in
Note: During “upgrade-conf” step, old version EFM service should be running.
Now, stop the Old EFM service on all the nodes
systemctl stop efm-3.0.service
or
Use "stop-cluster" option to stop all EFM services
[root@master ]# /usr/edb/efm-3.0/bin/efm stop-cluster efm
Stop cluster command sent to 3 nodes.
Now start the EFM 3.1 service on all the nodes.
[root@master efm-3.1]# systemctl start efm-3.1.service
Note: If you are running EFM cluster with different cluster name then you need to edit/modify 3.1 version unit file with clustername and apply the unit file changes by running “systemctl daemon-reload”
Thats all, it took 5 steps to upgraded the existing EFM cluster to the new version EFM 3.1.