Tutorial - Configuring a Simple Failover Manager Cluster¶
This tutorial describes quickly configuring a Failover Manager cluster in a test environment. Other sections in this guide provide key information that you should read and understand before configuring Failover Manager for a production deployment.
This tutorial assumes that:
A database server is running and streaming replication is set up between a master and one or two standby nodes.
You have installed Failover Manager on each node.
The example that follows creates a cluster named
You should start the configuration process on a master or standby node. Then, copy the configuration files to other nodes to save time.
Step 1: Create Working Configuration Files
Copy the provided sample files to create EFM configuration files, and correct the ownership:
cd /etc/edb/efm-3.6 cp efm.properties.in efm.properties cp efm.nodes.in efm.nodes chown efm:efm efm.properties chown efm:efm efm.nodes
Step 2: Create an Encrypted Password
Create the encrypted password (needed for the properties file):
/usr/edb/efm-3.6/bin/efm encrypt efm
Follow the onscreen instructions to produce the encrypted version of your database password.
Step 3: Update the efm.properties File
cluster_name.properties file contains parameters that
specify connection properties and behaviors for your Failover Manager
cluster. Modifications to property settings are applied when Failover
The following properties are the minimal properties required to configure a Failover Manager cluster. If you are configuring a production system, please see The Cluster Properties File for a complete list of properties.
Database connection properties (needed even on the witness so it can connect to other databases when needed):
db.user db.password.encrypted db.port db.database
Owner of the data directory (usually postgres or enterprisedb):
Only one of the following properties is needed. If you provide the service name, EFM will use a service command to control the database server when necessary; if you provide the location of the Postgres bin directory, EFM will use pg_ctl to control the database server.
The data directory in which EFM will find or create recovery.conf files:
Set to receive email notifications (the notification text is also included in the agent log):
This is the local address of the node and the port to use for EFM. Other nodes will use this address to reach the agent, and the agent will also use this address for connecting to the local database (as opposed to connecting to localhost). An example of the format is included below:
Set this property to
true on a witness node and
false if it is a master
If you are running on a network without access to the Internet, change this to an address that is available on your network:
When configuring a production cluster, the following properties can be either true or false depending on your system configuration and usage. Set them both to true to simplify startup if you’re configuring an EFM test cluster.
Step 4: Update the efm.nodes File
cluster_name.nodes file is read at startup to tell an agent
how to find the rest of the cluster or, in the case of the first node
started, can be used to simplify authorization of subsequent nodes.
Add the addresses and ports of each node in the cluster to this file. One node will act as the membership coordinator; the list should include at least the membership coordinator’s address; for example:
Please note that the Failover Manager agent will not verify the content
efm.nodes file; the agent expects that some of the addresses in
the file cannot be reached (e.g. that another agent hasn’t been started
yet). For more information about the
see The Cluster Members File
Step 5: Configure the Other Nodes
efm.nodes files to the
directory on the other nodes in your sample cluster. After copying the
files, change the file ownership so the files are owned by
efm.properties file can be the same on every node, except for the
bind.addressproperty to use the node’s local address.
trueif the node is a witness node. If the node is a witness node, the properties relating to a local database installation will be ignored.
Step 6: Start the EFM Cluster
On any node, start the Failover Manager agent. The agent is named
efm-3.6; you can use your platform-specific service command to control
the service. For example, on a CentOS or RHEL 7.x host use the command:
systemctl start efm-3.6
On a a CentOS or RHEL 6.x host use the command:
service efm-3.6 start
After the agent starts, run the following command to see the status of the single-node cluster. You should see the addresses of the other nodes in the Allowed node host list.
/usr/edb/efm-3.6/bin/efm cluster-status efm
Start the agent on the other nodes. Run the
efm cluster-status efm
command on any node to see the cluster status.
If any agent fails to start, see the startup log for information about what went wrong:
Performing a Switchover
If the cluster status output shows that the master and standby(s) are in sync, you can perform a switchover with the following command:
/usr/edb/efm-3.6/bin/efm promote efm -switchover
The command will promote a standby and reconfigure the master database as a new standby in the cluster. To switch back, run the command again.
For quick access to online help, you can invoke the following command:
/usr/edb/efm-3.6/bin/efm promote efm --help
For detailed information about using the efm command line tool, see Using the EFM Utility.