Using the efm utility v5

Failover Manager provides the efm utility to assist with cluster management. The RPM installer adds the utility to the /usr/edb/efm-5.<x>/bin directory when you install Failover Manager.

efm allow-node

efm allow-node <cluster_name> <address>

Invoke the efm allow-node command to allow the specified node to join the cluster. When invoking the command, provide the name of the cluster and the IP address of the joining node.

This command must be invoked by efm, a member of the efm group, or root.

efm disallow-node

efm disallow-node <cluster_name> <address>

Invoke the efm disallow-node command to remove the specified node from the allowed hosts list and prevent the node from joining a cluster. Provide the name of the cluster and the address of the node when calling the efm disallow-node command. This command must be invoked by efm, a member of the efm group, or root.

efm cluster-status

efm cluster-status <cluster_name>

Invoke the efm cluster-status command to display the status of a Failover Manager cluster. For more information about the status report, see Monitoring a Failover Manager cluster.

efm cluster-status-json

efm cluster-status-json <cluster_name>

Invoke the efm cluster-status-json command to display the status of a Failover Manager cluster in JSON format. While the format of the displayed information is different from the display generated by the efm cluster-status command, the information source is the same.

The following example is generated by querying the status of a healthy cluster with three nodes:

{
    "nodes": {
        "172.16.144.176": {
            "type": "Witness",
            "db": "N\/A",
            "vip": "",
            "vip_active": false
        },
        "172.16.144.177": {
            "type": "Primary",
            "db": "UP",
            "vip": "",
            "vip_active  :   false"
            "lsnReceive :   0/14001478"
            "lsn    :   0/14001478"
            "lsnInfo    :"
        },
        "172.16.144.180": {
            "type": "Standby",
            "db": "UP",
            "vip": "",
            "vip_active  :   false"
            "lsnReceive :   0/14001478"
            "lsn    :   0/14001478"
            "lsnInfo    :"
        }
    },
    "allowednodes": [
        "172.16.144.177",
        "172.16.144.160",
        "172.16.144.180",
        "172.16.144.176"
    ],
    "membershipcoordinator": "172.16.144.177",
    "failoverpriority": [
        "172.16.144.180"
    ],
    "minimumstandbys": 0,
    "missingnodes": [],
    "messages": []
}

efm create-standby

efm create-standby <cluster_name> [-prompt] [-slot <slot_name>]

Invoke the efm create-standby command to create a new standby database on this node. The local agent must be running and there must be a primary agent in the cluster. The command process will:

• Connect to local agent to find the current primary database
• Stop the local database and have the local agent become idle (if needed)
• If a slot parameter was specified, contact the primary database to drop a slot with that name if it exists and use create a new slot with this name for the standby to use
• Remove the local data directory
• Run pg_basebackup to create the standby database
• Start the standby database and resume monitoring

If the -prompt option is specified, the command will output the steps it will take, including the generated pg_basebackup command, before proceeding. The following agent properties are used:

• db.service.owner specifies the user running the pg_basebackup command
• sudo.user.command specifies how the command is run as the above user
• db.bin specifies the location of pg_basebackup
• db.data.dir specifies the target directory
• db.port specifies the port used to access the primary database
• application.name specifies the application_name to use (if set)

This command must be invoked with superuser privileges in order to perform database and Failover Manager operations.

The following example shows the command output when both the -prompt and -slot options are specified:

# /usr/edb/efm-5.0/bin/efm create-standby efm -slot s2 -prompt
Found primary 172.17.0.2 from cluster status.
Verify primary address 172.17.0.2 does not match this agent's bind address '172.17.0.3' or external address ''.
Will signal local agent to run database stop command and become idle if not already.
Will connect to primary on 172.17.0.2 to drop slot s2 if it exists.
Will remove the /opt/postgres/data directory and run the following command:
sudo -u postgres /usr/pgsql-17/bin/pg_basebackup -R -D /opt/postgres/data -X stream -S s2 -C -d "host=172.17.0.2 port=5432 application_name=bnode2"

Do you want to continue? [y/N]:y
Signalling local agent to stop db and become idle if needed.
Replication slot s2 does not exist on primary 172.17.0.2.
Running sudo -u postgres rm -rf /opt/postgres/data
Running sudo -u postgres /usr/pgsql-17/bin/pg_basebackup -R -D /opt/postgres/data -X stream -S s2 -C -d "host=172.17.0.2 port=5432 application_name=bnode2"
Starting database.
Waiting briefly for database to finish startup.
Attempting to resume local efm agent monitoring.
Resume command successful on local agent.

efm encrypt

efm encrypt <cluster_name> [--from-env]

Invoke the efm encrypt command to encrypt the database password before including the password in the cluster properties file. Include the --from-env option to instruct Failover Manager to use the value specified in the EFMPASS environment variable and execute without user input. For more information, see Encrypting your database password.

efm promote

efm promote cluster_name [-switchover [-sourcenode <address>][-quiet][-noscripts]

The efm promote command instructs Failover Manager to perform a manual failover of standby to primary.

Attempt a manual promotion only during a maintenance window for your database cluster and if the status command reports that all standbys in the cluster are up to date with the primary.

Include the –switchover clause to promote a standby node and reconfigure a primary node as a standby node. Include the -sourcenode keyword, and specify a node address to indicate the node whose recovery settings to copy to the old primary node, which makes it a standby. Include the -quiet keyword to suppress notifications during the switchover process. Include the -noscripts keyword to instruct Failover Manager not to invoke fencing or post-promotion scripts.

This command must be invoked by efm, a member of the efm group, or root.

efm reset-members

efm reset-members <cluster_name>

Invoke the efm reset-members command to remove cached node addresses from a Failover Manager cluster. Run this command after a node is permanently removed from the cluster to prevent the cluster from trying to connect to the removed node's address. This will also remove DOWN nodes after they have failed or have been disconnected from this cluster.

Running this command does the following on each node in the cluster:

1. Resets the addresses in the .nodes file to the current cluster members. This occurs even if the stable.nodes.file property is set to true.

2. Updates the Allowed Node host list to include only the current members.

3. Disconnects all agents from each other briefly and then reconnects.

Running databases aren't affected by this operation. After the operation completes, you might need to update the standby priority list. See the efm set-priority command for more information.

efm resume

efm resume <cluster_name>

Invoke the efm resume command to resume monitoring a previously stopped database. This command must be invoked by efm, a member of the efm group, or root.

efm set-priority

efm set-priority <cluster_name> <address> <priority>

Invoke the efm set-priority command to assign a failover priority to a standby node. The value specifies the order in which to use the node in the event of a failover. This command must be invoked by efm, a member of the efm group, or root.

Use the priority option to specify the place for the node in the priority list. For example, specify a value of 1 to indicate that the node is the primary standby and will be the first node promoted in the event of a failover. A priority value of 0 instructs Failover Manager not to promote the standby.

efm stop-cluster

efm stop-cluster <cluster_name>

Invoke the efm stop-cluster command to stop Failover Manager on all nodes. This command instructs Failover Manager to connect to each node on the cluster and instruct the existing members to shut down. The command has no effect on running databases, but when the command completes, there's no failover protection in place.

This command must be invoked by efm, a member of the efm group, or root.

efm upgrade-conf

efm upgrade-conf <cluster_name> [-source <directory>]

Invoke the efm upgrade-conf command to copy the configuration files from an existing Failover Manager installation and add parameters required by a Failover Manager installation. Provide the name of the previous cluster when invoking the utility. This command must be invoked with superuser privileges if you're running Failover Manager in the default mode.

For information on the optional -source flag, or if you're upgrading from a Failover Manager configuration that doesn't use sudo, see Upgrading Failover Manager.

efm node-status-json

efm node-status-json <cluster_name>

Invoke the efm node-status-json command to display the status of a local node in JSON format. A successful execution of this command returns 0 as its exit code. In case of a database failure or an agent status becoming IDLE, the command returns 1 as exit code.

The following is an example output of the efm node-status-json command:

{
  "type":"Standby",
  "address":"172.16.144.130",
  "db":"UP",
  "vip":"",
  "vip_active":"false"
 }

efm --help

efm --help

Invoke the efm --help command to display online help for the Failover Manager utility commands.