A heartbeat in Geographic Edition is a container for a collection of heartbeat plug-ins. A heartbeat has a name and one property that you can tune, Query_interval. The Query_interval property specifies the delay between heartbeat status requests.
The heartbeat plug-in facilitates the actual physical monitoring activity. The plug-in is defined by a required query command or query library, an optional requester and responder agent, a type, and a Plugin_properties string.
The Geographic Edition framework provides a default heartbeat and default heartbeat plug-ins. You can also create a custom heartbeat or a custom heartbeat plug-in.
This section provides the following information:
A default heartbeat that uses the default heartbeat plug-ins is created every time you run geops create or geops join without specifying a custom heartbeat. The name of the default heartbeat is hb_local-cluster-name~remote-partner-cluster-name. For more information about the geops command, refer to the geops(1M) man page.
The Geographic Edition product provides the following default plug-ins:
tcp_udp_plugin - Performs a simple heartbeat check on the cluster logical host IP address. If tcp_udp_plugin cannot use UDP port 2084, the plug-in tries to use TCP port 2084.
ping_plugin - Pings the cluster logical hostname on the remote cluster.
You can create a custom heartbeat plug-in to configure with the default heartbeat or with a new custom heartbeat.
When a heartbeat is created with a custom heartbeat plug-in, the custom heartbeat plug-in is passed the following arguments by the Geographic Edition framework:
The value of the Query_interval property, which defines the delay in seconds after which a heartbeat status request is declared a failure.
The mode for the plug-in startup, either Normal or Emergency.
The value of the Plugin_properties property that is configured for the heartbeat plug-in, if any.
For more information about the properties you can set, see Standard Geographic Edition Properties.
The custom heartbeat plug-in is expected to check the heartbeat on the secondary cluster and return one of the following exit values:
Zero, if successful – Indicates that the secondary cluster is alive
Nonzero, on failure – Indicates that the secondary cluster did not respond to the heartbeat check
Observe the following guidelines when you create custom heartbeats:
The ability to create custom heartbeats is provided for special circumstances. They require careful configuration. Consult your Oracle specialist for assistance if your system requires the use of custom heartbeats.
Create the custom heartbeat before you create a partnership. If you create a partnership before you create the custom heartbeat, the default heartbeat that is used by the partnership will prevent the custom heartbeat from being created.
Ensure that the name of your custom heartbeat is different from the name of the custom heartbeat on the partner cluster.
Add at least one plug-in to the custom heartbeat, to prevent the partnership from remaining in degraded mode.
A custom heartbeat prevents the default heartbeat from being used during partnership creation. If you want to use the default heartbeat for your partnership, you must delete the custom heartbeat before you create the partnership with the geops create command.