Sun Cluster HA for Netscape LDAP Fault Probes

The Sun Cluster HA for Netscape LDAP local probe can perform a variable number of local restarts before initiating a failover. The local restart mechanism uses a sliding window algorithm; only when the number of retries is exhausted within that window does a failover occur.

The Sun Cluster HA for Netscape LDAP remote probe uses a simple telnet connection to the LDAP port to check the status of the server. The LDAP port number is the one specified during initial set-up with hadsconfig(1M).

The local probe:

• Probes the server by running a monitoring script. The script performs a search for the LDAP common name "monitor." The common name is defined by the Directory Server and is used only for monitoring. The probe uses the ldapsearch utility to perform this operation.

• Tries to restart the server locally, upon detecting a problem with the server.

• Initiates the hactl(1M) command in the giveup mode upon deciding that the local node cannot reliably run the directory server instance, while the remote probe initiates the hactl(1M) command in the takeover mode. If there are multiple possible masters of the logical host, all of the remote probes invoke the takeover operation in unison. However, after the takeover, the underlying framework ensures that a unique master node is chosen for the Directory Server.