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| How the agent makes Sybase highly available | ||
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| Prev | Introducing the Cluster Server Agent for Sybase | Next |
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| How the agent makes Sybase highly available | ||
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| Prev | Introducing the Cluster Server Agent for Sybase | Next |
The Cluster Server agent for Sybase continuously monitors the Sybase database and SybaseBk processes to verify whether they function properly.
The agent for Sybase can perform different levels of monitoring and different actions which you can configure.
Primary or Basic monitoring: In the basic monitoring mode, the agent monitors the configured Sybase server process, and fails over or restarts the group during an application failure.
Detail monitoring: In the optional detail monitoring mode, the agent detects application failure if it cannot perform a transaction in the test table in the Sybase database server.
Intelligent monitoring framework (IMF): The Sybase agent is IMF-aware and uses asynchronous monitoring framework (AMF) kernel driver for resource state change notifications.
See How the Sybase and SybaseBk agents support intelligent resource monitoring .
For Sybase cluster edition, the agent uses the Sybase-provided utility, qrmutil, to know if the status of the instance is up or down. If qrmutil reports the status as failure pending, the agent reboots the node and the instance is automatically started again.
When the Sybase agent detects that the configured Sybase server is not running on a system, based on the value of OnlineRetryLimit attribute of the Sybase server group, the service group is restarted on the same system on which the group faulted.
For ASE Enterprise edition when the agent detects that the configured Sybase server is not running on a system, the Sybase service group is failed over to the next available system in the service group's SystemList. The configured Sybase servers are started on the new system, thus ensuring high availability for the Sybase server and data.