Administration guide > Tune and performance



Configure failover detection

You can configure the amount of time between system checks for failed servers with the heartbeat interval setting.

Configure failover varies depending on the type of environment you are using. If you are using a stand-alone environment, you can configure failover with the command line. If you are using a WAS ND environment, configure failover in the WAS ND administrative console.


Procedure


What to do next

When these settings are modified to provide short failover times, there are some system-tuning issues to be aware of. First, Java is not a real-time environment. It is possible for threads to be delayed if the JVM is experiencing long garbage collection times. Threads might also be delayed if the machine hosting the JVM is heavily loaded (due to the JVM itself or other processes running on the machine). If threads are delayed, heartbeats might not be sent on time. In the worst case, they might be delayed by the required failover time. If threads are delayed, false failure detections occur. The system must be tuned and sized to ensure that false failure detections do not happen in production. Adequate load testing is the best way to ensure this.

The current version of eXtreme Scale supports WebSphere Real Time.


Parent topic:

Configure deployment policies


Parent topic:

Tune and performance


Related concepts

Operating systems and network tuning

Plan for network ports

ORB properties and file descriptor settings

JVM tuning for WebSphere eXtreme Scale

Use WebSphere Real Time


Related tasks

Controlling shard placement with zones

Tune the dynamic cache provider

Tune the cache sizing agent for accurate memory consumption estimates

Related reference

Configure distributed deployments

Deployment policy descriptor XML file

deploymentPolicy.xsd file

Operational checklist