Sun Microsystems 820434310 manual Timeouts, Jdbc connection pool timeouts, Load Balancer timeouts

Tuning HADB

For example, the output displayed by this command might look something like this:

Node No.	Avail	Free	Waits
0	50000	50000	na
1	50000	50000	na

■Avail: Number of locks available.

■Free: Number of locks in use.

■Waits: Number of transactions that have waited for a lock.“na” (not applicable) if all locks are available.

To change the number of locks, use the following command:

hadbm set NumberOfLocks

The hadbm restarts all the nodes, one by one, for the change to take effect. For more information on using this command, see “Configuring HADB” in Sun GlassFish Enterprise Server 2.1 High Availability Administration Guide.

Timeouts

This section describes some of the timeout values that affect performance.

JDBC connection pool timeouts

These values govern how much time the server waits for a connection from the pool before it times out. In most cases, the default values work well. For detailed tuning information, see “Tuning JDBC Connection Pools” on page 77.

Load Balancer timeouts

Some values that may affect performance are:

■response-timeout-in-seconds -The time for which the load balancer plug-in will wait for a response before it declares an instance dead and fails over to the next instance in the cluster. Make this value large enough to accommodate the maximum latency for a request from the server instance under the worst (high load) conditions.

■health checker: interval-in-seconds - Determines how frequently the load balancer pings the instance to see if it is healthy. Default value is 30 seconds. If the response-timeout-in-seconds is optimally tuned, and the server doesn’t have too much traffic, then the default value works well.

■health checker: timeout-in-seconds - How long the load balancer waits after “pinging” an instance. The default value is 100 seconds.

The combination of the health checker’s interval-in-seconds and timeout-in-seconds values determine how much additional traffic goes from the load balancer plug-in to the server instances.

Chapter 6 • Tuning for High-Availability 115