Tuning InternalLogbufferSize

Begin with the default value. Look out for HIGH LOAD informational messages in the history files. The relevant messages contain nilog, and a description of the internal resource contention that occurred.

Use the following command to display node internal log buffer information:

hadbm resourceinfo --nilogbuf

For example, the output might look something like this:

Node No.     Avail         Free Size
0            11            11
1            11            11

To change the size of the nilog buffer, use the following command:

hadbm set InternalLogbufferSize

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 Java System Application Server Enterprise Edition 8.2 High Availability Administration Guide.

If the size of the nilog buffer is changed, the associated log device (located in the same directory as the data devices) also changes. The size of the internal log buffer must be equal to the size of the internal log device. The command hadbm set InternalLogBufferSize ensures this requirement. It stops a node, increases the InternalLogBufferSize, re initializes the internal log device, and brings up the node. This sequence is performed on all nodes.