Previous topic |
Next topic |
Contents |
Contact z/OS |
Library |
PDF
Checking global resource serialization (GRS) resource contention z/OS DFSMStvs Planning and Operating Guide SC23-6877-00 |
|
To check GRS resource contention by displaying GRS enqueues and latch usage
on all machines in the sysplex, issue either of the following MVS™ commands, as
shown in Figure 1:
Figure 1. Examples of DISPLAY GRS commands
A normal response looks like one shown in Figure 2:
Figure 2. Example of a normal response from a DISPLAY GRS command
A response showing GRS contention is shown in Figure 3:
Figure 3. Example
of a GRS command showing contention
This example shows which tasks have exclusive enqueues on the log streams and which tasks are waiting for them. It is quite normal for enqueues and latches to be obtained, occasionally with contention. They are indications of a problem only when they last for more than a minute or so. Long term enqueuing on the SYSZLOGR resource can be a sign of problems even if there is no contention. You can choose to display only those log streams exclusively enqueued on,
or being waited on, by DFSMStvs jobs in the sysplex. Issue the MVS command shown
in Figure 4:
Figure 4. Example of a GRS command to display log streams with an exclusive enqueue
A typical response to this command looks like the example in Figure 5:
Figure 5. Example of output from a GRS command to display log streams with an exclusive
enqueue
|
Copyright IBM Corporation 1990, 2014
|