About this task
Use Recent Activity when you need to investigate potential
memory problems relating to garbage collection and the JVM heap size.
Sometimes, garbage collection might not clean up properly or the heap
can have too little memory allocated.
To create a Recent
Activity report:
Procedure
- From the top navigation, click Availability > Recent
Activity Display.
The Recent Activity Display page
opens.
- Select a group and a server from the lists.
- For Metric 1 and Metric 2, select the two metrics that
you want to compare from the lists.
The available metrics
are as follows:
- # of Requests
- Avg. Response Time
- Live Sessions
- System Paging Rate
- JVM CPU
- JVM Heap Size
- # of GCs
- Total GC Time
- Avg. Heap Size after GC
Note: The Garbage Collection options are not supported for either CICS® or IMS.
When the date range is Last 48 Hours,
the Avg. Response Time value equals the result of the summary of AVG_RES_TIME
in this hour divided by the summary counts of AVG_RES_TIME in this
hour. If no AVG_RES_TIME occurs within the hour then the result is
0. When the date range is Last 60 Minutes, the Avg. Response Time
value equals the result of the summary of AVG_RES_TIME in this minutes
divided by the summary count of AVG_RES_TIME in this minute. If no
AVG_RES_TIME occurs within the minute then the result is 0.
- For Time, select the time when you want the system to extract
the data.
- Click the OK button.
A
new report displays based on your selection. You can click the bars
in the graph for further details.
- Using the Recent Activity Options, you can select a different
group or server, compare two different metrics, or view a different
time increment.
Results
Either heap size or garbage collection can cause a slow
down in the performance of your server. Check if the heap size is
too small for the number of users using the system or too small for
the current workload on the system. At times, garbage collection can
cause high JVM CPU usage, slow transaction response time, or a delay
on the throughput. Analyze the memory in your system using the Recent
Activity Display and then make the necessary adjustments.