websphere probe internal used memory alarm

Products

• DX Unified Infrastructure Management (Nimsoft / UIM)
• CA Unified Infrastructure Management On-Premise (Nimsoft / UIM)

Issue/Introduction

The probe internal used memory 518784 KB (101 %) >= 100.0 % of 512000 KB (High Memory threshold)

.

Environment

Release : Any supported UIM version

Component : UIM - WEBSPHERE

websphere probe v1.74/1.82

 

Cause

- configured memory limits

Resolution

websphere internal used memory alarms

The websphere alarm is controlled by the memoryLimitLow and memoryLimitHigh settings in the probe.

The probe is creating a child process for monitoring but the child process does not have any heap space setting. The child process (it is also a jvm) is allowed to use 1/64 of system memory because it does not have a heap setting. Therefore, if your server has 32GB RAM, then the child process is allowed to use up to 512MB. 
However, the websphere probe has an internal memory usage limit in the probe, so it raises the alarm.

Control JVM Heap Memory Size
You can create keys to control value of the heap memory size that is used while running the probe. The heap is the area where the Java objects reside. The heap size impacts the JVM performance and thus, the performance of Java application. Setting the heap size gives you a controlled environment where you get a good heap size right from the start.

Follow these steps, as an example: 

- Select the probe in the IM and press the Shift key.
- Right-click and select Raw Configure.
- The Raw Configure dialog appears.
- You can also select Raw Configure from the Admin Console.
- Select properties in the left pane and click New Section button.
- The New Section dialog appears.
- Enter the section name as java_options and click OK.
- The java_options folder is created under properties folder.
- Select the java_options folder and click New Key.
- The New Key dialog appears.
- Enter the first key name as min and value as -Xms512m
- The min key is created. The key defines the value of initial and minimum heap memory sizes to be used by the probe.
- Enter the second key name as max and value as -Xmx1024m
- The max key is created. The key defines the value of the maximum heap memory size to be used by the probe.
- Click the Apply button and run the probe again.
- The probe uses the set limit for heap size.

Set the -Xmx to a value which is higher than the number reported in the alarm.

Also, right now you websphere memory limits under the websphere.cfg setup section shows:

<setup>
    loglevel = 5
    logsize = 20000
    <memory>
        memoryLimitLow = 256000
        severityhigh = 3
        severitylow = 2
        memoryLimitHigh = 512000
    </memory>
</setup>

So please change that to:

<setup>
    loglevel = 3
    logsize = 5000
    <memory>
        memoryLimitLow = 1024000
        severityhigh = 3
        severitylow = 2
        memoryLimitHigh = 2048000
    </memory>
</setup>

Then Deactivate-Activate the websphere probe.

Check the log to  make sure its free of any memory-related errors.