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Physical Memory Alarm #4065

MFalkner ·

Since I've updated to QB9, I frequently get alarms on physical memory from my agents in the grid:
Memory High Usage Physical Memory :: Memory Usage=93.03%
The system alarm is defined as Physical Memory :: Memory Usage > 85.00% at each time the condition is true.

Most of my agent run on a virtual Windows 7 32-bit machine with 1.5GB of physical memory.
I tried to make sense out of this, but the longer I look into this the more I get confused.

On the Grid page for this node I see:
CPU: 2.5 GHz GenuineIntel / 1 processors
Memory: 1GB
Swap: 1GB
JVM Memory Max: 495MB
JVM Heap Max: 495MB

So how does this relate to the 1.5GB memory the machine was allocated to?

Further, the metrics show a memory usage of between 11% and 22%, dropping from 22% to 11% every 30 minutes. However, on the machines task manager, the memory usage is shown as approx. 1GB of the 1.5GB what makes 66%. Again, how does this relate?

Does anybody have some insight on this?
As I did not see this alarms with QB8, did anything change in this area?

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steveluo ADMIN ·

Hi@MFalkner

First, on Grid Page, the memory is physical memory, but the memory usage is for JVM memory usage. So your physical memory is 1GB while JVM memory is about 495MB.

Second, the JVM memory usage is between 11% and 22%, that is not physical memory usage which you saw on machine task manager.

steveluo ADMIN ·

By the way, we do change metrics collection lib from sigar to oshi due to sigar hasn't updated for a long time and does not support JDK11.

MFalkner ·

Hi Steve,
Thank you for this very detailed answer. However, I'm still not satisfied with what I'm seeing.
The Grid page shows 1GB of physical memory, but the machine has 1.5GB of memory, could this just be a display / bad rounding problem?
The original questions was, why do I suddenly get those alarms I did not have with QB8. According to the output, it's physical memory and this is clearly what I see in task manager. Could this be related to the wrong display of physical memory in the Grid?
BTW: I changed the alarm to report only if it occurs 2 times consecutively, but even less, I still get them. But looking at the real machine on at the same time, I do not see this high increase.
Regards, Martin

steveluo ADMIN ·

Hi@MFalkner

I have tested with Windows 10 64bit, but don't see this issue. The physical memory is correct. Is this only for Windows 7 32bit machine or also occurred on other machines?

According to your alarm definition, I want to know whether the machine you said is the server or agent? The alarm you mentioned is for server only.

MFalkner ·

Hi Steve,

Interesting what you are saying.
It occurs only on machines that have 1.5G of memory and those are all Windows 7 32-bit. Other machines, whether they are Windows 7 or 10 do not have this problem. However, they all have physical memory that is a multiple of 1G, so I think the 1.5G is just a display problem.

As for the alarm: The alarm is from an Agent. In the System Alert Plugin I could limit it to server only, but why would I, as it worked with QB8 perfectly. And where does it say it's for server only?
Martin

steveluo ADMIN ·
MFalkner ·

Hi Steve,
I just updated to the latest version, thanks you.
Very nice chart, even with scale labels!
I'll monitor the memory and let you know what will happen.
Thanks, Martin