unusual gaps at the tread overview

Questions about YourKit Java Profiler
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ChristianB
Posts: 2
Joined: Thu Sep 01, 2016 8:20 am

unusual gaps at the tread overview

Post by ChristianB »

Hallo,

sometimes our application is slowing down and we are seeing unusual gaps at the thread overview:
Image
We have seen this before caused by gc activity. But this time it must be something different.
We have checked at the gc log PrintGCApplicationStoppedTime and we cannot see these gaps there.

Also we are seeing a lot of time consumption at com.yourkit.probes which we have not seen before:
Image

Any idea what can cause these gaps and our performance problem?
We are running at Java 1.7 45 and with a JBoss 5.0
Anton Katilin
Posts: 6172
Joined: Wed Aug 11, 2004 8:37 am

Re: unusual gaps at the tread overview

Post by Anton Katilin »

Hi,

The gaps indicate that the telemetry was obtained less frequently than with the default 1 second period because JVM did not let the telemetry thread run as soon as it requested. Most likely this was related with GC pauses or with CPU activity in other threads of the application.

Please check the tab "Memory", "Memory & GC Telemetry" view, garbage collection related graphs. Do you see spikes?

How many threads does the application have?

Best regards,
Anton
ChristianB
Posts: 2
Joined: Thu Sep 01, 2016 8:20 am

Re: unusual gaps at the tread overview

Post by ChristianB »

Hi Anton,

in the tabs "Memory" i dont see any unusal data:
Image
There are only a few gc-spikes with less then 400 ms.
We have checked with the gc log and we cannot see the application pauses there.

The application has about 250 Threads. But must of them are "waiting" when that behavior occured. It was not a high-load situation.
Anton Katilin
Posts: 6172
Joined: Wed Aug 11, 2004 8:37 am

Re: unusual gaps at the tread overview

Post by Anton Katilin »

Could you please send the following files to [email protected] :

- the profiler agent log file <user home>/.yjp/log/<session name>-<pid>.log

- the snapshot file (.snapshot)
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