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Questions tagged [jfr]

JRockit/Java/JDK Flight Recorder (JFR), a performance monitoring and profiling tool

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Where can I download Java Mission Control(7) (OpenJDK11 or higher)?

Java Mission Control(JMC) was announced to be handed over from Oracle to the open source community from JDK 11 onwards. However JMC is not bundled with the OpenJDK11 releases. I read that JMC will be provided as separate download here, but there are…
Simulant
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Java Mission Control (JMC) 6.0 does not show hot methods when examining a JFR flight recording

After using the Java Flight Recording functionality on a running application, Java's JMC could be used to examine the resulting JFR file to show hot methods, and a percentage of CPU time spent in each method. This was very useful for profiling…
Andrew Parks
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Monitoring Locks with Java Flight Recorder and Java Mission Control

What I want to do I have a Java program which I am trying to improve. I suspect synchronized blocks within the code to hurt performance but I would like to make sure this is my problem before touching my code. How I went on about it To check if…
Patrick
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Java Mission Control Heap Profile

I am playing with the new Java Mission Control Profiler that is coming with the Java 7u40 and I cannot make it to profile allocation and collect object statistics. No matter what I do, I cannot see any statistics in the Memory -> Object Statistics…
Aleš
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Java Flight Recorder comprehensive list of VM options for OpenJDK 8 & OpenJDK 11

Is there a way to get a comprehensive list of VM options for Java Flight Recorder (JFR). I am particularly interested in OpenJdk 8 & OpenJdk 11 so far I find this list quite usefull https://chriswhocodes.com/hotspot_options_jdk8.html also java…
Marcin Wasiluk
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Java Flight Recorder - Continuous rolling recording

Question How to get a rolling recording into disk, with a maximum age? Context When something goes bad in my server, I want to be able to dump the profiling information of the hours prior and analyse it, to know what went wrong. As I don't know…
cmhteixeira
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How to use Java 11 Java Flight Recorder JFR library with Wildfly 16

Background I'm working on jboss/wildfly 16 servlet mypackagex.war. It's a maven project. My server uses openjdk11-jdk. I managed to run the produce a java flight recording using jcmd. And managed to open that jfr dump with JDK Mission Control. All…
RonPringadi
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How to record allocations with JFR on command line?

I have a profile I've created with Java Mission Control that has allocation profiling enabled. When I used it from the JMC UI to record, everything works fine and I get the results. However, after exporting the settings and trying to record with JFR…
jmiettin
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How to avoid truncated stack traces with Java Flight Recorder

I am using Oracle Java Flight Recorder to collect stack trace samples of a Java application. Theses stack traces allows me to eventually produce a CPU Flamegraph. My issue is that stack traces deeper than 64 frames are truncated by Java Flight…
Clément MATHIEU
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how to profile blocking code in java – measure execution time instead of CPU time

I am trying to profile that is often blocking in either database and rest calls. The code is not cpu bound. The following sample junit methods should illustrate the issue: @RepeatedTest(10) void fast() throws InterruptedException { …
bollin
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How to profile the number of exceptions generated, categorized by exception class or line of code

I'm using a number of open-source third-party libraries, and a flight recording shows that the code is generating tens of thousands of exceptions per second. How can I track down which type of exception is being thrown, and where in the source code…
Andrew Parks
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How to include IO-bound methods in Java Flight Recorder sampling?

I'm starting JFR at launch by specifying the following CLI options to the Java program under test: -Xmx24g -XX:+UnlockCommercialFeatures -XX:+FlightRecorder -XX:FlightRecorderOptions=defaultrecording=true,dumponexit=true,settings=profile The test…
Alex R
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How to enable Object Statistics in JFR?

I'm testing my Java code with filghtrecorder, all other data sees good(they shows sth.), but the "Memory -> Object Statistics" is empty. Using JDK 1.8.0_161 Here is the parameter I used. java -XX:+UnlockCommercialFeatures -XX:+FlightRecorder…
Zhang Yunlu
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How to import lib for JMX and Java mission Control?

Two questions I am having are: How to Import lib for jmx(i can't import it)? Can we access Java Mission Control using Code? (like I can see the visualisation of my problem but I want to fetch it into my IDE using code), is it possible?
Coder
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Java Flight Recorder application method start and end time

I'm interested in whether it is possible to get start and end time in nanoseconds for every or most of user methods in profiling with JFR program? I know that it is possible to do with code instrumentation, but I would like to leverage advantage of…
user2529617
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