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new d6778b3 [FLINK-14038][docs] Extend Application Profiling documentation
d6778b3 is described below
commit d6778b3b95d1e72664b9e6f24b65420054816023
Author: Till Rohrmann <[email protected]>
AuthorDate: Thu Feb 20 19:00:37 2020 +0100
[FLINK-14038][docs] Extend Application Profiling documentation
This commit adds explanations on how to analyze/debug out of memory
problems and
how to analyze GC behaviour.
This closes #11165.
---
docs/monitoring/application_profiling.md | 34 ++++++++++++++++++++++++++---
docs/monitoring/application_profiling.zh.md | 32 +++++++++++++++++++++++++--
2 files changed, 61 insertions(+), 5 deletions(-)
diff --git a/docs/monitoring/application_profiling.md
b/docs/monitoring/application_profiling.md
index 2a3feea..3fe0adb 100644
--- a/docs/monitoring/application_profiling.md
+++ b/docs/monitoring/application_profiling.md
@@ -1,5 +1,5 @@
---
-title: "Application Profiling"
+title: "Application Profiling & Debugging"
nav-parent_id: monitoring
nav-pos: 15
---
@@ -33,7 +33,7 @@ user in `env.java.opts`, `env.java.opts.jobmanager`,
`env.java.opts.taskmanager`
use of the script variable `FLINK_LOG_PREFIX` and by enclosing the options in
double quotes for late evaluation. Log files
using `FLINK_LOG_PREFIX` are rotated along with the default `.out` and `.log`
files.
-# Profiling with Java Flight Recorder
+## Profiling with Java Flight Recorder
Java Flight Recorder is a profiling and event collection framework built into
the Oracle JDK.
[Java Mission
Control](http://www.oracle.com/technetwork/java/javaseproducts/mission-control/java-mission-control-1998576.html)
@@ -44,7 +44,7 @@ Flight Recorder. Example configuration:
env.java.opts: "-XX:+UnlockCommercialFeatures -XX:+UnlockDiagnosticVMOptions
-XX:+FlightRecorder -XX:+DebugNonSafepoints
-XX:FlightRecorderOptions=defaultrecording=true,dumponexit=true,dumponexitpath=${FLINK_LOG_PREFIX}.jfr"
{% endhighlight %}
-# Profiling with JITWatch
+## Profiling with JITWatch
[JITWatch](https://github.com/AdoptOpenJDK/jitwatch/wiki) is a log analyser
and visualizer for the Java HotSpot JIT
compiler used to inspect inlining decisions, hot methods, bytecode, and
assembly. Example configuration:
@@ -53,4 +53,32 @@ compiler used to inspect inlining decisions, hot methods,
bytecode, and assembly
env.java.opts: "-XX:+UnlockDiagnosticVMOptions -XX:+TraceClassLoading
-XX:+LogCompilation -XX:LogFile=${FLINK_LOG_PREFIX}.jit -XX:+PrintAssembly"
{% endhighlight %}
+## Analyzing Out of Memory Problems
+
+If you encounter `OutOfMemoryExceptions` with your Flink application, then it
is a good idea to enable heap dumps on out of memory errors.
+
+{% highlight yaml %}
+env.java.opts: "-XX:+HeapDumpOnOutOfMemoryError
-XX:HeapDumpPath=${FLINK_LOG_PREFIX}.hprof"
+{% endhighlight %}
+
+The heap dump will allow you to analyze potential memory leaks in your user
code.
+If the memory leak should be caused by Flink, then please reach out to the
[dev mailing list](mailto:[email protected]).
+
+## Analyzing Memory & Garbage Collection Behaviour
+
+Memory usage and garbage collection can have a profound impact on your
application.
+The effects can range from slight performance degradation to a complete
cluster failure if the GC pauses are too long.
+If you want to better understand the memory and GC behaviour of your
application, then you can enable memory logging on the `TaskManagers`.
+
+{% highlight yaml %}
+taskmanager.debug.memory.log: true
+taskmanager.debug.memory.log-interval: 10000 // 10s interval
+{% endhighlight %}
+
+If you are interested in more detailed GC statistics, then you can activate
the JVM's GC logging via:
+
+{% highlight yaml %}
+env.java.opts: "-Xloggc:${FLINK_LOG_PREFIX}.gc.log
-XX:+PrintGCApplicationStoppedTime -XX:+PrintGCDetails -XX:+PrintGCDateStamps
-XX:+UseGCLogFileRotation -XX:NumberOfGCLogFiles=10 -XX:GCLogFileSize=10M
-XX:+PrintPromotionFailure -XX:+PrintGCCause"
+{% endhighlight %}
+
{% top %}
diff --git a/docs/monitoring/application_profiling.zh.md
b/docs/monitoring/application_profiling.zh.md
index c766164..6061f21 100644
--- a/docs/monitoring/application_profiling.zh.md
+++ b/docs/monitoring/application_profiling.zh.md
@@ -33,7 +33,7 @@ user in `env.java.opts`, `env.java.opts.jobmanager`,
`env.java.opts.taskmanager`
use of the script variable `FLINK_LOG_PREFIX` and by enclosing the options in
double quotes for late evaluation. Log files
using `FLINK_LOG_PREFIX` are rotated along with the default `.out` and `.log`
files.
-# Profiling with Java Flight Recorder
+## Profiling with Java Flight Recorder
Java Flight Recorder is a profiling and event collection framework built into
the Oracle JDK.
[Java Mission
Control](http://www.oracle.com/technetwork/java/javaseproducts/mission-control/java-mission-control-1998576.html)
@@ -44,7 +44,7 @@ Flight Recorder. Example configuration:
env.java.opts: "-XX:+UnlockCommercialFeatures -XX:+UnlockDiagnosticVMOptions
-XX:+FlightRecorder -XX:+DebugNonSafepoints
-XX:FlightRecorderOptions=defaultrecording=true,dumponexit=true,dumponexitpath=${FLINK_LOG_PREFIX}.jfr"
{% endhighlight %}
-# Profiling with JITWatch
+## Profiling with JITWatch
[JITWatch](https://github.com/AdoptOpenJDK/jitwatch/wiki) is a log analyser
and visualizer for the Java HotSpot JIT
compiler used to inspect inlining decisions, hot methods, bytecode, and
assembly. Example configuration:
@@ -53,4 +53,32 @@ compiler used to inspect inlining decisions, hot methods,
bytecode, and assembly
env.java.opts: "-XX:+UnlockDiagnosticVMOptions -XX:+TraceClassLoading
-XX:+LogCompilation -XX:LogFile=${FLINK_LOG_PREFIX}.jit -XX:+PrintAssembly"
{% endhighlight %}
+## Analyzing Out of Memory Problems
+
+If you encounter `OutOfMemoryExceptions` with your Flink application, then it
is a good idea to enable heap dumps on out of memory errors.
+
+{% highlight yaml %}
+env.java.opts: "-XX:+HeapDumpOnOutOfMemoryError
-XX:HeapDumpPath=${FLINK_LOG_PREFIX}.hprof"
+{% endhighlight %}
+
+The heap dump will allow you to analyze potential memory leaks in your user
code.
+If the memory leak should be caused by Flink, then please reach out to the
[dev mailing list](mailto:[email protected]).
+
+## Analyzing Memory & Garbage Collection Behaviour
+
+Memory usage and garbage collection can have a profound impact on your
application.
+The effects can range from slight performance degradation to a complete
cluster failure if the GC pauses are too long.
+If you want to better understand the memory and GC behaviour of your
application, then you can enable memory logging on the `TaskManagers`.
+
+{% highlight yaml %}
+taskmanager.debug.memory.log: true
+taskmanager.debug.memory.log-interval: 10000 // 10s interval
+{% endhighlight %}
+
+If you are interested in more detailed GC statistics, then you can activate
the JVM's GC logging via:
+
+{% highlight yaml %}
+env.java.opts: "-Xloggc:${FLINK_LOG_PREFIX}.gc.log
-XX:+PrintGCApplicationStoppedTime -XX:+PrintGCDetails -XX:+PrintGCDateStamps
-XX:+UseGCLogFileRotation -XX:NumberOfGCLogFiles=10 -XX:GCLogFileSize=10M
-XX:+PrintPromotionFailure -XX:+PrintGCCause"
+{% endhighlight %}
+
{% top %}
