Difference between revisions of "Java"

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(OpenJDK Heapdump)
(GC)
Line 17: Line 17:
 
* http://mechanical-sympathy.blogspot.co.uk/2013/07/java-garbage-collection-distilled.html
 
* http://mechanical-sympathy.blogspot.co.uk/2013/07/java-garbage-collection-distilled.html
 
* http://www.oracle.com/technetwork/java/javase/gc-tuning-6-140523.html
 
* http://www.oracle.com/technetwork/java/javase/gc-tuning-6-140523.html
 +
 +
sudo jmap -heap <pid>
  
 
  java \
 
  java \
Line 26: Line 28:
 
   -XX:+CMSIncrementalMode \
 
   -XX:+CMSIncrementalMode \
 
   -XX:+CMSIncrementalPacing \
 
   -XX:+CMSIncrementalPacing \
 +
 +
java \
 +
  -verbose:gc \
 +
  -XX:+PrintGCDetails \
 +
  -XX:MaxGCPauseMillis=20 \
 +
  -XX:MaxGCMinorPauseMillis=10 \
 +
  -XX:GCTimeRatio=200 \
 +
  -XX:ParallelGCThreads=2 \
 +
  -Xms140m -Xmx140m \

Revision as of 04:19, 4 March 2014

OpenJDK Heapdump

sudo yum install java-1.6.0-openjdk-devel
sudo jmap -F -J-d64 -dump:live,format=b,file=/root/heap.bin 2232
sudo jstack -F 2232 > /root/stacks.txt

Remote Debug Tomcat6

In /usr/sbin/tomcat6:

-Xdebug -Xrunjdwp:transport=dt_socket,address=62277,server=y,suspend=n

GC

sudo jmap -heap <pid>
java \
  -Xms300m \
  -Xmx600m \
  -verbose:gc \
  -XX:MaxGCPauseMillis=20 \
  -XX:+UseConcMarkSweepGC \
  -XX:+CMSIncrementalMode \
  -XX:+CMSIncrementalPacing \
java \
  -verbose:gc \
  -XX:+PrintGCDetails \
  -XX:MaxGCPauseMillis=20 \
  -XX:MaxGCMinorPauseMillis=10 \
  -XX:GCTimeRatio=200 \
  -XX:ParallelGCThreads=2 \
  -Xms140m -Xmx140m \