Java.txt

java -classpath jarfilelocation classname
java -classpath "C:\Program Files\IBM\SDP\runtimes\base_v7\java\jre\lib\xml.jar" org.apache.xalan.Version
java -cp "C:\Program Files\IBM\SDP\runtimes\base_v7\java\jre\lib\xml.jar" org.apache.xalan.Version

--JVM troubleshooting tool 
jinfo -flag MaxPermSize 5144
 
jvisualvm
jvisualvm --console new 
 
jstat -gc 5612 5s -- Seconds
jstat -gc 5612 5ms --milli seconds
jstat -gcutil 6436
jstat -gcutil 6436 250 7 --  7 samples at 250 millisecond intervals
jstat -gcnew -h3 6436 250 --  output the column header after every 3 lines of data. 
jstat -gcutil -t 6436 250 3 -- 3 samples at 250 millisecond intervals with timestamp

--to get the process ID (pid) 
jps -mlvV
jps -m

-- To find PermGen leaks
jmap -heap 5144
jmap -permstat 18254 > permstats_2.txt
jmap -histo:live 18254 > histo_live.txt
jmap -histo 18254 > histo.txt
jmap -dump:format=b,file=leak 3144 
jmap -finalizerinfo
jmap -histo:live 5612 | more

-- Trace loading of classes.
-XX:-TraceClassLoading 

--Trace unloading of classes.
-XX:-TraceClassUnloading 

--  Trace all classes loaded in order referenced (not loaded).
-XX:-TraceClassLoadingPreorder

-- Trace constant pool resolutions. (Introduced in 1.4.2.)
-XX:-TraceClassResolution 

-- To read heap dump
jhat -J-Xmx512m leak 

jconsole 5144

--Temporary Solution  for OutOfMemoryError PermGen Space Error
-XX:+UseConcMarkSweepGC
-XX:+CMSPermGenSweepingEnabled -- deprecated
-XX:+CMSClassUnloadingEnabled

-XX:PermSize=256M
-XX:MaxPermSize=512M

-XX:+HeapDumpOnOutOfMemoryError
-XX:HeapDumpPath=E:/log

-- IBM heap analyser tool
java –Xmx1000m –jar ha135.jar

-- Output GC to file each time it runs
-verbose:gc 
-XX:+PrintGCDetails
-XX:+PrintGCTimeStamps
-Xloggc:E:/log/gc.log

-XX:-DisableExplicitGC - By default calls to System.gc() are enabled (-XX:-DisableExplicitGC). Use -XX:+DisableExplicitGC to disable calls to System.gc(). Note that the JVM still performs garbage collection when necessary.
-XX:+UseConcMarkSweepGC - Use concurrent mark-sweep collection for the old generation. (Introduced in 1.4.1)
-XX:+UseParallelGC - Use parallel garbage collection for scavenges. (Introduced in 1.4.1)
-XX:+UseParallelOldGC - Use parallel garbage collection for the full collections. Enabling this option automatically sets -XX:+UseParallelGC. (Introduced in 5.0 update 6.)
-XX:+UseSerialGC - Use serial garbage collection. (Introduced in 5.0.)

-server
-Xms512m
-Xmx512m
-XX:MaxPermSize=256m
-XX:+UseConcMarkSweepGC
-XX:+CMSPermGenSweepingEnabled
-XX:+CMSClassUnloadingEnabled
-verbose:gc
-XX:+PrintGCDetails
-XX:+PrintGCTimeStamps
-Xloggc:E:/log/gc.log
-XX:+HeapDumpOnOutOfMemoryError
-Xss512k -- Stack size

-- Ubuntu
java -XX:+PrintFlagsFinal -version | grep -iE 'HeapSize|PermSize|ThreadStackSize'
java -XX:+PrintFlagsFinal -Xms512m -Xmx1024m -Xss512k -XX:PermSize=64m -XX:MaxPermSize=128m -version | grep -iE 'HeapSize|PermSize|ThreadStackSize'

--Windows
java -XX:+PrintFlagsFinal -version | findstr /i "HeapSize PermSize ThreadStackSize"
java -XX:+PrintFlagsFinal -Xms512m -Xmx1024m -Xss512k -XX:PermSize=64m -XX:MaxPermSize=128m -version | findstr /i "HeapSize|PermSize|ThreadStackSize"