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Showing posts from March, 2016

JVMMON help commands

Hello , jvmmon is an excellent tool for JBOSS administrators and please find below list of commands for jvmmon  Print commands: __________________________   print arenastat                             - Prints brief arena statistics   print arenastat full                        - Prints detailed arena statistics   print class statistic                       - Prints class statistics of a VM   print cluster memory information            - Prints information about the memory consumption of the cluster   print codeblobs                             - Prints information about code blobs with specified name   print debugging information                 - Prints information about the debugging state of a VM   print detailed class statistic              - Prints detailed class statistics of a VM   print dll info                              - Prints information about the loaded shared libraries of a VM   print flight recorder                       - Prints part of the flight rec

Python Object reference well explained with list

Assume you have a list and you want to make exact copy of the list. What command you will use in python to copy a list from another list. I used List1=List2 and List1 got copied as exactly as List2 but what happen internally is they have shared command object reference location. Dont believe ? then lets try and try to see both lists location with id function id() I mean do as  id(List1) and id(List2) , you will find command location for these two which means they are sharing common location and what ever operations you do they will reflect on both lists.And this is completely harmful and dangerous. So to avoid this list copying can be done in other methods where two list will have two different object locations. They are list2=copy.copy(list1) (or) list2=list1[:] (or) list2=list(list1) and for more information about object reference understanding in python I recommend you to read these http://stackoverflow.com/questions/36244451/how-to-program-python-variable-to-

How to get full application propery reports by using jvmmon ?

Hello , Let come straight to the point. If you want to see right now with what properties your Jboss application servers are running , Please type jvmmon and choose current PID of your JBOSS process. Then type print system properties It will flood your stdout , copy and paste it in a file and you can use to analyse. else you can save it to a file in your system. $ print to file file = /tmp/fromjvmmon $ print system properties -- printed to local file /tmp/fromjvmmon $ exit and to take thread dump use  jvmmon $ print to file file =/tmp/threaddump $print stacktrace it will autosave threaddump in the above location and similarly to take heap dump.  type jvmmon $dump heap it will dump heap automatically into location as mentioned in run.conf Thank you. Regards Raja