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Showing posts from July, 2010

Heap dump on a Unix machine

After exploring the Jay/Faisal's blog on 'jmap' java utility usage and Heap dump. It is really great work by Jay/Faisal. I just thought that similar kind of experiment we did long back on UNIX machines. I am glad to sharing that with you guys. Last year, we were struggling to overcome the OutOfMemoryError, which would effect the most of productive hours. In this assignment I need to figure out what process is causing the low memory in the environment is identified by searching a all log files in the machine. Assume that all the WebLogic instance log files are collected into common directory structure, each of them are stored respective instance named folder. Script 1: After identifying the impacted instances, I need to take the heap dump of that particular instance with corresponding process id. #============================================================== # File Name : CheckLogs.sh # Author : Pavan Devarakonda # Purpose : Script for searching all WebLogic in...

Clearing Cache for WebLogic instance

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Hey smart WLA,  Here I am with one more interesting story of WebLogic Administration "Clearing Cache". This is most often in development environments, where you need to clear the cache for new releases for Web-tier changes, XML loadings, JDBC connection changes, JMS issues, etc.,. Some of the great developers think like this "I can change minor things directly in the jsp files to test stuff" What is actually WebLogic Cache? Basically all the web-tier related files (.jsp .class, JSPCompiled files etc.,) get stored in ./wlnotdelete/app_yourapplicaiton directory. This is treated as cache whenever there is a restart of a WebLogic instance happen then the WebLogic server will look up for last serviced object status stored in the cache to service for any pending requests. Usually, when your EJB Classes need sessions, JMS object requires persistence, your web-tier may contain static contents then Cache will be used by WebLogic Application Server instance. Cache Cleari...

Copying to multiple remote machines

Here is another interesting story of WLA (of-course mine), When I visited US in 2007 there was lot of restrictions in work places. "Hey its production you know what happen if you touch it??" "Don't open this files", "Don't enter into that folders", it will be dangerous... I know that very well what is missing in the system, where it is required a change but my hands kept criss cross!! Days passed I got opportunity to come again on long term. Now, the whole new System is going shapeup with my hands. The system is awaiting for me since long days. :) All those sparkling colorful ideas running around my mind, got chance to flow onto the system to form various automated scripts, which are having little in size with greater capabilities. Whenever there is a application version release the archive files(.jar, .war, .ear) need to copied to all over the remote machines. In olden days we were using 'sftp' command and its related 'put', 'm...