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Showing posts from January, 2011

Clearing Hazelcast data grid cache with Oracle Database change notification

UP1: if you are interested in in-memory computing, we recommended the book "High performance in-memory computing with Apache Ignite" . A few days ago we decided to use 2nd level cache for better java scalability in our legacy system. Everything goes fine with hazelcast as a 2nd level cache, whenever our a few 3rd party applications starts uploading data directly to the Oracle schema. Generally, a middle-tier data cache duplicates some data from the back-end database server. Its goal is to avoid redundant queries to the database. However, this is efficient only when the data rarely changes in the database. The data cache has to be updated or invalidated when the data changes in the database. If application operates DML operations through cache it's simply your life, but in our case some of our 3rd party can't use hazelcast data grid and we decided to get the proper way to update our caches or clear it whenever some entity on tables updates. In this post i will pr

J2EE application profiling with yourkit on Weblogic

One of our provider uses HP-UX on production machine, a few J2ee applications runs on that machine. After sometimes, we start getting complain from our clients that portal often goes out of memory and we decided to investigate the application with Yourkit . Yourkit is a industry leading java profiling software on present day, it can works with standalone java application as well as remote profiling. YourKit supports SQL,JNDI and run time memory profiling, see the following link for more information . 1) First download the version you need, in my cases i download Windows and HP-UX version and got the evaluation key. 2) Unzip the YJP-9.5.3*.zip and run the following command on HP-UX to set the agent for profiling on weblogic  cd yjp-9.5.3/lib & java -jar yjp.jar -integrate which will bring up you new command console to configure agent with the weblogic server. Go throws the command prompt and locate your weblogic startup script as follows: Now you will get a new startup scrip