Zheng Tech Blog

Although there is a similar blog entry on this topic, I’d rather to blog it anyway for my own reference. If the WebLogic Server was installed on Linux and when starting, you might see the following message: What happened is the default JRockit JVM prefers to uses large pages for Java heap but the Linux OS is not setup yet for this option. HugePages is a feature integrated into the Linux kernel 2.6. It’s a method to have larger page size that is useful for working with large memory. HugePages is userful for both 32-bit and 64-bit configurations. Its size varies from 2MB to 256MB, depending on the kernel version and the hardware architecture. Using HugePages reduces the OS maintenance of page states, and increases Translation Lookaside Buffer (TLB) hit ratio. Run the following will show a filesystem of type hugetlbfs configured in the kernel: cat /proc/filesystems First, we need to create the hugepages director...

Performance for WebCenter/ADF is always a hot topic. For every application (ADF web apps, WebCenter Portal/Spaces apps, or others), you will be ended up to deal with it sooner or later. Sooner is of course better, it's recommended to be considered at the time the project is plotted out since you will need to consider your budget for hardware/software acquisitions. I have experienced with couples of clients that requested to tune performance after the application went to production which is still OK but not the ideal time, simple because there are so many restrictions dealing with performance tuning after it went on production. The performance no doubt is a broad topic. This article will try to include a checklist of areas you need to bear in mind for the matter of performance in the WebCenter/ADF world, but will not go into very detail on each section. Performance is limited by many factors, such as hardware resource and the application architecture. The CPU type/speed,...

A handy place to look at the JPA annotation reference: http://www.oracle.com/technetwork/middleware/ias/toplink-jpa-annotations-096251.html