BEA WebLogic VE brings virtualization to the application server
Our product review reveals that WebLogic Server Virtual Edition is a bold innovation that effectively leverages VMware server virtualization but is currently hampered by a lack of management tools
What’s it for?
The WebLogic Virtual Edition is not a performance play, even if that was part of the original inspiration. Benchmarks show that it appears exactly where you’d expect: in the narrow range between the slower virtualization with a full operating system and the faster native binaries running without virtualization. As virtualization performance has improved (due in good part to virtualization-specific optimizations in the processor), the differential between virtualized and native performance has continued to shrink. So, the small lift this product provides inside that narrow performance differential between the two platforms is not the main goal.
Rather, effective management is. The obvious management benefit is deployment and provisioning. No longer do you have to spend days loading up a Java app server and configuring it for the hardware it runs on. Now, the server comes preconfigured and ready to run. The second benefit is that as an appliance, VE can be moved around easily. It can be stopped and migrated to another system for maintenance on the underlying hardware, for system upgrades, and especially for load-balancing purposes. This last usage is the one contemplated by BEA. A site would have multiple instances running on different machines. These could be started up as needed, then migrated across hardware platforms as requirements, loads, and resources dictate.
To this end, the company is working on a release of its Liquid Operations Control (LOC) that enables visual management and administration of a VE instance as a mobile, deployable asset. Currently in beta, the LOC console will make it easy to manage many VE appliances at large sites.
A final management benefit occurs at the hardware level: The LiquidVM requires less memory than an OS-based VM implementation. The reason is that the JVM knows how much memory it needs. It also can release memory back to the system when it’s no longer needed. In comparison, operating systems run numerous extraneous services that consume RAM, and they frequently have to allocate large memory blocks (especially in the case of Windows) reserved in the event of a sudden spike in processing load. This reserved space remains mostly unused and unavailable to other applications. Because VE does not do this, more instances of the appliance can share a server, resulting in better use of the hardware.
Impressions from the lab
I examined a shipping version of VE and found it to be somewhat uneven. Installation was hampered by insufficient documentation, and I had to make use of the tech support staff at my disposal for simple provisioning — exactly the opposite of the expected experience. Ultimately, I got VE running satisfactorily. The server is in all key regards the native version you’d get from BEA, and the VE administration console looks like that of the regular WebLogic product. However, VE is currently stuck at release 9.2, whereas the flagship version of WebLogic for native systems is at release 10.3. VE does cost slightly less than its native version counterpart. Presumably the idea is to encourage adoption of multiple instances because of the management and operational benefits mentioned previously.