What parameters in an application server are most important to examine when monitoring for availability and optimal performance? Why are these parameters important? How do you tune them once you have collected measurements?
This is the second part of the question. The first part is what are you trying to do with the application server? The demands of an e-commerce site are drastically different from the demands of a publishing site that present information but doesn't receive any. And the demands of high-volume sites are totally different from those of low-volume sites.
Here are some general concerns with regard to availability and performance:1. Bandwidth and hardware up-time. Basics, not involved with application servers, but probably the most critical performance issues.
2. Security. In most cases, security degrades performance. Not just user log-in, but encryption, SSH, etc. all involve duplicate processing.
3. Memory. At least on Unix-based systems, seems to be more potent a performance indicator than raw processor power (and it's cheaper).
4. Synchronization (databases and application server instances). Distributed systems are generally more reliable, but there -is- a cost to network access.
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