AurÃlien DEHAY a dit::
Hello.
Le samedi 06 novembre 2004 Ã 10:09 -0500, Shilpa Kelkar a Ãcrit :
Hello
We have a website developed in cocoon 2.0 running on tomcat 5.0.27 on linux server.
We are using jvm 1.4.2.
Sun? Weblogic (Jrockit)? Intel architecture?
BEA's JVM is running only on Intel architecture (and only on Windows ansd Linux). The very interesting feature of JRockIt is the possibility to configure a auto-tune GC (JRockit is able to switch from, for example, a parallel GC to a concurent GC for best perfs).
With 1.4.2, there is mainly 3 GC:
- historical (like <1.4.2), it run on a single CPU and freeze all the running applications during garbage collection.
- parallel. It run on all the CPU of the server (benefits only when you have a multi CPU server of course), but still freeze the application
- Concurrent: runs concurently on a separate thread (idealy on a multi CPU server). Doesn't freeze the JVM
The choice of a GC is very difficult between the second and the third option (the first is rarely a good choice. Except on a single CPU server, on which the choice of the garbage collector is not really important). The concurrent GC seems to be a good idea, but what happens if you allocate more memory than the GC is able to free (here is the benefit of the jrockit: it make the choice for you, because the reality is much more complicated than that: parallel/concurrent mark, parralel/concurrent sweep, generational memory management or fixed single space.... The choice (and much more the tuning) of a GC is often a real headache)?
The website is few xml and xsls with 15 java code files. The database used is mysql.
The website is database extensive and does a lot of queries to generate the pages.
We can handle about 1000 concurrent users currently.
Hmmm... Concurrents users on a non connected protocol like http is quite hard to evaluate. What do you mean by concurrent?
Concurrent sessions in your webapp server? Mainly a problem of memory then. Are there sessions stored in a database? filesystem? Are the users really actives?
We need to scale the system almost 10 times the current.
The first question I should have asked is: is your database server able to handle 10 times more queries? It is often much simplier to multiplicate the number of servers (you can look at c-jdbc (on objectweb site) for mysql clustering. Haven't tried it, but look terrific)
Rgds.
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