From: "Chris Warr" <[EMAIL PROTECTED]> > > Hi, I'm a bit of a newbie so go easy on me if I get things wrong. > > We're also having trouble with with cocoon under load. We're running under > NT4 SP6a, Tomcat 4.0.3, Cocoon 2.0.2, and JDK 1.3.1. We've got a webapp > that connects to an MSSQL Server 2000 db using Microsoft's jdbc driver, it > reads some XML from the db then uses FOP to generate a PDF. The app works > fine under low load however once we beef it up to say 20 processes querying > concurrently bad things happen. Firstly we were using cocoon 2.0.1 as you > are and found after about 1500 hits cocoon would hang, as you found, Tomcat > was still okay, and even the sample webapps still run. So it's our webapp > only that hangs. THe last few days I've upgraded to Cocoon 2.0.2 and > haven't encountered the hang-up problem. However I have a new problem, > after a random amount of time (the furthest I've got is 2500 hits, the > quickest was 100 hits) the jvm crashes. I'm running Tomcat standalone in a > command prompt. The error comes in a message box, something about a > reference to a null pointer (0x000000), sorry I don't have the exact message > handy, trying to replicate but it takes a while to get to the problem > numbers. Anyone else seen this, would upgrading to Tomcat 4.0.4b2 or JVM > 1.4 help at all. To use 1.4 do I need to rebuild cocoon, or just run it all > with jvm 1.4?
I've had the same problems with many versions of Tomcat, Cocoon, and JDK. The problem is the Microsoft drivers and (in the case of Access) the JDBC-ODBC bridge driver. Never use the bridge in a production environment; we had crashes when simply closing connections! Also, Microsofts driver limits in some way the performance: http://www.eweek.com/article/0,3658,s=708&a=23115,00.asp " Out of all the drivers we used, Microsoft's new JDBC driver had the most problems. It's still a beta driver in the form distributed on Microsoft's Web site, but it's not a new product per se, because it's based on code licensed from DataDirect Technologies Inc., which has had the leading third-party SQL Server JDBC driver for some years now. Providing and supporting its own JDBC driver is a very welcome move, and Microsoft officials informed us last month that they had 70,000 downloads of the driver so far, so there is considerable customer interest in it. However, the driver, in both Beta 1 and Beta 2 forms (we tested both), has serious performance and stability problems. Using the driver, we were unable to get more than about 200-page-per-second throughput, and the problem was clearly the driver-the database was only at about 15 percent to 20 percent CPU utilization at this load. The driver also has memory leaks: We could see on WebLogic's administration console that less memory was freed each time the Java virtual machine did a garbage collection. Because of these leaks, the Microsoft JDBC driver was unable to run for 8 hours straight. " You should change driver (see 3rd party) od DB ;-) -- Nicola Ken Barozzi [EMAIL PROTECTED] - verba volant, scripta manent - (discussions get forgotten, just code remains) --------------------------------------------------------------------- --------------------------------------------------------------------- Please check that your question has not already been answered in the FAQ before posting. <http://xml.apache.org/cocoon/faqs.html> To unsubscribe, e-mail: <[EMAIL PROTECTED]> For additional commands, e-mail: <[EMAIL PROTECTED]>
