> From: Joe Reger, Jr. [mailto:[EMAIL PROTECTED] > Subject: Re: How much memory will Tomcat 5.5/Java 5 support? > > How would you go about using more of the memory that I have on the > server? Can I run two Tomcat services and cluster?
32-bit Windows normally only provides 2 GB of virtual space per process. There is a boot-time option (I forget what it is) for some server versions of Windows to increase that to 3 GB. This is a tradeoff with system resources, since doing so reduces the amount of virtual space for the kernel to 1 GB. Windows loads several discontiguous DLLs within the virtual space of each process, so that fragments it somewhat, and the last time I checked, a HotSpot JVM required contiguous space for the heap. Also, there was a bug in the 1.4 32-bit JVM dealing with heap sizes larger than 2 GB due to sign extension problems, but that may be fixed now. (Haven't looked at the heap init code in 1.5.) 64-bit versions of Windows and the JVM obviously don't have these issues. Running multiple instances of Tomcat would certainly allow you to use more total memory, since each Tomcat process will get its own 2 GB. However, clustering doesn't come free - there's a good bit of overhead involved due to the instances sharing state. You'll have to test with your actual applications to see if the performance is acceptable. - Chuck THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus for use only by the intended recipient. If you received this in error, please contact the sender and delete the e-mail and its attachments from all computers. --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
