For the Xmx and Xms sizes being equal force the JVM memory space to be one static size. When specifying and lower minimum size your allowing the JVM to dynamically adjust it's memory space as needed from the min to the max. This has been problematic for the JVM in years and versions past. Setting them to be equal keeps the JVM static and stable.
Java has Generational garbage collections. Newer items that have terminated are cleaned up more often than older items that are still in use. As I said the Maxpermsize and permsize are for the perm gen memory sizes. Perm gen is where long lived java classes that are executed are stored (until they expire). By allowing a larger permsize your allowing more java classes (aka CF pages or CFC's) to be compiled once and stored. If your site is heavy on CFC's then increasing the setting to 256m may be option. Again the same reason for keeping the min and max the same applies. Also, these setting relate to garbage collecting (GC). You have Eden or 'New Gen' and 'Perm Gen' heaps. Eden is where new classes are stored and are cleaned out by GC more often than Perm Gen memory. Perm Gen is where longer persisting classes in the Eden are move to when it is determined the are longer lived than allowed in Eden. Perm Gen is Permanent meaning it has been determined these classes are used enough to be granted eternal life in memory (or until the perm gen memory space runs out. There is a lot of dry material out there if you want to really be a JVM tuning wizard. Also, much of the info is old and partially outdated. Plus, the info changes per JVM brand (JBOSS has different settings that Sun's). Myself and our sysadmin where I work have read much of this stuff and found the settings that work best for high availability cf servers via the time test trial and (much) error method. We're running mlsfinder.com which sees about 2.25 million page views per day. Most of what people are doing on the site are large searches for houses. Oh, and also add -server to your java.args line. This specifies to run the JVM in server mode. As opposed to client or hotspot modes. Wil Genovese One man with courage makes a majority. -Andrew Jackson A fine is a tax for doing wrong. A tax is a fine for doing well. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Adobe® ColdFusion® 8 software 8 is the most important and dramatic release to date Get the Free Trial http://ad.doubleclick.net/clk;192386516;25150098;k Archive: http://www.houseoffusion.com/groups/CF-Talk/message.cfm/messageid:307306 Subscription: http://www.houseoffusion.com/groups/CF-Talk/subscribe.cfm Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=89.70.4
