Thanks. This server has 1.5GB of memory, so I can set the heap larger as needed. The funny thing is that tools keep showing plenty of memory available ( % of Free Allocated Memory: 80-98%), but the Full Garbage Collection happens so often it just seems wrong.
And the JVM allocates more memory where it's not needed (PSOldGen) and allocates less memory where it is needed (PSYoungGen). I'm going through a number of articles and blogs looking for info, and was hoping someone here could put their finger on the answer. The ( -XX:+PrintGCTimeStamps -XX:+PrintHeapAtGC -XX:+PrintGCDetails -Xms256m ) are indeed just for debugging. This is a test server and we're trying to tune it for the applications. We had some hangs and crashes on the Production server with OutOfMemory errors. many thanks, Chris ---------- Original Message ---------------------------------- From: "Robertson-Ravo, Neil (RX)" <[EMAIL PROTECTED]> Reply-To: [email protected] Date: Wed, 18 May 2005 13:50:45 +0100 >Well from what you state - it would seem the case that your app is using >more than you have allocated it hence purge via GC to clear the queue. > >What are your server specs? > >I would also remove XX:+PrintGCTimeStamps -XX:+PrintHeapAtGC >-XX:+PrintGCDetails -Xms256m. I know they are probably for debugging but >they will have a detrimental effect on performance. > > > > >-----Original Message----- >From: Chris Norloff [mailto:[EMAIL PROTECTED] >Sent: 18 May 2005 13:27 >To: CF-Talk >Subject: CFMX GC every 60 sec.? > >Is it right for Garbage Collection to run every 60 sec., as regular as >clockwork? > >(CFMX 6.1 server, with updater, Solaris 8. JVM settings: -server >-Dsun.io.useCanonCaches=false -XX:MaxPermSize=256m -XX:+UseParallelGC >-Djavax.xml.parsers.SAXParserFactory=com.macromedia.crimson.jaxp.SAXParserFa >ctoryImpl >-Djavax.xml.parsers.DocumentBuilderFactory=com.macromedia.crimson.jaxp.Docum >entBuilderFactoryImpl -XX:+PrintGCTimeStamps -XX:+PrintHeapAtGC >-XX:+PrintGCDetails -Xms256m -Xmx768m) > >I'm trying to decide if what I'm seeing is right: > >- first unloaded classes after running for 13 min. >- PSPermGen getting to 98% but not increasing size to what's available >(MaxPermSize=256m) >- 'from space' in PSYoungGen regularly filling, appears to be causing the >GC. >- GC runs every 60 sec. >- PSOldGen gets the most space of the heap, but 'from space' in PSYoungGen >is what *needs* the space. >- NOTE: this is with the server idle. Now I need to see it under load. > >thanks, >Chris Norloff > >---------------------------------------------- >Heap > PSYoungGen total 87168K, used 84000K [0xb9000000, 0xbe550000, >0xc9000000) > eden space 3008K, 0% used [0xb9000000,0xb9000000,0xb92f0000) > from space 84160K, 99% used [0xb92f0000,0xbe4f8000,0xbe520000) > to space 192K, 0% used [0xbe520000,0xbe520000,0xbe550000) > PSOldGen total 174784K, used 6449K [0xc9000000, 0xd3ab0000, >0xe9000000) > object space 174784K, 3% used [0xc9000000,0xc964c5a8,0xd3ab0000) > PSPermGen total 16640K, used 16453K [0xe9000000, 0xea040000, >0xf9000000) > object space 16640K, 98% used [0xe9000000,0xea011630,0xea040000) >15399.411: [Full GC 90449K->6460K(261952K), 0.6580179 secs] > Heap after GC invocations=510: >------------------------------------------------------------ >- just like clockwork. this is obviously the established pattern. > > PSYoungGen total 87232K, used 84136K [0xb9000000, 0xbe550000, >0xc9000000) > eden space 3008K, 0% used [0xb9000000,0xb9000000,0xb92f0000) > from space 84224K, 99% used [0xb92f0000,0xbe51a010,0xbe530000) > to space 128K, 0% used [0xbe530000,0xbe530000,0xbe550000) > PSOldGen total 174784K, used 6136K [0xc9000000, 0xd3ab0000, >0xe9000000) > object space 174784K, 3% used [0xc9000000,0xc95fe3a8,0xd3ab0000) > PSPermGen total 16640K, used 16465K [0xe9000000, 0xea040000, >0xf9000000) > object space 16640K, 98% used [0xe9000000,0xea014600,0xea040000) >64676.110: [Full GC 90272K->6157K(262016K), 0.6643557 secs] > Heap after GC invocations=2134: > >---------------------------------------------------------------- > PSYoungGen total 86976K, used 83817K [0xb9000000, 0xbe550000, >0xc9000000) > eden space 3008K, 0% used [0xb9000000,0xb9000000,0xb92f0000) > from space 83968K, 99% used [0xb92f0000,0xbe4ca6c8,0xbe4f0000) > to space 384K, 0% used [0xbe4f0000,0xbe4f0000,0xbe550000) > PSOldGen total 174784K, used 6955K [0xc9000000, 0xd3ab0000, >0xe9000000) > object space 174784K, 3% used [0xc9000000,0xc96caea8,0xd3ab0000) > PSPermGen total 17664K, used 17337K [0xe9000000, 0xea140000, >0xf9000000) > object space 17664K, 98% used [0xe9000000,0xea0ee670,0xea140000) >71170.151: [Full GC 90773K->7168K(261760K), 1.0508560 secs] > Heap after GC invocations=2348: > > > > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Discover CFTicket - The leading ColdFusion Help Desk and Trouble Ticket application http://www.houseoffusion.com/banners/view.cfm?bannerid=48 Message: http://www.houseoffusion.com/lists.cfm/link=i:4:207022 Archives: http://www.houseoffusion.com/cf_lists/threads.cfm/4 Subscription: http://www.houseoffusion.com/lists.cfm/link=s:4 Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=89.70.4 Donations & Support: http://www.houseoffusion.com/tiny.cfm/54
