Does 5.1 log garbage collection like 4.5.2?

The weblogic 4.5.2 release notes state that the server will log whenever it
garbage collects, see below. Does 5.1 do this?
"We changed the distributed garbage collection server to always indicate
that it is running by adding entries to the Server log file. A typical entry
is:
Thu Aug 19 19:44:28 PDT 1999: <DGCserver>
Freed 1086 objects in 30 ms, 24 exported object remain."

It should. There is a slight possibility that it might not appear as a
feature until service pack No. 4 if the change to version 4.5.2 was not done
until after service pack three was completed.
If you do not see it in service pack No. 4, please report to support.
Thanks,
Michael
Michael Girdley
Product Manager, WebLogic Server & Express
BEA Systems Inc
Mark Johnson <[email protected]> wrote in message
news:396bbb8f$[email protected]..
The weblogic 4.5.2 release notes state that the server will log wheneverit
garbage collects, see below. Does 5.1 do this?
"We changed the distributed garbage collection server to always indicate
that it is running by adding entries to the Server log file. A typicalentry
is:
Thu Aug 19 19:44:28 PDT 1999: <DGCserver>
Freed 1086 objects in 30 ms, 24 exported object remain."

Similar Messages

Garbage Collection is not destruction?

Garbage Collection is not destruction?
This is one of the point from Thinking In Java 4th edition Chapter 5.Can someone please explain me this point.Does that mean that Garbage Collection does not destroy objects.If yes,then what is it role?
And also please explain something about finalize().I tried to read it but couldn't understand.
Thanks for your help.

personal opinion really. I do call garbage collection destruction, the memory occupied by the objects in question is reclaimed. It is a discussion point however as it is from the perspective of the JVM; from the perspective of the application the object is "destroyed" as soon as you cut all references to it.
What to explain about finalize()? It is invoked right before an object is garbage collected, possibly allowing you to do some last minute clean up jobs, like letting go of resource handles and such. The general rule about it is that in 99.99% of the cases you need not touch it. If you have a design where you need it, it is best to assume the design is wrong and you need to change it. For example in the case of closing resources, it is better to have a close() method that needs to be invoked manually.
If you do use it, you better be really sure that you know what you are doing as you may cause performance problems or even hard to trace unexpected behavior.

Swing & Garbage Collection

If the EventQueue is very active does that starve the garbage collection? Here is the scenario:
Lets say I have a JFrame that listens for a specific keyboard event. In processing that event a heavy weight JComponent is created and displayed within that frame. If the user, in rapid succession, triggers those key events, and continues to, the allocated memory increases dramatically unitl an out of memory exception occurs.
Does anyone know if alot of processing is occuring on the Swing EventQueue if that might starve garbage collection?
Thanks
Scott

Firstly, if garbage collection is happening later then you're probably ok. You can't force garbage collection - as long as it gets cleared later the only problem you should ever have is the possibility of some piece of code being slowed slightly by the garbage collector kicking in.
Secondly, it's best to flush() images before the references are lost. Note that you lose an image reference during your getScaledInstance() line, so you should use a temporary variable to allow you to flush.
It's been a long time since I looked at Jimi, might you need to perform some sort of cleanup on that canvas before nulling it? I'm also not sure why you're using File and JimiCanvas objects when you can just use the ImageIcon(String) constructor to load the image in one line and reduce the risk of introducing errors.

Looking for the Garbage Collection log files

Hello,
I am looking for the Garbage Collection log files which contain the GC events, like this:
[GC 2095K->1709K(2160K), 0.0017628 secs]
[Full GC 2161K->1018K(2276K), 0.0576353 secs]
The server's GC is already configured accordingly:
verbose:gc
I have examined the std_server<x>.out files at the work folder but can't see this info.
My question is: Where would I find these files on the server?

I can't find info in the format I know it not at dev_server* or std_server*.
in std_server I see xml file like this:
<gc type="scavenger" id="1" totalid="1" intervalms="0.000">
 <flipped objectcount="303111" bytes="24994248" />
 <tenured objectcount="0" bytes="0" />
 <refs_cleared soft="429" weak="4329" phantom="0" />
 <finalization objectsqueued="1711" />
 <scavenger tiltratio="50" />
 <nursery freebytes="497866672" totalbytes="524288000" percent="94" tenureage="10" />
 <tenured freebytes="1094921936" totalbytes="1098907648" percent="99" >
 <soa freebytes="1039977168" totalbytes="1043962880" percent="99" />
 <loa freebytes="54944768" totalbytes="54944768" percent="100" />
 </tenured>
 <time totalms="185.585" />
</gc>
I guess this is the info I need but it's not formatted in a way that your tool can read it and having a tool like this reading it is very helpful.
Any ideas?

Garbage collection logs

In the following garbage collection logs:-
84818.180: [GC 84818.180: [ParNew: 159810K->11632K(172032K), 0.0475511 secs] 520283K->372704K(1024000K), 0.0477481 secs]
84874.024: [GC 84874.024: [ParNew: 159088K->14118K(172032K), 0.0552993 secs] 520160K->375190K(1024000K), 0.0554933 secs]how would you find out when the garbage collection cycle actually took place? i.e. absolute time

In the following garbage collection logs:-
84818.180: [GC 84818.180: [ParNew:
159810K->11632K(172032K), 0.0475511 secs]
520283K->372704K(1024000K), 0.0477481 secs]
84874.024: [GC 84874.024: [ParNew:
159088K->14118K(172032K), 0.0552993 secs]
520160K->375190K(1024000K), 0.0554933 secs]how would you find out when the garbage collection
cycle actually took place? i.e. absolute timeI normally try to update my posts in case somebody in future comes across the same question, he finds an answer to the problem as well and not just the problem. So what I found out was that in the above gc logs, 84818.180 would be the no. of seconds since the start of the appserver, and one would have to get that time from stderr.log file. So once you get that time from stderr log you need to add these sec to that time to get the absolute time. Its kind PIA but thats how it is, I am still not sure why they used this convention since time from start of the server would not mean anything for a developer analyzing the log files

When does garbage collection occur?

Answer the question!
thanks

Sometime after a objects become unreachable and before the memory allocator runs out of memory, the garbage collector will run. You have no way of controlling or knowing when that will be. There is no reason to.
For some reason, even though many programming languages have garbage collection, people seem to regard Java's garbage collection as something they need to "understand" and control. Garbage collection is best left up to the garbage collector -- that's its job, and just let it work.

Hotspot core dumping during JVM garbage collection ?

We have an application which calls a 3rd party supplied server API which has recently been upgraded to use Java 1.5
We are getting the following error reported by our client application. The application is also now running Java 1.5 but references many classes in jar files which would have quite old code in.
The supplier of the API has stated that the problem requires us to recompile all our jar files using v 1.5 ( including things like jconnect and jms ?!?!? ). This sounds like a bit of a cop-out to me, not to mention being impossible since we don't have the source for things like jconnect.
I suspect that there is a garbage collection problem at the bottom of all this, but I'm not sure how I can "prove" this, nor do I currently have any real clue as to how to fix any GC problem that may exist.
The application is supposed to wait for a message on a MQSeries queue and then transforms it via Xalan XSLT and sends it to a Server application. I've tried playing around with heap sizes etc but that just seems to make it worse. If I leave it at the settings that the previous version used then the client at least manages to process a couple of messages before core dumping. There doesn't seem to be a consistent trigger event to cause the core dump ( it's not a message arriving on a queue for example ) but it does seem to be fairly consistent timewise, i.e. after
Any ideas gratefully accepted.
Here's a logfile excerpt from my applications showing the Hotspot error message :
=====================================================================================
08-Jul-2008 10:01:05 Waiting for messages from COLT.BBFS
08-Jul-2008 10:02:05 Waiting for messages from COLT.BBFS
08-Jul-2008 10:03:05 Waiting for messages from COLT.BBFS
405.815: [GC [PSYoungGen: 17331K->9244K(37632K)] 111702K->103615K(192128K), 0.1615910 secs]
405.977: [Full GC#
# An unexpected error has been detected by HotSpot Virtual Machine:
# SIGBUS (0xa) at pc=0xfe141348, pid=2600, tid=8
# Java VM: Java HotSpot(TM) Server VM (1.5.0_03-b07 mixed mode)
# Problematic frame:
# V [libjvm.so+0x141348]
# An error report file with more information is saved as hs_err_pid2600.log
# If you would like to submit a bug report, please visit:
# http://java.sun.com/webapps/bugreport/crash.jsp
=====================================================================================
The logfile referred to in the error message contains the following.
=====================================================================================
# An unexpected error has been detected by HotSpot Virtual Machine:
# SIGBUS (0xa) at pc=0xfe141348, pid=2600, tid=8
# Java VM: Java HotSpot(TM) Server VM (1.5.0_03-b07 mixed mode)
# Problematic frame:
# V [libjvm.so+0x141348]
--------------- T H R E A D ---------------
Current thread (0x001484d8): VMThread [id=8]
siginfo:si_signo=10, si_errno=0, si_code=1, si_addr=0x0000080f
Registers:
O0=0x00487588 O1=0xfe7d6454 O2=0x000079b0 O3=0x00007800
O4=0x00008868 O5=0x00147d48 O6=0xf8781460 O7=0xfe0f7938
G1=0xe52aaae8 G2=0x00000003 G3=0x00000003 G4=0x001484d8
G5=0xf8781d98 G6=0x00000002 G7=0xf8781d98 Y=0x805683e2
PC=0xfe141348 nPC=0xfe14134c
Top of Stack: (sp=0xf8781460)
0xf8781460: fe786000 00c6ba20 fe10013c e54bab68
0xf8781470: 0000080f e54bab6c 0000080f 00000004
0xf8781480: 00487588 00000134 e54bab6c 00000004
0xf8781490: 00000001 00000000 f87814c0 fe17aef4
0xf87814a0: fe6485b4 fe7d899c 001484d8 0011da40
0xf87814b0: 00148988 00148c10 00148d7c f8781880
0xf87814c0: 007c3389 007c3c0e 00000f87 00008868
0xf87814d0: 00008800 00487588 fe141310 fe7d6454
Instructions: (pc=0xfe141348)
0xfe141338: ec 06 c0 1a 80 a5 a0 00 22 40 00 0a ba 07 60 01
0xfe141348: f2 05 a0 00 ae 0e 60 03 80 a5 e0 03 22 40 00 05
Stack: [0xf8702000,0xf8781d98), sp=0xf8781460, free space=509k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.so+0x141348]
V [libjvm.so+0x17aefc]
V [libjvm.so+0x2d557c]
V [libjvm.so+0x300ef8]
V [libjvm.so+0x301e84]
V [libjvm.so+0x2ff950]
V [libjvm.so+0x29df30]
V [libjvm.so+0x362b44]
V [libjvm.so+0x6436f0]
VM_Operation (0xe03012b0): parallel gc system gc, mode: safepoint, requested by thread 0x0031bca0
--------------- P R O C E S S ---------------
Java Threads: ( => current thread )
0x00b2c028 JavaThread "Thread-4" [_thread_in_native, id=85]
0x007f5048 JavaThread "Thread-0" [_thread_blocked, id=84]
0x00c27cf0 JavaThread "Notification Delivery" [_thread_blocked, id=81]
0x0026fa08 JavaThread "RMI LeaseChecker" daemon [_thread_blocked, id=73]
0x00821048 JavaThread "RMI RenewClean-[162.11.2.32:44425]" daemon [_thread_blocked, id=70]
0x0031bca0 JavaThread "GC Daemon" daemon [_thread_blocked, id=67]
0x00cd5d28 JavaThread "RMI Reaper" [_thread_blocked, id=66]
0x003c9300 JavaThread "Timer-0" daemon [_thread_blocked, id=65]
0x00929fe0 JavaThread "RMI TCP Accept-0" daemon [_thread_in_native, id=64]
0x0089bf18 JavaThread "SeedGenerator Thread" daemon [_thread_blocked, id=42]
0x00c47248 JavaThread "Pool thread #7" daemon [_thread_blocked, id=38]
0x00c466a0 JavaThread "Pool thread #6" daemon [_thread_blocked, id=37]
0x00311850 JavaThread "Pool thread #5" daemon [_thread_blocked, id=36]
0x00287a40 JavaThread "Pool thread #4" daemon [_thread_blocked, id=35]
0x00286e98 JavaThread "Pool thread #3" daemon [_thread_blocked, id=34]
0x00c134b0 JavaThread "Pool thread #2" daemon [_thread_blocked, id=33]
0x00ad09e0 JavaThread "Pool thread #1" daemon [_thread_blocked, id=32]
0x00286cd8 JavaThread "PoolThreadManager" daemon [_thread_blocked, id=31]
0x00c129e0 JavaThread "Channel Reaper" daemon [_thread_blocked, id=30]
0x00c669e8 JavaThread "ORB Daemon Thread" daemon [_thread_blocked, id=29]
0x00b10170 JavaThread "Worker for ServerProtocol: (iiop) /0.0.0.0:20168" daemon [_thread_blocked, id=22]
0x008a17e0 JavaThread "Syn~ Client" daemon [_thread_blocked, id=21]
0x003dc378 JavaThread "PoolScavenger0" daemon [_thread_blocked, id=20]
0x0015a928 JavaThread "Low Memory Detector" daemon [_thread_blocked, id=15]
0x00159880 JavaThread "CompilerThread1" daemon [_thread_blocked, id=14]
0x00158a18 JavaThread "CompilerThread0" daemon [_thread_blocked, id=13]
0x00157b98 JavaThread "AdapterThread" daemon [_thread_blocked, id=12]
0x00156dc8 JavaThread "Signal Dispatcher" daemon [_thread_blocked, id=11]
0x0014ccd8 JavaThread "Finalizer" daemon [_thread_blocked, id=10]
0x0014ad90 JavaThread "Reference Handler" daemon [_thread_blocked, id=9]
0x00038238 JavaThread "main" [_thread_in_native, id=1]
Other Threads:
=>0x001484d8 VMThread [id=8]
0x0015c3b0 WatcherThread [id=16]
VM state:at safepoint (normal execution)
VM Mutex/Monitor currently owned by a thread: ([mutex/lock_event])
[0x00037728/0x00037758] Threads_lock - owner thread: 0x001484d8
[0x00033650/0x00037ba8] Heap_lock - owner thread: 0x0031bca0
Heap
PSYoungGen total 37632K, used 9244K [0xf2eb0000, 0xf7ba0000, 0xf8400000)
eden space 28352K, 0% used [0xf2eb0000,0xf2eb0000,0xf4a60000)
from space 9280K, 99% used [0xf4a60000,0xf5367080,0xf5370000)
to space 25216K, 0% used [0xf6300000,0xf6300000,0xf7ba0000)
PSOldGen total 154496K, used 94371K [0xe8400000, 0xf1ae0000, 0xf2eb0000)
object space 154496K, 61% used [0xe8400000,0xee028e78,0xf1ae0000)
PSPermGen total 35584K, used 18260K [0xe4400000, 0xe66c0000, 0xe8400000)
object space 35584K, 51% used [0xe4400000,0xe55d5158,0xe66c0000)
Dynamic libraries:
0x00010000      /dsdvlp/java/jvm/jdk1.5.0_03/bin/java
0xff350000      /usr/lib/libthread.so.1
0xff340000      /usr/lib/libdl.so.1
0xff200000      /usr/lib/libc.so.1
0xff390000      /usr/platform/SUNW,Sun-Fire-880/lib/libc_psr.so.1
0xfe000000      /dsdvlp/java/jvm/jdk1.5.0_03/jre/lib/sparc/server/libjvm.so
0xff1e0000      /usr/lib/libsocket.so.1
0xff2d0000      /usr/lib/libsched.so.1
0xff1b0000      /usr/lib/libCrun.so.1
0xff160000      /usr/lib/libm.so.1
0xff080000      /usr/lib/libnsl.so.1
0xff060000      /usr/lib/libmp.so.2
0xff030000      /dsdvlp/java/jvm/jdk1.5.0_03/jre/lib/sparc/native_threads/libhpi.so
0xfdfc0000      /dsdvlp/java/jvm/jdk1.5.0_03/jre/lib/sparc/libverify.so
0xfdf80000      /dsdvlp/java/jvm/jdk1.5.0_03/jre/lib/sparc/libjava.so
0xfdf50000      /dsdvlp/java/jvm/jdk1.5.0_03/jre/lib/sparc/libzip.so
0xfb7e0000      /usr/lib/locale/en_GB.ISO8859-1/en_GB.ISO8859-1.so.2
0xe4190000      /dsdvlp/java/jvm/jdk1.5.0_03/jre/lib/sparc/libnet.so
0xe3bd0000      /dsdvlp/lib/5/libSolarisNatives.so
0xe3e90000      /dsdvlp/java/jvm/jdk1.5.0_03/jre/lib/sparc/librmi.so
VM Arguments:
jvm_args: -Djava.ext.dirs=/dsdvlp/java/tmijar/firs7/lib/cli:/dsdvlp/java/tmijar/firs7/lib/cli/ext:/dsdvlp/java/tmijar/firs7/lib/cmn/OpenORB:/dsdvlp/java/tmijar/firs7/lib/cmn/OpenORB/ext:/dsdvlp/java/tmijar/firs7/lib/cmn:/dsdvlp/java/tmijar/firs7/lib/cmn/ext:/dsdvlp/java/tmijar/firs7/daemonlib -Duser.dir=/dsdvlp/java/tmijar/firs7 -Dopenorb.config=file:/dsdvlp/java/tmijar/firs7/configs/OpenORB/config/SynOpenORB.xml -Dopenorb.home=file:/dsdvlp/java/tmijar/firs7/configs/OpenORB -Dcom.coexis.syn.general.orbbinding=com.coexis.syn.general.orbbinding.openorb.OpenORBBinding_1_4 -Dsun.rmi.dgc.client.gcInterval=360000 -Dsun.rmi.dgc.server.gcInterval=360000000 -Xms32m -Xmx256m -Dcom.coexis.syn.clientcommandsconfiglocation=file://localhost//dsdvlp/java/tmijar/firs7/configs/clientcommands.xml -Dcom.coexis.syn.clientconfiglocation=file://localhost//dsdvlp/java/tmijar/firs7/configs/fsbbtd_client.xml -XX:+PrintGCTimeStamps -XX:+PrintGCDetails
java_command: com.coexis.syn.mqmessaging.daemon.RunDaemon -p /dsdvlp/bin/5/lndsfsd_fsbbtd.properties start
Environment Variables:
JAVA_HOME=/dsdvlp/java/jvm/jdk150
CLASSPATH=.:/dsdvlp/java/jar/jconnect520.jar:/dsdvlp/java/jar/vbjapp340.jar:/dsdvlp/java/jar/vbjorb340.jar:/dsdvlp/java/jar/javax_jndi120.jar
PATH=/usr/local/etc:/usr/lang:/usr/openwin/bin:/usr/ucb:/bin:/usr/etc:/usr/local/5/bin:/dsdvlp/bin/5:/dsdvlp/bin/4:/home/app/sybase/5/bin:/home/app/sybase/5/localscripts:/home/app/sybase/5/sqr:/home/app/lang:/home/app/lang/SC2.0.1:/usr/ccs/bin:/usr/local/opt/Acrobat3/bin:/dsdvlp/bin:.
LD_LIBRARY_PATH=/dsdvlp/java/jvm/jdk1.5.0_03/jre/lib/sparc/server:/dsdvlp/java/jvm/jdk1.5.0_03/jre/lib/sparc:/dsdvlp/java/jvm/jdk1.5.0_03/jre/../lib/sparc:/usr/lib:/usr/openwin/lib:/usr/local/5/lib:/dsdvlp/lib/5:/dstest/lib/5:/home/app/sybase/5/lib:/dstest/cats/sun4/lib:/tmitest/Opus/opus/lib
SHELL=/bin/csh
DISPLAY=CLI00184.mfil.local:1.0
OS=5
--------------- S Y S T E M ---------------
OS: Solaris 8 2/02 s28s_u7wos_08a SPARC
Copyright 2002 Sun Microsystems, Inc. All Rights Reserved.
Assembled 18 December 2001
uname:SunOS 5.8 Generic_117350-20 sun4u (T1 libthread)
rlimit: STACK 8192k, CORE 9216k, NOFILE 4096, AS infinity
load average:2.24 2.67 2.68
CPU:total 4 has_v8, has_v9, has_vis1, has_vis2, is_ultra3
Memory: 8k page, physical 8388608k(166384k free)
vm_info: Java HotSpot(TM) Server VM (1.5.0_03-b07) for solaris-sparc, built on Apr 13 2005 03:31:26 by unknown with unknown Workshop:0x550

The very first suggestion I have is to move your VM to a more recent update of 1.5.0.
It looks like you are crashing with 5.0u3, and I'm pretty sure 5.0u16 is available. You
don't want to waste your time chasing a bug that's already been fixed.

High cpu usage for garbage collection (uptime vs total gc time)

Hi Team,
We have a very high cpu usage issue in the production.
When we restart the server, the cpu idle time would be around 95% and it comes down as days goes by. Today idle cpu is 30% and it is just 6th day after the server restart.
Environemnt details:
Jrockit version:
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2_05-b04)
BEA WebLogic JRockit(TM) 1.4.2_05 JVM R24.4.0-1 (build ari-38120-20041118-1131-linux-ia32, Native Threads, GC strategy: parallel)
Gc Algorithm: JRockit Garbage Collection System currently running strategy: Single generational, parallel mark, parallel sweep
Number Of Processors: 4
Max Heap Size: 1073741824
Total Garbage Collection Time: 21:43:56.5
Uptime: 114:33:4.1
Total Garbage Collection Count: 420872
Total Number Of Threads: 198
Number Of Daemon Threads: 191
Can you guys please tell me what would be problem in the server which causing the high cpu usage?
One more thing I would like to know is that why the total number of threads is 198 when we specified the Executor pool size as 25? I agree that weblogic would create some threads for its maintenance but around 160 threads!!! something is wrong I guess.
Santhosh.
[email protected]

Hi,
I'm having a similar problem, but haven't been able to resolve it yet. Troubleshooting is made even harder by the fact that this is only happening on our production server, and I've been unable to reproduce it in the lab.
I'll post whatever findings I have and hopefully we'll be able to find a solution with the help of BEA engineers.
In my case, I have a stand-alone Tomcat server that runs fine for about 1-2 days, and then the JVM suddenly starts using more CPU, and as a result, the server load shoots up (normal CPU utilization is ~5% but eventually goes up to ~95%; load goes from 0.1 to 4+).
What I have found so far is that this corresponds to increased GC activity.
Let me list my environment specs before I proceed, though:
CPU: Dual Xeon 3.06GHz
RAM: 2GB
OS: RHEL4.4 (2.6.9-42.0.2.ELsmp)
JVM build 1.5.0_03-b07 (BEA JRockit(R) (build dra-45238-20050523-2008-linux-ia32, R25.2.0-28))
Tomcat version 5.5.12
JAVA_OPTS="-Xms768m -Xmx768m -XXtlasize16k -XXlargeobjectlimit16k -Xverbose:memory,cpuinfo -Xverboselog:/var/log/tomcat5/jvm.log -Xverbosetimestamp"
Here are excerpts from my verbose log (I'm getting some HT warning, not sure if that's a problem):
[Fri Oct 20 15:54:18 2006][22855][cpuinfo] Detected SMP with 2 CPUs that support HT.
[Fri Oct 20 15:54:18 2006][22855][cpuinfo] Trying to determine if HT is enabled.
[Fri Oct 20 15:54:18 2006][22855][cpuinfo] Trying to read from /dev/cpu/0/cpuid
[Fri Oct 20 15:54:18 2006][22855][cpuinfo] Warning: Failed to read from /dev/cpu/0/cpuid
[Fri Oct 20 15:54:18 2006][22855][cpuinfo] Trying to read from /dev/cpu/1/cpuid
[Fri Oct 20 15:54:18 2006][22855][cpuinfo] Warning: Failed to read from /dev/cpu/1/cpuid
[Fri Oct 20 15:54:18 2006][22855][cpuinfo] HT is: supported by the CPU, not enabled by the OS, enabled in JRockit.
[Fri Oct 20 15:54:18 2006][22855][cpuinfo] Warning: HT enabled even though OS does not seem to support it.
[Fri Oct 20 15:54:55 2006][22855][memory ] GC strategy: System optimized over throughput (initial strategy singleparpar)
[Fri Oct 20 15:54:55 2006][22855][memory ] heap size: 786432K, maximal heap size: 786432K
[Fri Oct 20 16:07:30 2006][22855][memory ] Changing GC strategy to generational, parallel mark and parallel sweep
[Fri Oct 20 16:07:30 2006][22855][memory ] 791.642-791.874: GC 786432K->266892K (786432K), 232.000 ms
[Fri Oct 20 16:08:02 2006][22855][memory ] 824.122: nursery GC 291998K->274164K (786432K), 175.873 ms
[Fri Oct 20 16:09:51 2006][22855][memory ] 932.526: nursery GC 299321K->281775K (786432K), 110.879 ms
[Fri Oct 20 16:10:24 2006][22855][memory ] 965.844: nursery GC 308151K->292222K (786432K), 174.609 ms
[Fri Oct 20 16:11:54 2006][22855][memory ] 1056.368: nursery GC 314718K->300068K (786432K), 66.032 ms
[Sat Oct 21 23:21:09 2006][22855][memory ] 113210.427: nursery GC 734274K->676137K (786432K), 188.985 ms
[Sat Oct 21 23:30:41 2006][22855][memory ] 113783.140: nursery GC 766601K->708592K (786432K), 96.007 ms
[Sat Oct 21 23:36:15 2006][22855][memory ] 114116.332-114116.576: GC 756832K->86835K (786432K), 243.333 ms
[Sat Oct 21 23:48:20 2006][22855][memory ] 114841.653: nursery GC 182299K->122396K (786432K), 175.252 ms
[Sat Oct 21 23:48:52 2006][22855][memory ] 114873.851: nursery GC 195060K->130483K (786432K), 142.122 ms
[Sun Oct 22 00:01:31 2006][22855][memory ] 115632.706: nursery GC 224096K->166618K (786432K), 327.264 ms
[Sun Oct 22 00:16:37 2006][22855][memory ] 116539.368: nursery GC 246564K->186328K (786432K), 173.888 ms
[Sun Oct 22 00:26:21 2006][22855][memory ] 117122.577: nursery GC 279056K->221543K (786432K), 170.367 ms
[Sun Oct 22 00:26:21 2006][22855][memory ] 117123.041: nursery GC 290439K->225833K (786432K), 69.170 ms
[Sun Oct 22 00:29:10 2006][22855][memory ] 117291.795: nursery GC 298947K->238083K (786432K), 207.200 ms
[Sun Oct 22 00:39:05 2006][22855][memory ] 117886.478: nursery GC 326956K->263441K (786432K), 87.009 ms
[Sun Oct 22 00:55:22 2006][22855][memory ] 118863.947: nursery GC 357229K->298971K (786432K), 246.643 ms
[Sun Oct 22 01:08:17 2006][22855][memory ] 119638.750: nursery GC 381744K->322332K (786432K), 147.996 ms
[Sun Oct 22 01:11:22 2006][22855][memory ] 119824.249: nursery GC 398678K->336478K (786432K), 93.046 ms
[Sun Oct 22 01:21:35 2006][22855][memory ] 120436.740: nursery GC 409150K->345186K (786432K), 81.304 ms
[Sun Oct 22 01:21:38 2006][22855][memory ] 120439.582: nursery GC 409986K->345832K (786432K), 153.534 ms
[Sun Oct 22 01:21:42 2006][22855][memory ] 120443.544: nursery GC 410632K->346473K (786432K), 121.371 ms
[Sun Oct 22 01:21:44 2006][22855][memory ] 120445.508: nursery GC 411273K->347591K (786432K), 60.688 ms
[Sun Oct 22 01:21:44 2006][22855][memory ] 120445.623: nursery GC 412391K->347785K (786432K), 68.935 ms
[Sun Oct 22 01:21:45 2006][22855][memory ] 120446.576: nursery GC 412585K->348897K (786432K), 152.333 ms
[Sun Oct 22 01:21:45 2006][22855][memory ] 120446.783: nursery GC 413697K->349080K (786432K), 70.456 ms
[Sun Oct 22 01:34:16 2006][22855][memory ] 121197.612: nursery GC 437378K->383392K (786432K), 165.771 ms
[Sun Oct 22 01:37:37 2006][22855][memory ] 121398.496: nursery GC 469709K->409076K (786432K), 78.257 ms
[Sun Oct 22 01:37:37 2006][22855][memory ] 121398.730: nursery GC 502490K->437713K (786432K), 65.747 ms
[Sun Oct 22 01:44:03 2006][22855][memory ] 121785.259: nursery GC 536605K->478156K (786432K), 132.293 ms
[Sun Oct 22 01:44:04 2006][22855][memory ] 121785.603: nursery GC 568408K->503635K (786432K), 71.751 ms
[Sun Oct 22 01:50:39 2006][22855][memory ] 122180.985: nursery GC 591332K->530811K (786432K), 131.831 ms
[Sun Oct 22 02:13:52 2006][22855][memory ] 123573.719: nursery GC 655566K->595257K (786432K), 117.311 ms
[Sun Oct 22 02:36:04 2006][22855][memory ] 124905.507: nursery GC 688896K->632129K (786432K), 346.990 ms
[Sun Oct 22 02:50:24 2006][22855][memory ] 125765.715-125765.904: GC 786032K->143954K (786432K), 189.000 ms
[Sun Oct 22 02:50:26 2006][22855][memory ] 125767.535-125767.761: GC 723232K->70948K (786432K), 225.000 ms
vvvvv
[Sun Oct 22 02:50:27 2006][22855][memory ] 125768.751-125768.817: GC 712032K->71390K (786432K), 64.919 ms
[Sun Oct 22 02:50:28 2006][22855][memory ] 125769.516-125769.698: GC 711632K->61175K (786432K), 182.000 ms
[Sun Oct 22 02:50:29 2006][22855][memory ] 125770.753-125770.880: GC 709632K->81558K (786432K), 126.000 ms
[Sun Oct 22 02:50:30 2006][22855][memory ] 125771.699-125771.878: GC 708432K->61368K (786432K), 179.000 ms
So, I'm running with the default GC strategy which lets the GC pick the most suitable approach (single space or generational). It seems to switch to generational almost immediately and runs well - most GC runs are in the nursery, and only once in a while it goes through the older space.
Now, if you look at [Sun Oct 22 02:50:27 2006], that's when everything changes. GC starts running every second (later on it's running 3 times a second) doing huge sweeps. It never goes through the nursery again, although the strategy is still generational.
It's all downhill from this point on, and it's a matter of hours (maybe a day) before we restart the server.
I guess my only question is: What would cause such GC behavior?
I would appreciate your ideas/comments!
Thanks,
Tenyo

Garbage collecting threads

I am doing the following:
public class MyClass {
 private Thread t = null;
 public class testThread extends Thread{
 public void run(){
 String logName = this.getClass().getName();
 Logger.Print( logName ); // Basically prints logName to file
 for( int i = 1; i<4; i++){
 try{
 Thread.sleep(100)
 [do stuff]
 Thread.sleep(100);
 catch(InterruptedException e) { }
 public callThread(){
 if ( t != null ){
 if( !(t.isAlive()){
 t = new TestThread();
 t.start();
 else{
 t = new TestThread();
 t.start();
} What, I want to happen is a thread to finish and after that a new one to start, and once the old thread does not have any variable assoiciated to it anymore, it should get garbage collected as far as my java understnading goes, this is exactly what should happen, in duo time whenever the garabage collecter decides so. This is a very long time running program.
And the log shows the names of the threads like Thread-1 , Thread-2, Thread-3 , Thread-4, basically this name is increased by one everytime the function callThread is called and the old thread finished running, is there a limit to how many times I can call it like if it is called 10 billion times, will I have Thread-10000000000 in my log? and will the garbage collection work as I think? I am a c++ programmer so I do not trust it 100%, I really feel like adding delete t; so I can feel confident it is really gone before I do a t = new TestThread(); hehe C++ sickness??
Please give me advice on this!!! and I will be very happy!
Edited by: dakiar on Mar 19, 2008 8:18 AM

dakiar wrote:
What, I want to happen is a thread to finish and after that a new one to start,Use join(), rather than looping and checking isAlive, in order to determine when a thread has died.
while (true) {
Runnable r = new MyRunnable(); // You have no reason to extend Thread. It's preferable to implement runnable.
Thread t = new Thread(r);
t.start();
t.join();
and once the old thread does not have any variable assoiciated to it anymore, it should get garbage collected as far as my java understnading goes,It will become eligible for GC. There's no guarantee when or even if it will actually be GCed, other than that GC will at least happen before OutOfMemoryError.
And the log shows the names of the threads like Thread-1 , Thread-2, Thread-3 , Thread-4, basically this name is increased by one everytime the function callThread is called and the old thread finished running, is there a limit to how many times I can call it No.
like if it is called 10 billion times, will I have Thread-10000000000 in my log? Perahps. Or if Thread uses an int then it might wrap around to Integer.MIN_VALUE and give Thread--2147483648.
You know you can assign your own names to the Threads.
and will the garbage collection work as I think? It will work fine, and that has nothing to do with thread names.
I am a c++ programmer so I do not trust it 100%,So, you think that you managing memory ad-hoc in every program you write when you're trying to focus on implementing the business requirements of your app will be better at it than the guys who were specifically focussed on writing memory management that would be handled consisently by the computer, and has been continuously refined, not to mention tested by thousands of Java developers over the last dozen or so years?
I really feel like adding delete t; You can't and you don't need to.

Why Garbage Collection take more time on JRockit?

My company use 
BEA WebLogic 8.1.2 
JRockit version 1.4.2 
Window 2003 32bit 
RAM 4 Gig 
 
-Xms = 1300 
-Xmx = 1300 
and running ejb application. 
My problem is why JRockit take more time. How Can I solve this problem. Because my application will down again.
 
This is my infomation on JRockit :
 
Gc Algorithm: JRockit Garbage Collection System currently running strategy: Single generational, parallel mark, parallel sweep.
 
Total Garbage Collection Count: 10340
 
Last GC End: Wed May 10 13:55:37 ICT 2006
 
Last GC Start: Wed May 10 13:55:35 ICT 2006
 
Total Garbage Collection Time: 2:53:13.1
 
GC Handles Compaction: true
 
Concurrent: false
 
Generational: false
 
Incremental: false
 
Parallel: true
 

Hi,
I will suggest you to check a few places where you can see the status
1) SM37 job log (In source system if load is from R/3 or in BW if its a datamart load) (give request name) and it should give you the details about the request. If its active make sure that the job log is getting updated at frequent intervals.
Also see if there is any 'sysfail' for any datapacket in SM37.
2) SM66 get the job details (server name PID etc from SM37) and see in SM66 if the job is running or not. (In source system if load is from R/3 or in BW if its a datamart load). See if its accessing/updating some tables or is not doing anything at all.
3) RSMO see what is available in details tab. It may be in update rules.
4) ST22 check if any short dump has occured.(In source system if load is from R/3 or in BW if its a datamart load)
5) SM58 and BD87 for pending tRFCs and IDOCS.
Once you identify you can rectify the error.
If all the records are in PSA you can pull it from the PSA to target. Else you may have to pull it again from source infoprovider.
If its running and if you are able to see it active in SM66 you can wait for some time to let it finish. You can also try SM50 / SM51 to see what is happening in the system level like reading/inserting tables etc.
If you feel its active and running you can verify by checking if the number of records has increased in the data tables.
SM21 - System log can also be helpful.
Also RSA7 will show LUWS which means more than one record.
Thanks,
JituK

Remove / unload external swf file(s) from the main flash file and load a new swf file and garbage collection from memory.

I can't seem to remove / unload the external swf files e.g when the carousel.swf (portfolio) is displayed and I press the about button the about content is overlapping the carousel (portfolio) . How can I remove / unload an external swf file from the main flash file and load a new swf file, while at the same time removing garbage collection from memory?
This is the error message(s) I am receiving: "TypeError: Error #2007: Parameter child must be non-null.
at flash.display::DisplayObjectContainer/removeChild()
at index_fla::MainTimeline/Down3()"
import nl.demonsters.debugger.MonsterDebugger;
var d:MonsterDebugger=new MonsterDebugger(this);
stage.scaleMode=StageScaleMode.NO_SCALE;
stage.align=StageAlign.TOP_LEFT;
stage.addEventListener(Event.RESIZE, resizeHandler);
// loader is the loader for portfolio page swf
var loader:Loader;
var loader2:Loader;
var loader3:Loader;
var loader1:Loader;
// resize content
function resizeHandler(event:Event):void {
    // resizes portfolio page to center
loader.x = (stage.stageWidth - loader.width) * .5;
loader.y = (stage.stageHeight - loader.height) * .5;
// resizes about page to center
loader3.x = (stage.stageWidth - 482) * .5 - 260;
loader3.y = (stage.stageHeight - 492) * .5 - 140;
/*loader2.x = (stage.stageWidth - 658.65) * .5;
loader2.y = (stage.stageHeight - 551.45) * .5;*/
addEventListener(Event.ENTER_FRAME, onEnterFrame,false, 0, true);
function onEnterFrame(ev:Event):void {
var requesterb:URLRequest=new URLRequest("carouselLoader.swf");
loader = null;
loader = new Loader();
loader.name ="carousel1"
//adds gallery.swf to stage at begining of movie
loader.contentLoaderInfo.addEventListener(IOErrorEvent.IO_ERROR, ioError);
function ioError(event:IOErrorEvent):void {
trace(event);
try {
loader.load(requesterb);
} catch (error:SecurityError) {
trace(error);
addChild(loader);
loader.x = (stage.stageWidth - 739) * .5;
loader.y = (stage.stageHeight - 500) * .5;
// stop gallery.swf from duplication over and over again on enter frame
removeEventListener(Event.ENTER_FRAME, onEnterFrame);
//PORTFOLIO BUTTON
//adds eventlistner so that gallery.swf can be loaded
MovieClip(root).nav.portfolio.addEventListener(MouseEvent.MOUSE_DOWN, Down, false, 0, true);
function Down(event:MouseEvent):void {
// re adds listener for contact.swf and about.swf
MovieClip(root).nav.info.addEventListener(MouseEvent.MOUSE_DOWN, Down1, false, 0, true);
MovieClip(root).nav.about.addEventListener(MouseEvent.MOUSE_DOWN, Down3, false, 0, true);
//unloads gallery.swf from enter frame if users presses portfolio button in nav
var requester:URLRequest=new URLRequest("carouselLoader.swf");
    loader = null;
loader = new Loader();
loader.name ="carousel"
loader.contentLoaderInfo.addEventListener(IOErrorEvent.IO_ERROR, ioError);
function ioError(event:IOErrorEvent):void {
trace(event);
try {
loader.load(requester);
} catch (error:SecurityError) {
trace(error);
addChild(loader);
loader.x = (stage.stageWidth - 739) * .5;
loader.y = (stage.stageHeight - 500) * .5;
removeChild( getChildByName("about") );
removeChild( getChildByName("carousel1") );
// remove eventlistner and prevents duplication of gallery.swf
MovieClip(root).nav.portfolio.removeEventListener(MouseEvent.MOUSE_DOWN, Down);
//INFORMATION BUTTON
//adds eventlistner so that info.swf can be loaded
MovieClip(root).nav.info.addEventListener(MouseEvent.MOUSE_DOWN, Down1, false, 0, true);
function Down1(event:MouseEvent):void {
//this re-adds the EventListener for portfolio so that end user can view again if they wish.
MovieClip(root).nav.portfolio.addEventListener(MouseEvent.MOUSE_DOWN, Down, false, 0, true);
MovieClip(root).nav.about.addEventListener(MouseEvent.MOUSE_DOWN, Down3, false, 0, true);
var requester:URLRequest=new URLRequest("contactLoader.swf");
loader2 = null;
loader2 = new Loader();
loader2.name ="contact"
loader2.contentLoaderInfo.addEventListener(IOErrorEvent.IO_ERROR, ioError);
function ioError(event:IOErrorEvent):void {
trace(event);
try {
loader2.load(requester);
} catch (error:SecurityError) {
trace(error);
addChild(loader2);
loader2.x = (stage.stageWidth - 658.65) * .5;
loader2.y = (stage.stageHeight - 551.45) * .5;
// remove eventlistner and prevents duplication of info.swf
MovieClip(root).nav.info.removeEventListener(MouseEvent.MOUSE_DOWN, Down1);
//ABOUT BUTTON
//adds eventlistner so that info.swf can be loaded
MovieClip(root).nav.about.addEventListener(MouseEvent.MOUSE_DOWN, Down3, false, 0, true);
function Down3(event:MouseEvent):void {
//this re-adds the EventListener for portfolio so that end user can view again if they wish.
MovieClip(root).nav.portfolio.addEventListener(MouseEvent.MOUSE_DOWN, Down, false, 0, true);
MovieClip(root).nav.info.addEventListener(MouseEvent.MOUSE_DOWN, Down1, false, 0, true);
var requester:URLRequest=new URLRequest("aboutLoader.swf");
loader3 = null;
loader3 = new Loader();
loader3.name ="about"
loader3.contentLoaderInfo.addEventListener(IOErrorEvent.IO_ERROR, ioError);
function ioError(event:IOErrorEvent):void {
trace(event);
try {
loader3.load(requester);
} catch (error:SecurityError) {
trace(error);
addChild(loader3);
loader3.x = (stage.stageWidth - 482) * .5 - 260;
loader3.y = (stage.stageHeight - 492) * .5 - 140;
removeChild( getChildByName("carousel") );
removeChild( getChildByName("carousel1") );
// remove eventlistner and prevents duplication of info.swf
MovieClip(root).nav.about.removeEventListener(MouseEvent.MOUSE_DOWN, Down3);
stop();

Andrei1,
Thank you for the helpful advice. I made the changes as you suggested but I am receiving a #1009 error message even though my site is working the way I wan it to work. I would still like to fix the errors so that my site runs and error free. This is the error I am receiving:
"TypeError: Error #1009: Cannot access a property or method of a null object reference."
I'm sure this is not the best method to unload loaders and I am guessing this is why I am receiving the following error message.
     loader.unload();
     loader2.unload();
     loader3.unload();
I also tried creating a function to unload the loader but received the same error message and my portfolio swf was not showing at all.
     function killLoad():void{
     try { loader.close(); loader2.close; loader3.close;} catch (e:*) {}
     loader.unload(); loader2.unload(); loader3.unload();
I have a question regarding suggestion you made to set Mouse Event to "null". What does this do setting the MouseEvent do exactly? Also, since I've set the MouseEvent to null do I also have to set the loader to null? e.g.
---- Here is my updated code ----
// variable for external loaders
var loader:Loader;
var loader1:Loader;
var loader2:Loader;
var loader3:Loader;
// makes borders resize with browser size
function resizeHandler(event:Event):void {
// resizes portfolio page to center
     loader.x = (stage.stageWidth - loader.width) * .5;
     loader.y = (stage.stageHeight - loader.height) * .5;
// resizes about page to center
     loader3.x = (stage.stageWidth - 482) * .5 - 260;
     loader3.y = (stage.stageHeight - 492) * .5 - 140;
//adds gallery.swf to stage at begining of moviie
     Down();
//PORTFOLIO BUTTON
//adds eventlistner so that gallery.swf can be loaded
     MovieClip(root).nav.portfolio.addEventListener(MouseEvent.MOUSE_DOWN, Down, false, 0, true);
function Down(event:MouseEvent = null):void {
// re adds listener for contact.swf and about.swf
     MovieClip(root).nav.info.addEventListener(MouseEvent.MOUSE_DOWN, Down1, false, 0, true);
     MovieClip(root).nav.about.addEventListener(MouseEvent.MOUSE_DOWN, Down3, false, 0, true);
//unloads gallery.swf from enter frame if users presses portfolio button in nav
     var requester:URLRequest=new URLRequest("carouselLoader.swf");
     loader = new Loader();
     loader.contentLoaderInfo.addEventListener(IOErrorEvent.IO_ERROR, ioError);
     function ioError(event:IOErrorEvent):void {
     trace(event);
     try {
     loader.load(requester);
     } catch (error:SecurityError) {
     trace(error);
     this.addChild(loader);
     loader.x = (stage.stageWidth - 739) * .5;
     loader.y = (stage.stageHeight - 500) * .5;
// sure this is not the best way to do this - but it is unload external swfs
     loader.unload();
     loader2.unload();
     loader3.unload();
// remove eventlistner and prevents duplication of gallery.swf
     MovieClip(root).nav.portfolio.removeEventListener(MouseEvent.MOUSE_DOWN, Down);
//INFORMATION BUTTON
     //adds eventlistner so that info.swf can be loaded
     MovieClip(root).nav.info.addEventListener(MouseEvent.MOUSE_DOWN, Down1, false, 0, true);
     function Down1(event:MouseEvent = null):void {
     //this re-adds the EventListener for portfolio so that end user can view again if they wish.
     MovieClip(root).nav.portfolio.addEventListener(MouseEvent.MOUSE_DOWN, Down, false, 0, true);
     MovieClip(root).nav.about.addEventListener(MouseEvent.MOUSE_DOWN, Down3, false, 0, true);
     var requester:URLRequest=new URLRequest("contactLoader.swf");
     loader2 = null;
     loader2 = new Loader();
     loader2.contentLoaderInfo.addEventListener(IOErrorEvent.IO_ERROR, ioError);
     function ioError(event:IOErrorEvent):void {
     trace(event);
     try {
     loader2.load(requester);
}      catch (error:SecurityError) {
     trace(error);
     addChild(loader2);
     loader2.x = (stage.stageWidth - 658.65) * .5;
     loader2.y = (stage.stageHeight - 551.45) * .5;
loader.unload();
loader2.unload();
loader3.unload();
     // remove eventlistner and prevents duplication of info.swf
     MovieClip(root).nav.info.removeEventListener(MouseEvent.MOUSE_DOWN, Down1);
//ABOUT BUTTON
     //adds eventlistner so that info.swf can be loaded
     MovieClip(root).nav.about.addEventListener(MouseEvent.MOUSE_DOWN, Down3, false, 0, true);
     function Down3(event:MouseEvent = null):void {
     //this re-adds the EventListener for portfolio so that end user can view again if they wish.
     MovieClip(root).nav.portfolio.addEventListener(MouseEvent.MOUSE_DOWN, Down, false, 0, true);
     MovieClip(root).nav.info.addEventListener(MouseEvent.MOUSE_DOWN, Down1, false, 0, true);
     var requester:URLRequest=new URLRequest("aboutLoader.swf");
     loader3 = null;
     loader3 = new Loader();
     loader3.contentLoaderInfo.addEventListener(IOErrorEvent.IO_ERROR, ioError);
     function ioError(event:IOErrorEvent):void {
     trace(event);
     try {
     loader3.load(requester);
}      catch (error:SecurityError) {
     trace(error);
     addChild(loader3);
     loader3.x = (stage.stageWidth - 482) * .5 - 260;
     loader3.y = (stage.stageHeight - 492) * .5 - 140;
     loader.unload();
     loader2.unload();
     loader3.unload();
     // remove eventlistner and prevents duplication of info.swf
     MovieClip(root).nav.about.removeEventListener(MouseEvent.MOUSE_DOWN, Down3);
     stop();

Garbage collection Java Virtual Machine : Hewlett-Packard Hotspot release 1.3.1.01

"Hi,
I try and understand the mechanism of garbage collection of the Java Virtual Machine : Hewlett-Packard Hotspot release 1.3.1.01.
There is description of this mechanism in the pdf file : "memory management and garbage collection" available at the paragraph "Java performance tuning tutorial" at the page :
http://h21007.www2.hp.com/dspp/tech/tech_TechDocumentDetailPage_IDX/1,1701,1607,00.html
Regarding my question :
Below is an extract of the log file of garbage collections. This extract has 2 consecutive garbage collections.
(each begins with "<GC:").
<GC: 1 387875.630047 554 1258496 1 161087488 0 161087488 20119552 0 20119552
334758064 238778016 335544320
46294096 46294096 46399488 5.319209 >
<GC: 5 387926.615209 555 1258496 1 161087488 0 161087488 0 0 20119552
240036512 242217264 335544320
46317184 46317184 46399488 5.206192 >
There are 2 "full garbage collections", one of reason "1" and one of reason "5".
For the first one "Old generation After " =238778016
For the second "Old generation After " =238778016
Thus, "Old generation Before garbage collection" of the second is higher than "Old generation After garbage collection". Why?
I expected all objects to be allocated in the "Eden" space. And therefore I did not expect to s

I agree but my current Hp support is not very good on JVM issues.
Rob Woollen <[email protected]> wrote:
You'd probably be better off asking this question to HP.
-- Rob
Martial wrote:
The object of this mail is the Hewlett-Packard 1.3.1.01 Hotspot JavaVirtual Machine
release and its garbage collection mechanism.
I am interested in the "-Xverbosegc" option for garbage collectionmonitoring.
I have been through the online document :
http://www.hp.com/products1/unix/java/infolibrary/prog_guide/java1_3/hotspot.html#-Xverbosegc
I would like to find out more about the garbage collection mechanismand need
further information to understand the result of the log file generatedwith the
"-Xverbosegc"
For example here is an extract of a garbage collection log file generatedwith
Hewlett-Packard Hotspot Java Virtual Machine. Release 1.3.1.01.
These are 2 consecutive rows of the files :
<GC: 5 385565.750251 543 48 1 161087488 0 161087488 0 0 20119552 264184480255179792
335544320 46118384 46118384 46137344 5.514721 >
<GC: 1 385876.530728 544 1258496 1 161087488 0 161087488 20119552 020119552 334969696
255530640 335544320 46121664 46106304 46137344 6.768760 >
We have 2 full garbage collections, one of Reason 5 and the next oneof Reason
1.
What happened between these 2 garbage collections as we got : "Oldgeneration
After" of row 2 is higher than "Old generation Before" of row 1? Iexpected Objects
to be initially allocated in eden and so we could not get "old generation2modified
between the end of one garbage collection and before the next one.
Could you please clarify this issue and/or give more information aboutgarbage
collection mechanisms with the Hewlett-Packard Hotspot Java VirtualMachine. Release
1.3.1.01.

Howto Force Garbage Collection manually in Oracle Application Server

Hi,
I have a Oracle SOA suite installed on Oracle 10g Application Server. The heap memory for the SOA oc4j container is 2G with a permgen space of 256M. But it looks like there is some memory leak somewhere and the Heap area is getting filled frequently and this causes an *[libopmnoc4j] OC4J ping attempt timed out* and as a result of this the SOA oc4j container gets restarted automatically.
Is there any means by which we can force a Garbage Collection manually so that this automatic restart does not happen.
Kindly let me know if it is possible to trigger a Garbage Collection manually in Oracle Application Server.
Thanks,
Vijay.

We had a similar situation where the oc4j instance will throw OutOfMemoryException and opmn will restart a new instance every 10-12 hours. The JDBC 10.2.0.3 driver has a memory leak in the XA Resource classes. There is a fix available in metalink.

Manual garbage collection

Im running a huge combinatorial generation algorithm and i'm starting to run into memory allocation errors on larger problem instances. I am using the -Xmx256m run time option on the JVM to give it more memory but im generating huge masses off stuff here.
The question I have is, if I know an object isnt going to be used again is it worth destroying it in memory yourself; i assume if you have some undesired object you can do something like this;
myObject = null;
and then call the garbage collector to free up the memory..firstly will this work, secondly what is there performance tradeoff for calling the garbage collector more often and lastly is the garbage collector allready efficient enough that doing things like this is probably not worth it.
Regards,
Dave

Setting references to null MAY help get immediate relief, but its not guarunteed to help. Same with the System.gc() call.
Doing both those thing will not enable the system to operate with less memory than before, as variables that are out of scope will be discovered during garbage collection, and garbage collection WILL run when the heap is fully utilized.
Doing the above may make the GC pause lower at the expense of worse performance.
Instead of doing the above, I'd recommand using the Incremental GC by specifying -Xincgc on the command line. This will run GC more often in the background, leading to shorter GC pauses, but about 10% performance hit in general.
If OTOH you are running into OutOfMemoryErrors and don't think you should be, you probably have a memory leak. Most likely you are allocating objects and storing them somewhere then forgetting about them. For example, if you stick an object in a HashMap, and then forget about it, that object will not be GC'd, unless the HashMap can be GC'd.

No garbage collection data/detailed memory use data in Wily?

Hi All,
We are running some portals on AIX (1.4.2 SR12). We have installed the wily agent on the portals and the enterprise manager on our solman server. When looking in the introscope workstation the heap usage of the JVMs are shown as it should. However, the J2EE GC Overview 1/2 & 2/2 don't show any detailed data regarding garbage collection and memory usage (e.g. tenured; eden; etc...). At this moment we use IBM PMAT for memory analysis, but this is not real time. We would like to see memory details real time using Wily.
Does anyone else also encounters this problem?
Any suggestions?
Thanks,
Bart.

Hello Amit
Can you please open new thread for your question ?
People won't check this thread to answer your question because the thread is marked "answered".
Kind regards
Tom

Does 5.1 log garbage collection like 4.5.2?

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