Monthly Archive: December 2010

Different Out Of Memory Issues

* Exception in thread “CompilerThread1” java.lang.OutOfMemoryError: requested 793020 bytes for Chunk::new. Out of swap space?

Out of memory while reading in symbol table of /apps/bea/weblogic92/jdk1.5.0.18/opt/java1.5/jre/lib/PA_RISC2.0/server/libjvm.sl
( 0)  0xc8461230     [/apps/bea/weblogic92/jdk1.5.0.18/opt/java1.5/jre/lib/PA_RISC2.0/server/libjvm.sl]
( 1)  0xc80a5fec     [/apps/bea/weblogic92/jdk1.5.0.18/opt/java1.5/jre/lib/PA_RISC2.0/server/libjvm.sl]
( 2)  0xc7f00420     [/apps/bea/weblogic92/jdk1.5.0.18/opt/java1.5/jre/lib/PA_RISC2.0/server/libjvm.sl]
( 3)  0xc7f00ca0     [/apps/bea/weblogic92/jdk1.5.0.18/opt/java1.5/jre/lib/PA_RISC2.0/server/libjvm.sl]
( 4)  0xc8368d08     [/apps/bea/weblogic92/jdk1.5.0.18/opt/java1.5/jre/lib/PA_RISC2.0/server/libjvm.sl]
( 5)  0xc005b2e4   __pthread_body + 0x44  [/usr/lib/libpthread.1]
( 6)  0xc0065574   __pthread_start + 0x14  [/usr/lib/libpthread.1]
Java out of memory messages are marked with pid: 13828 in /var/adm/syslog/syslog.log.

Possible causes:
– not enough swap space left, or
– kernel parameter MAXDSIZ is very small.

Solution:
Although it appears that an OutOfMemoryError is thrown this apparent exception is reported by the HotSpot VM code when an allocation from the native heap failed and the native heap may be close to exhaustion. The message indicates the size (in bytes) of the request that failed and also indicates what the memory is required for. In some cases the reason will be shown but in most cases the reason will be the name of a source module reporting the allocation failure. If an OutOfMemoryError with this error is thrown it may require using utilities on the operating system to diagnose the issue further. Examples of issues that may not be related to the application are when the operating system is configured with insufficient swap space, or when there is another process on the system that is consuming all memory resources. If neither of these issues is the cause then it is possible that the application is failed due to native leak; for example, application or library code is continuously allocating memory but is not releasing it to the operating system.
For more information: http://java.sun.com/j2se/1.5/pdf/jdk50_ts_guide.pdf

The recommendation for swap space size in the Solaris is that swap should be configured about 30% of physical RAM.

The following link has suggested a workaround to add ‘-XX:+UseDefaultStackSize -Xss256K’ parameter.
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4916142

Add: -XX:CodeCacheMinimumFreeSpace=2M -XX:+ReservedCodeCacheSize=64M -XX:PermSize=128m -XX:MaxPermSize=384m (As per your other JVM settings)

Sun team needs to be involved for this issue. Usually such issues are solved by sun support.

=============================

* java.lang.OutOfMemoryError: unable to create new native thread
at java.lang.Thread.start0(Native Method)
at java.lang.Thread.start(Thread.java:574)
at weblogic.work.RequestManager.createThreadAndExecute(RequestManager.java:271)
at weblogic.work.RequestManager.executeIt(RequestManager.java:245)
at weblogic.work.ServerWorkManagerImpl.schedule(ServerWorkManagerImpl.java:142)

Solution:
1) Set kernel parameter maxdsiz to a higher value
2) Reduce the current heap size.
3) Check the kernel values:  ulimit -a
4) If the NPROC soft limit is lower than the hard limit, increase it as needed: ulimit -u <new value>.
Check the Operating System documentation to make changes permanent at the OS configuration files.
5) Need to reduce the JVM stack size and the OS stack size both. Set the -xss in java options and set ulimit -s on the OS level.

=============================

* java.lang.OutOfMemoryError: PermGen space
at java.lang.Class.getDeclaredConstructors0(Native Method)
at java.lang.Class.privateGetDeclaredConstructors(Unknown Source)
at java.lang.Class.getConstructor0(Unknown Source)
at java.lang.Class.getConstructor(Unknown Source)

Solution: Increase the max permgen space -XX:MaxPermSize=256m

There can be a leak in the permgen objects. If tuning parameters do not resolve the issue, we need to use the memory leak detector tools and find out which instances in the permgen space are not getting cleared.

=============================

* java.lang.OutOfMemoryError: allocLargeObjectOrArray – Object size: 372032, Num elements: 372012
* java.lang.outofmemoryerror: nativeGetNewTLA

Solution: -XXtlasize:128k -XXlargeobjectlimit:128k

If this does not solve the issue, we need to check in the application code for the large objects being created and not being destroyed. Take JRA Recording (Oracle JRockit) or use JConsole and memory leak detector tools (JMAP, JHAT) for analysis on the

=============================

* java.lang.OutOfMemoryError: Java Heap Space

Solution: First thing that needs to be checked is the gc logs. Need to check whether the garbage collection is happening properly. If the heap keeps gradually increasing even after full gc, tune the gc algorithms and check if the behavior is the same. Use memory leak detector tools for both sun jdk and JRockit to check which instances from the application are not getting destroyed.

If this is not the case and the application genuinely needs more memory, increase the heap size by using the parameters:
Example: -Xms2048m -Xmx2048m

=============================

* java.lang.StackOverflowError

Solution: Stack over flow error is usually generated due to a recursive call made by the application (infinite recursion), or its because of an attempt to allocate more memory on the stack than will fit. This is usually the result of creating local array variables that are far too large for the current stack.

For the first possibility, we need to check the application code as to where is the recursive call being made.
For the second possibility, we can increase the JVM stack size by the parameter : Example: -Xss512K

=============================

java.lang.OutOfMemoryError: GC overhead limit exceeded.
java.lang.OutOfMemoryError: GC overhead limit exceeded
at java.util.Arrays.copyOfRange(Arrays.java:3209) 

Try adding this jvm option
-XX:-UseGCOverheadLimit

 

Integrate YourKit Java Profiler with a standalone Weblogic Server

YourKit Java Profiler is a CPU and memory profiler that makes it easy to solve wide range of CPU- and memory-related performance problems. It features automatic leak detection, powerful tools for the analysis of memory distribution, an object heap browser, comprehensive memory tests as part of your JUnit testing process, extremely low profiling overhead, transparent deobfuscation support, and integration with Eclipse, JBuilder, IntelliJ IDEA, NetBeans, and JDeveloper IDEs
Ref: – http://freshmeat.net/projects/yjp/
Download the trail version from here
http://www.yourkit.com/download/index.jsp

Steps to integrate it with Weblogic Server

Integrate with standalone J2EE Server

Select Weblogic 9/10

Browse to the location where the startup script is.

Select the startup script; this will create the startup script for the Profiler

Start your server using that script
C:\bea103\user_projects\domains\First_Domain\bin\startWebLogic_with_yjp

You will see it in the running JVM’s list. Click on it.

You should be able to see the Memory usage stats

Garbage collection activity

Class Loading activity

I am yet to explore the tool and see how I can use it for the maximum benefit.
Looks to me it combines the feature of gcviewer, eclipse memory analyzer and JProbe.
“Good to have” tool in a support engineers armory! 😉

Creating Datasource using WLST

connect(‘weblogic’,’weblogic’,’t3://localhost:7001′)
edit()
startEdit()
cd(‘/’)
cmo.createJDBCSystemResource(‘PegaRULES’)
cd(‘/JDBCSystemResources/PegaRULES/JDBCResource/PegaRULES’)
cmo.setName(‘PegaRULES’)
cd(‘/JDBCSystemResources/PegaRULES/JDBCResource/PegaRULES/JDBCDataSourceParams/PegaRULES’)
set(‘JNDINames’,jarray.array([String(‘jdbc/PegaRULES’)], String))
cd(‘/JDBCSystemResources/PegaRULES/JDBCResource/PegaRULES/JDBCDriverParams/PegaRULES’)
cmo.setUrl(‘jdbc:sqlserver://localhost:1433’)
cmo.setDriverName(‘com.microsoft.sqlserver.jdbc.SQLServerDriver’)
cmo.setPassword(‘pega612’)
cd(‘/JDBCSystemResources/PegaRULES/JDBCResource/PegaRULES/JDBCConnectionPoolParams/PegaRULES’)
cmo.setTestTableName(‘SQL SELECT 1\r\n\r\n’)
cd(‘/JDBCSystemResources/PegaRULES/JDBCResource/PegaRULES/JDBCDriverParams/PegaRULES/Properties/PegaRULES’)
cmo.createProperty(‘user’)
cd(‘/JDBCSystemResources/PegaRULES/JDBCResource/PegaRULES/JDBCDriverParams/PegaRULES/Properties/PegaRULES/Properties/user’)
cmo.setValue(‘pega612’)
cd(‘/JDBCSystemResources/PegaRULES/JDBCResource/PegaRULES/JDBCDriverParams/PegaRULES/Properties/PegaRULES’)
cmo.createProperty(‘databaseName’)
cd(‘/JDBCSystemResources/PegaRULES/JDBCResource/PegaRULES/JDBCDriverParams/PegaRULES/Properties/PegaRULES/Properties/databaseName’)
cmo.setValue(‘prpc612’)
cd(‘/JDBCSystemResources/PegaRULES/JDBCResource/PegaRULES/JDBCDataSourceParams/PegaRULES’)
cmo.setGlobalTransactionsProtocol(‘OnePhaseCommit’)
cd(‘/SystemResources/PegaRULES’)
set(‘Targets’,jarray.array([ObjectName(‘com.bea:Name=AdminServer,Type=Server’)], ObjectName))
activate()
dumpStack()
exit()