Scorpion's Corner

Common Reasons for Out Of Memory Errors

Out Of Memory error can happen due to following reasons:

• Garbage Collection Issues


• Orphaned Class loaders
  
  
  
  • Thread context classloader
  
  
  • new Thread()
  
  
  • Dangling thread
  
  
  
  


• Classes with following references
  
  
  
  • static variables
  
  
  • SQL Driver
  
  
  • Commons logging
  
  
  • java.util.logging.Level
  
  
  • Bean util
    
    
    
    • Details
    
    
    
    
  
  
  
  

etc..

We can analyze the problem(s) associated with such errors at application level by having GC details and/or heap dump

• -verbose:gc with -XX:+PrintGCDetails for observing GC model for tuning or altering suitable GC for the application


• -XX:+HeapDumpOnOutOfMemoryError


• -Xrunhprof:heap=dump,format=b


• jmap -dump:format=b,file=heap.bin <pid>
  

Analyze heap dump using Jhat

• jhat -J-mx1024m heap.bin


• http://localhost:7000


• Using built-in or custom queries to narrow down leak suspects


• Identify an object or class in the application


• List reference chains

Posted at 10:58PM Sep 16, 2008 by Narayana Rallabandi in Sun  |  Comments[0]