Setting JVM ThreadStackSize for error-free Defects/Stats Aggregration operations.

Products

• CA Application Performance Management Agent (APM / Wily / Introscope)
• INTROSCOPE

Issue/Introduction

For most JVMs, setting the specified thread stack size to 192 (-XX:ThreadStackSize=192) for defects and statistical aggregation is sufficient, but there are JVMs which may need more than 256.

Environment

All Supported APM Releases supporting APM CE (CEM).

Resolution

For the instructions below, obtain a copy of TestThreadStackSize.java from https://gist.github.com/rednaxelafx/1066792. This simple Java program sleeps 5 minutes, giving you ample time to use the jinfo JDK utility to discover the default and minimum values needed to successfully invoke a JVM.

How to determine the default thread stack size in a 32-bit JVM

• Execute TestThreadStackSize
  
  
  • # /opt/java7/jre/bin/java TestThreadStackSize
    
    
    • Running/sleeping..... 
      
      
• Get the PID of TestThreadStackSize
  
  
  • # /opt/java7/bin/jps -lvm
    
    
    • 21524 TestThreadStackSize 
      
      
    • 21525 sun.tools.jps.Jps -lvm -Dapplication.home=/opt/java7 -Xms8m 
      
      
  • The PID of TestThreadStackSize is 21524. 
    
    
• Verify the default thread stack size value from the running JVM
  
  
  • # /opt/java7/bin/jinfo -flag ThreadStackSize 21524
    
    
    • -XX:ThreadStackSize=512 
      
      
  • The default thread stack size is 512.

How to determine the minimum required thread stack size in a 32-bit JVM

• Execute TestThreadStackSize with a ThreadStackSize that is too small
  
  
  • # /opt/java7/jre/bin/java -XX:ThreadStackSize=192 TestThreadStackSize
    
    
    • Error: Could not create the Java Virtual Machine. 
      
      
    • Error: A fatal exception has occurred. Program will exit. 
      
      
  • The stack size specified is too small. Specify at least 200k. 
    
    
• Execute TestThreadStackSize with a ThreadStackSize that is sufficient
  
  
  • # /opt/java7/jre/bin/java -Xss200k TestThreadStackSize
    
    
    • Running/Sleeping… 
      
      
  • The stack size specified is sufficient. 
    
    
• Verify the ThreadStackSize specified
  
  
  • # /opt/java7/bin/jps -lvm
    
    
    • 21637 sun.tools.jps.Jps -lvm -Dapplication.home=/opt/java7 -Xms8m 
      
      
    • 21631 TestThreadStackSize -Xss200k 
      
      
  • # /opt/java7/bin/jinfo -flag ThreadStackSize 21631
    
    
    • -XX:ThreadStackSize=400 
      
      
  • The stack size in use is 400.

How to determine the default thread stack size in a 64-bit JVM

• (For HP-UX JVM, add "-d64" to JVM args for 64-bit) 
  
  
• # /opt/java7/jre/bin/java -d64 TestThreadStackSize
  
  
  • Running/sleeping..... 
    
    
• Get the PID of TestThreadStackSize
  
  
  • # /opt/java7/bin/jps -lvm
    
    
    • 21652 sun.tools.jps.Jps -lvm -Dapplication.home=/opt/java7 -Xms

How to specify JVM ThreadStackSize for HP-UX

• Minimum stack size for a 32-bit JVM in HP-UX is 400
  
  
  • -XX:ThreadStackSize=400 
    
    
• When using custom JVMs under HP-UX memory limitation scenarios, we recommended using the standalone Java program TestThreadStackSize to determine the minimum stack size needed. 
  
  
• The alternative is to use trial and error to arrive at an acceptable value for defects and stats aggregation JVM ThreadStackSize when defects and stats aggregation are configured to use a separate JVM. Trail and error may require multiple Enterprise Manager restarts until an acceptable minimum value is achieved based on error messages in the Enterprise Manager logs.