Slow or Hung Application
The SystemOut.log contains entries of:
WSVR0605W: Thread <threadname> has been active for <time> and may be hung. There are <totalthreads> in total in the server that may be hung.Recommendations
Review the WSVR0605W stacks
The WSVR0605W stacks are good hints of where the issue
might be.
Automatically generate thread dumps
Enable javacore thread dumps to be generated when a hung thread has been detected.
Open a Support Case
Analyzing thread dumps requires a certain level of proficiency with tooling. If no one at the organization knows how to analyze the thread dump open a support case with IBM Support who can provide the data analysis necessary to help pinpoint where the hang occurred, although note that you are only entitled to product defect search rather than general troubleshooting or performance tuning.
Strategy 1: Ran out of disk space OR Slow file system I/O OR Anti-Virus Protection OR Active backup
A thread dump (javacore) shows a lot of threads in a stack that looks like
"WebContainer : 89" daemon prio=10 tid=0x01683c58 runnable (0x73f7d000..0x73f7faf0)
at java.io.FileOutputStream.writeBytes(Native Method)
at java.io.FileOutputStream.write(FileOutputStream.java:260)
at com.ibm.ejs.ras.WrappingFileOutputStream.write(WrappingFileOutputStream.java:364)
- locked (0x97ff0230) (a com.ibm.ejs.ras.WrappingFileOutputStream)
at java.io.PrintStream.write(PrintStream.java:412)Threads in java.io.FileOutputStream.writeBytes
Strategy 2: JDBC Connection Pool hang
Strategy 3: Check trace levels
It is not unusual for someone to enable trace, then not turn it off.
Strategy 4: Check PMI levels
It is not unusual for someone to enable all PMI counters which can severely degrade performance. Enable only the PMI metrics necessary to gauge the health of the system.