Performance troubleshooting tips


Problem Tuning parameters
General response time Hardware capacity and settings
ORB response time and throughput indicate EJB requests with shorter execution times are being denied adequate access to threads in ORB thread pool. ORB service settings that can be added to the LPD mechanism
Solaris: Too many files open Operating systems
Solaris operating environment: The server stalls during peak periods, responses take minutes, processor utilization remains high with all activity in the system processes, and netstat shows many sockets are open to port 80 in CLOSE_WAIT or FIN_WAIT_2 state. Operating systems
The Percent Maxed metric from the TPV indicates that the Web container thread pool is too large or too small. Thread pool Maximum size
Netstat shows too many TIME_WAIT state sockets for port 9080. MaxKeepAliveConnections and MaxKeepAliveRequests
Too much disk input and output occurs due to paging. Maximum heap size
The Percent Used metric for a data source connection pool from the TPV indicates the pool size is too large. Maximum connection pool and Minimum connection pool
The Prepared Statement Discards metric from the TPV indicates that the data source statement cache size is too small. Statement cache size
Too much disk input and output occurs due to DB2 writing log records. DB2 MinCommit
The Percent Maxed metric from the TPV indicates that the ORB thread pool is too small. EJB method Invocation Queuing
JVMPI indicates over-utilization of objects when too much time is spent in garbage collection. Detecting over-utilization of objects
The Used Memory metric from the TPV shows memory leaks and the Java code displays an Out of Memory exception. Detecting memory leaks
Throughput, response time and scalability are undesirable. If the application permits, exploit the dynamic cache service
Startup performance is poor. Using JVM settings, set a minimum heap size of at least 50MB (-Xms50m).


See Also

  1. 100% CPU usage
  2. PMI/performance tools
  3. performance parameter index
  4. Web server tuning parameters