E.17 Diagnosing Initialization and Performance Issues

This section includes the following topics:

E.17.1 Diagnosing an Initialization Issue

Problem

OAM Server does not start up.

Solution

Locate and review the OAM Server log file on the computer hosting the OAM Server.
```
 DOMAIN_HOME/servers/SERVER-NAME/logs/SERVER-NAME-diagnostics.log
```
Enable logging for this computer, as described in Logging Component Event Messages:
```
 DOMAIN_HOME/config/fmwconfig/servers/SERVER-NAME/logging.xml
```
Restart the OAM Server, observe the behavior, check the log file again if needed.

E.17.2 Diagnosing a Performance Issue

Problem

Monitoring the OAM Server reveals a significant spike in latency during authentication.

Solution

Locate and review the OAM Server log file on the computer hosting the OAM Server.
```
 DOMAIN_HOME/servers/SERVER-NAME/logs/SERVER-NAME-diagnostics.log
```
Enable logging for this computer, as described in Logging Component Event Messages:
```
 DOMAIN_HOME/config/fmwconfig/servers/SERVER-NAME/logging.xml
```
Restart the OAM Server, observe the behavior, check the log file again if needed.

E.17.3 Diagnosing Out-of-Memory Issues With a Heap Dump

Problem

Debugging for all expression parsing and evaluation produced a significant performance drag within ~20 hours due to memory growth; running out of memory in ~50 hours.

Configuration: 2GB heap; 3 minute session timeout; jdbc connections tuned min=32 max=200; jdbc connection idle timeout disabled; jbo pool size min = 10 & max=150

Solution

To generate heap-dumps for comparison, you use the following command-line tools jmap for Sun jvm or jrcmd for jrockit jvm located under JAVA_HOME/bin.

For jrockit jvm

jrcmd pid <command> 
/jrockit_160_14_R27.6.5-32/bin/jrcmd 16775 heap_diagnostics
/jrockit_160_14_R27.6.5-32/bin/jrcmd 16775 print_threads
/jrockit_160_14_R27.6.5-32/bin/jrcmd 16775 jrarecording ....

For Sun jvm

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