Intelligent Management - Use centralized logging to diagnose problems

Use centralized logging to enable mustGather traces and follow the flow of a request through both the ODR and application server tiers.

• Centralized logging is a tool to help collect the data necessary for troubleshooting and diagnosing a problem. However, for performance reasons, the features of centralized logging are not enabled all the time. Therefore, enable the centralized logging features when we anticipate capturing a particular problem.

• When we run the mustgather.py script, trace specifications are overwritten. To restore the trace specifications, save the trace strings before running the script.

• If we use the remote log collection feature of the mustgather.py script, ensure that your target file system has the appropriate amount of space necessary to contain the gathered log files.

Using centralized logging, we can enable tracing based on the type of problem that you experience, for example, 503 HTTP response codes. With centralized logging, specific types of mustGather documents can be identified by predefined strings. Some examples of predefined mustGather documents include application editioning, 404 error and 503 response codes, health monitoring, and more.

We can also enable rule-based tracing which allows us to set trace strings based on the content of a request when the request arrives

Run the mustgather.py script to enable tracing, collect mustGather documents, and disable tracing. Depending on the mustgather type, different trace strings will be set on appropriate servers in the cell. When the logs are collected by the script, the logs will be retrieved to the system where the script runs. The supported commands are included in the following list:

enable [mustgatherType]	Enable tracing
collect [mustgatherType] [destination]	Collects a specific type of mustGather document
disable [mustgatherType]	Disables tracing

Tasks

1. Determine the type of mustGather document needed. The supported types of mustGather documents are included in the following list:

   404	404 HTTP response code
   503	503 HTTP response code
   504	504 HTTP response code
   agent	node agent
   appedition	Application edition manager
   apc	Application placement controller
   arfm	Autonomic request flow manager
   dc	Dynamic cluster
   hadmgr	High availability deployment manager
   hmm	Health monitoring
   odr	On demand router
   operations	Visualization issues with the Extended Deployment and Operations tabs
   reports	Visualization issues with the Reports tab
   reportsPerf	Visualization issues with performance data displayed on the Reports tab
   repository	Extended Repository Service
   sip	SIP request routing

2. Run the enable command with the appropriate mustGather type specified to set the appropriate tracing on all relevant servers in the cell.
   wsadmin -lang jython -f c:\WebSphere\AppServer\bin\mustgather.py enable 404

3. Recreate the desired scenario.

4. Run the collect command with the appropriate mustGather type and a destination file specified to collect the local and remote mustGather documents.
   wsadmin -lang jython -f c:\WebSphere\AppServer\bin\mustgather.py collect 404 "c:\\mydocs\\collection.zip"

5. Run the disable command with the appropriate mustGather type specified. Running this command sets the trace to *=info on all relevant servers in the cell.
   wsadmin -lang jython -f c:\WebSphere\AppServer\bin\mustgather.py disable 404

Enable Trace Based on Specific Request Content

Intelligent Management: HTTP operands