(ZOS) Choosing and using diagnosis tools and controls on z/OS

The following is a description of the types of tools and controls we can use for diagnosing and managing problems in the product environment.

The product uses a variety of different tools and server controls to help collect specific types of data to determine where the servers are encountering problems. To efficiently use these tools we need to be aware of the different functions each can provide and what type of information will be available from each.

IBM recommends using the High Performance Extensible Logging (HPEL) log and trace infrastructure . We view HPEL log and trace information using the logViewer .

When wer applications or servers are experiencing problems that may be originating from different sources, use the following tools to collect data and information on processes in the environment. Each tool has functions specific to different parts of the product, and they can be used in concert to help you better diagnose our problems.

Tasks

Use the following z/OS tools to access and work with diagnostic information.

• z/OS console

  The console displays configuration errors that cause the termination of the product address spaces. Whatever goes to the console also goes to SYSLOG.

• System log (SYSLOG)

  SYSLOG is the repository for all messages that have appeared on the operator console. It also contains warning and informational messages that might be helpful after a failure has occurred.

• Job log

  The job log contains errors and warnings (non-termination) related to configuration. Anything that goes to the console and SYSLOG automatically goes to the job log.

• System output (SYSOUT)

  SYSOUT is a batch log that usually contains diagnostic data from the Java Virtual Machine (JVM) that runs in the servant. Any messages written to stderr will end up in SYSOUT. In addition, SYSOUT might contain error messages that usually appear in the log stream, but were redirected to SYSOUT, because the log stream was not available.

• Error log

  The error log contains messages issued through Java logging and JRas support, if any. In addition, the error log usually contains messages that are only intended for IBM use. These messages support actions, problems, or issues that are usually externalized through additional messages that are issued by other functions. When we work with IBM Support personnel, we might be asked to supply the error log so that service personnel can use these support messages to help diagnose the problem.

  We must update the CFRM policy before using log streams that are CF-resident, such as the WebSphere error log and RRS logs. See (ZOS) Update the CFRM policy for details.

• SYSPRINT

  SYSPRINT contains component trace (CTRACE) output for clients, and for servants when the product is configured to use SYSPRINT instead of CTRACE buffers and data sets.

• Component trace (CTRACE) data set

  CTRACE data sets contain diagnostic trace entries for various processes, depending on the trace options configured for the product.

• Logrec

  When an error occurs, the system records information about the error in the logrec data set or the logrec log stream. The information provides you with a history of all hardware failures, selected software errors, and selected system conditions.

• Transaction XA Partner Log

  This log is used for recovery of XA resources. When an application accesses XA resources, the product stores information about the resource to enable XA transaction recovery. For instructions on how to use the Profile Management Tool or the zpmt command to configure the Transaction XA Partner Log see the Customization variables: Stand-alone application server cell topic in the installing your application serving environment section. For instructions on how to change the location of the Transaction XA Partner Log, see the transaction service settings information.

• SDSF

  Use the SDSF DA panel to see how many application server address spaces are active, and observe at the CPU%, ECPU% and SIO rate. Use the "ENC" panel to see the enclaves running and what service classes they are running under.

• RMF™

  See Use RMF for instructions on starting and using RMF to monitor the transactions.

• MODIFY command

  See the getting help for the modify command example documentation for instructions on using the z/OS modify command to display information about the product servers or servants.

To find additional information about these tools, and about the process of diagnosing problems on z/OS, use the z/OS product library to access the following books:

• z/OS MVS Diagnosis: Procedures, GA22-7587, which helps you diagnose problems in the MVS operating system, its subsystems, its components, and in applications running under the system.
• z/OS MVS Diagnosis: Tools and Service Aids, GA22-7589, which provides detailed information about tools and service aids that can help you diagnose problems. This book contains a guide on how to select the appropriate tool or service aid for our purposes, and also provides an overview of all the tools and service aids available.

Subtopics

• Use RMF
  RMF can usually be started with the simple 'S RMF' command from the MVS console.
• Collecting job-related information with the System Management Facility (SMF)
  SMF can be enabled to collect and record system and work-related information on the WebSphere for z/OS system. This information can be used to bill users, report system reliability, analyze the configuration, schedule work, identify system resource usage, and perform other performance-related tasks that our organization may require.
• Run-time environment: Best practices for maintaining the runtime environment
  Use these guidelines to make sure that WAS for z/OS is customized and maintained correctly, to support the installation's application workload.
• System controls: Best practices for using system controls
  Use this information as the best way to configure system controls.
• Performance diagnosis information
  The following report options are listed here for information. IBM Service may request that we run one or more of these reports while assisting you with diagnosis. We do not need to collect this data unless it is requested by IBM Service.
• Update the CFRM policy
  We must update the coupling facility resource management (CFRM) policy before using log streams that are CF-resident, such as the WAS error log and RRS logs. If we have the source for the current active CFRM policy, update the source and use the IXCMIAPU Administrative Data utility to generate the new policy.

• Troubleshoot using WebSphere variables
  Troubleshooting problems can be performed by changing certain variables in the application environment.

Debugging applications

Transaction service settings