Choosing and using diagnosis tools and controls on z/OS

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

Before you begin

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

Note: This topic references one or more of the application server log files. As a recommended alternative, you can configure the server to use the High Performance Extensible Logging (HPEL) log and trace infrastructure instead of using SystemOut.log , SystemErr.log, trace.log, and activity.log files on distributed and IBM® i systems. You can also use HPEL in conjunction with your native z/OS® logging facilities. If you are using HPEL, you can access all of your log and trace information using the LogViewer command-line tool from your server profile bin directory. See the information about using HPEL to troubleshoot applications for more information on using HPEL.

About this task

When your 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 your environment. Each tool has functions specific to different parts of the product, and they can be used in concert to help you better diagnose your problems.

Procedure

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) that are 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 you work with IBM Support personnel, you might be asked to supply the error log so that service personnel can use these support messages to help diagnose the problem.

You must update the CFRM policy before using log streams that are CF-resident, such as the WebSphere® error log and RRS logs.
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 Using RMF for instructions on starting and using RMF to monitor your 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 Redbooks library to access books about MVS diagnosis.