SYS - System service aids
Various tools, utilities, and traces can help you analyze IMS system problems.
Log records
To diagnose some problems, you need to examine the content of log records to determine what was going on in the system before the problem occurred. By knowing the layout of the log records, you can set up a DFSERA10 job that will produce the specific log records that you need to examine.
Printing log records and trace table entries
You can use the File Select and Formatting Print utility (DFSERA10) to print both log records from the IMS log data set and the externalized trace table entries that are recorded in the DFSTRA
xx
data set.
Log Merge utility
The Log Merge utility can merge up to nine IMS system logs. Each log is the output of a uniquely identified IMS system that is running during the same time span.
Formatting IMS dumps offline
Two methods are available for formatting IMS dumps offline: interactive formatting, performed through a series of panels which provide formatting choices, and formatting by using JCL.
Edited command buffer format
The edited command buffer is logged in the
X'02'
log record and is passed to the AOI user exit. You can use the edited command buffer to determine if any recoverable commands were issued for the resource you are analyzing.
IMS Dump Formatter
The IMS Dump Formatter provides ISPF dialog support for IMS Offline Dump Formatter requests, and simplifies the process of making requests by providing menus for format option selection, help members for online options, automatic terminal and spool output control, and a configuration panel to provide interactive assistance in defining the IMS environment.
Formatting IMS dumps online
One of the tools available for problem diagnosis is the IMS formatted dump, which formats the control blocks and data areas in an IMS region.
SNAP call facility
The SNAP call facility (DFSERA20) produces SNAP dumps of DL/I control blocks and identifies calling routines that generate SNAP dumps. Supervisor call (SVC) dumps are generated only for the intended abend codes or status codes, and for unknown calling routines.
/DIAGNOSE command SNAP function
The
/DIAGNOSE
command SNAP function provides a non-intrusive alternative to creating a console dump. Use of this command can decrease the time that is required to generate problem determination data for
IBM® Software Support
.
Type-1 trace table interface
For each trace, you can learn about the trace identifier, the events that are traced, and, if the trace is documented in this information, the topic where you can find more information. You use the trace identifier as an eye catcher to locate a trace in a dump.
Type-2 trace tables
You can activate IMS type-2 trace tables at IMS startup or while IMS is active. Unlike type-1 trace tables, type-2 trace tables can be updated dynamically using the
UPDATE TRACE
command while IMS is up, and they can be queried to gather diagnostic information.
IMS shutdown trace table
When IMS begins shutdown processing, IMS populates a trace table for the shutdown activity. The shutdown trace table is included in a dump of the IMS control region, and can help you determine which module is preventing IMS shutdown from completing.
Parent topic:
Diagnosis
Related reference
Sequential buffering service aids