DCMT DISPLAY TIME Command Usage

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DCMT DISPLAY TIME Command Usage

About System Time

DCMT DISPLAY TIME displays the following system time information:

Field	Value
Current Time	Current time of day in the form hh:mm:ss.ff, where hh is hours based on a 24-hour clock, mm is minutes, ss is seconds, and ff is hundredths of a second.
Current Date	Current date in the form yy/ddd, where yy is the year and ddd is the day.
Startup Time	Startup time in the form hh:mm:ss.ff.
Startup Date	Startup date in the form yy/ddd.
Runaway Intv	The amount of time, in real-time seconds, that a task can run without doing any I/O, before it is considered a runaway task.
Stall	The number of real-time seconds a task can wait before being considered stalled.
Quiesce wait	The number of seconds that a task waits on a quiesce operation before being cancelled. OFF specifies that tasks are not to be terminated due to quiesce waits. STALL INTERVAL specifies that the quiesce wait time for a task is the same as its stall interval.
Timer	The number of real-time seconds between ticks of the internal clock.
Recovery wait	The number of seconds that the system is to permit a task to wait for a resource to be recovered by a failed data sharing group member before abnormally terminating the task. NOT ALLOWED (or 0) directs the system to immediately cancel the task. FOREVER directs the system to permit a task to wait indefinitely.
Resource Intv	The number of real-time seconds that a task can wait for a resource before the resource timeout program is run.
Resource Prog	The name of the resource timeout program that runs if a task waits too long for a resource.

About Time-Initiated Tasks

DCMT DISPLAY TIME TASKS displays the following information for all time-initiated tasks pending execution:

Field	Value
TaskID	The task codes of all time initiated tasks pending execution
Time	The time at which each time initiated task begins execution, in the form hh:mm:ss
Date	The date at which each time initiated task begins execution, in the form yy:ddd
UserID	The internal userid associated with the time-initiated task.

More Information

For more information about time-initiated tasks, see the System Generation Guide.

DCMT DISPLAY TRACE Command

The DCMT DISPLAY TRACE command displays the tracing options currently in effect for your system.

DCMT DISPLAY TRACE Syntax

The following diagram shows the syntax for the DCMT DISPLAY TRACE command:

►►─ DCMT ─┬───────────────────┬─ Display TRACe ───────────────────────►◄
          └─ broadcast-parms ─┘

DCMT DISPLAY TRACE Parameters

This section describes the parameters for the DCMT DISPLAY TRACE statement:

broadcast-parms

Executes the DCMT command on all or a list of data sharing group members.

For more information about broadcasting and broadcast-parms syntax, see "How to Broadcast System Tasks" in the System Tasks and Operator Commands Guide.

Example: DCMT DISPLAY TRACE outputs

The following example illustrates the output from a DCMT DISPLAY TRACE command when trace information is not being saved.

DCMT DISPLAY TRACE System tracing (SYSTRACE): ON Trace table size: 20 MB Address: 39A40000 Adjunct table size: 10 MB Address: 36603000 Save: OFF Driver: INACTIVE Area: DDLDCLOG

The following example illustrates the output from a DCMT DISPLAY TRACE command when trace information is being saved to a DDLDCTRC area.

DCMT DISPLAY TRACE System tracing (SYSTRACE): ON Trace table size: 4 KB Address: 39B65000 Adjunct table size: 8 MB (S) Address: 36603000 Save: ON Driver: ACTIVE Area: DDLDCTRC 0% FULL ------------Trace service driver statistics-------------- Driver started.................2009-12-08-12.23.21.151167 Number of save requests................................44 Number of times entries missed..........................2 Bytes/hour........................................1067733 Pages/hour............................................300 Number of reads........................................14 Number of writes........................................9 Number of read waits....................................1 Number of write waits...................................0 Number of page range resets.............................1 Number of area full waits...............................0 Number of errors........................................0 % of waits to I/Os......................................0 Number of RUs...........................................8 Number of look aheads...................................5 % of look aheads to RUs................................63

System Tracing

Potential values are as follows:

ON—System tracing is enabled.
OFF—System tracing is disabled.

Trace table size

The size of the system trace table in kilobytes (KB) or megabytes (MB).

If the characters “(S)” follow table size, it indicates that the contents of the system trace table are being saved.

Address

The address of the system trace table.

Adjunct table size

The size of the adjunct trace table in kilobytes (KB) or megabytes (MB).

If the characters “(S)” follow table size, it indicates that the contents of the adjunct trace table are being saved.

Address

The address of the adjunct trace table.

Save

Potential values are as follows:

ON—Trace saving is enabled.
OFF—Trace saving is disabled.
REQUESTED—Trace saving has been requested but is not yet fully enabled.

Driver

Potential values are as follows:

ACTIVE—Trace service driver is active.
INACTIVE—Trace service driver is inactive.
PENDING—Trace service driver is starting up.

Area

Potential values are as follows:

DDLDCLOG—Trace information is written to the log area.
DDLDCTRC—Trace information is written to the trace area.

% Full

The percentage of space used in the area.

Trace service driver statistics

A header for statistics that are displayed only if trace saving is enabled.

Driver started: The date and time at which the trace service driver was started.
Statistics reset: The date and time when the driver statistics were reset due to overflow.
Number of save requests: The number of requests made to save trace information.
Number of times entries missed: The number of times one or more trace entries were not saved because they had been overlaid before they could be written.
Bytes/hour: The rate at which trace information is being written, specified as bytes per hour.
Pages/hour: The rate at which pages are written to the log or trace area, specified as pages per hour.
Number of reads: The number of pages read from the log or trace area.
Number of writes: The number of pages written to the log or trace area.
Number of read waits: The number of times the driver had to wait for a read to complete.
Number of write waits: The number of times the driver had to wait for a write to complete.
Number of page range resets: The number of times the driver had to recalculate the range of pages into which it can write information.
Number of area full waits: The number of times the driver had to wait for the contents of the log or trace area to be archived.
Number of errors: The number of I/O errors encountered.
% of waits to I/Os: The percent of waits to I/O requests.
Number of RUs: The number of run units currently in use.
Number of look aheads: The number of look ahead reads in effect.
% of look aheads to RUs: The percent of run units being used for look ahead reads.

How to Reduce the Number of Missed Entries

Eliminating missed trace entries can be difficult; however, there are steps you can take to reduce the number of missed entries. In the trace information output, if the value for number of times entries missed is large compared to the value for number of save requests, consider taking one or more of the following actions:

Save trace information to the trace area rather than the log area.
Reduce the amount of trace information being saved. If only extended trace information is of interest, be sure to allocate an adjunct table so only extended trace information is saved.
Increase the size of the trace or adjunct table.
Ensure that the appropriate archive utility is executed often enough that the trace area does not fill. The easiest way to do this is to automate the submission of the archive job using a WTO exit.