DFHCOMMAREA

input/output

CICS Communication area with the following contents.

TDC-CICS-SYSID

input

CICS SYSID for this invocation. Do not modify.

TDC-MQS-QUEUENAME

input

Name of MQ Queue being processed. Do not modify.

TDC-PARMLIST

input/output

Parameter list structure with the following items:

TDC-MAX-MPL

input/output

Limits the total number of child TDC processes that the TDC spawns against the MQS queue during heavy loads.

Default: 5

The valid range is 1 through the CICS MXT value. Remember that WebSphere MQ dispatches on a maximum of 8 TCBs.

TDC-Q-CHECK-FREQ

input/output

Sets the number of messages the TDC processes before checking queue depth. Accepts a numeric value.

Default: 10

The valid range is 1 through 4095

TDC-Q-DEPTH-PER

input/output

Sets the queue depth threshold at which the TDC spawns a child TDC process.

Default: 20

The valid range is 1 through 4095.

TDC-SLOW-AT-MXT

input/output

Enter slowdown mode when active tasks reach CICS MXT minus TDC-SLOW-AT-MXT.

The TDC enters slowdown mode if it detects a Short-On-Storage condition, or if the current active task count exceeds CICS MXT minus the TDC-SLOW-AT-MXT value. The TDC exits slowdown mode whenever these conditions are resolved.

Note: Setting TDC-SLOW-AT-MXT high may severely affect response time.

Default: 20

The valid range is 1 through CICS MXT value.

TDC-SLOW-INTERVAL

input/output

Defines the amount of time that the TDC waits between starting server managers while in slowdown mode, in seconds.

Default: 2

The valid range is 1 through 359999.

TDC-MQGET-WAITTIME

input/output

Determines the persistence of the parent TDC, the length of time the TDC holds the MQS queue open waiting for a message to arrive, in milliseconds. Setting this to a high value reduces triggering and transaction overhead, but the task remains suspended on the task chain for the duration if no messages are available. This value affects only the parent invocation of the TDC. Spawned child TDCs wait for messages for one second regardless of this setting.

Default: 5000

The valid range is 0 through 268435455 milliseconds

TDC-OVERIDE-USERID

input/output

Override user ID for CA Gen transactions. The default is blank, but you can set it to any valid user ID.

If you use this parameter, set the TDC-SECURITY-MODE parameter to O.

TDC-VSAM-DDNAME

input/output

VSAM file DDNAME. By default, this parameter is TITDTEMP, but you can set it to any CICS-supported 8 character name.

Used when the TDC-TEMPSTOR-METHOD parameter is set to V.

TDC-CICS-MSGDEST

input/output

Controls where the TDC directs status messages.

Default: CSSL

The valid range is any CICS-supported eight characters DDNAME.

TDC-REQID-PREFIX

input/output

2-byte REQID prefix (Start REQID) that supports any CICS-supported two characters. By default, the value is SQ.

TDC-TSQ-KEY-PREFIX

input/output

2-byte temporary storage prefix that supports any CICS-supported two characters. By default, the value is RQ.

Used when the TDC-TEMPSTOR-METHOD parameter is set to M or A.

TDC-SECURITY-MODE

input/output

Security mode for CA Gen transactions started by the TDC. Accepts the following values:

D—(default) CA Gen transactions inherit the user ID of the dispatcher transaction.

C—CA Gen transactions are started with the user ID supplied in the message. The user ID of the dispatcher must be an authorized surrogate for the message user ID. Clients must be using at least Advantage Gen 6.5 or later.

O—CA Gen transactions are started with the user ID supplied by the value in the TDC-OVERIDE-USERID parameter. The user ID of the dispatcher must be an authorized surrogate for the user ID supplied in the TDC-OVERIDE-USERID parameter.

Note: For more information about these modes, see the Distributed Processing – WebSphere MQ User Guide.

TDC-TEMPSTOR-METHOD

input/output

Sets the temporary storage method. Accepts the following values:

M—(default) Use CICS main temporary storage (TSQ).

A—Use auxiliary temporary storage method (TSQ).

V—Use VSAM file control (SDT recommended). If you set this parameter to V, you also need to set TDC-VSAM-DDNAME.

TDC-REPTOQM-SELECT

input/output

Use Client Specified (C) or Local (L) Manager for Reply to Queue.

Client Specified is the default.

TDC-TASK-TABLE-MAX

input/output

Maximum table occurence for started servers.

TDC-CHILD-MQGET-WAIT

input/output

Time to keep the child queue open.

TDC-RESERVED

input

Reserved for future use.

TDC-PROCESS-OBJ-UA

input

Copy of the 128-byte process definition user area associated with a queue and passed into the trigger record.

Not modifiable. The TDC cannot use this area, but the exit may read a value placed in the user area for input during an installation.