TRANCLASS attributes

Describes the syntax and attributes of the TRANCLASS resource.

The transaction class definition attribute descriptions are:

DESCRIPTION(text)

You can provide a description of the resource that you are defining in this field. The description text can be up to 58 characters in length. No restrictions apply to the characters that you can use. However, if you use parentheses, ensure that for each left parenthesis there is a matching right parenthesis. If you use the CREATE command, for each single apostrophe in the text, code two apostrophes.

GROUP(groupname)

Every resource definition must have a GROUP name. The resource definition becomes a member of the group and is installed in the CICS system when the group is installed.

Acceptable characters: `A-Z 0-9 $ @ #` Any lowercase characters that you enter are converted to uppercase.

The GROUP name can be up to 8 characters in length. Lowercase characters are treated as uppercase characters.

MAXACTIVE(number)

specifies the maximum number of transactions in this transaction class that are allowed to be active. You must specify a MAXACTIVE value when you define a transaction class, in the range 0 through 999.

New transactions attached when the number of active transactions has reached the MAXACTIVE limit are considered for queueing subject to the PURGETHRESH limit.

Defining a transaction class with a zero MAXACTIVE value signifies that all tasks are to be queued.

PURGETHRESH({NO|number})

This is an optional purge threshold for the transaction class; it defines a threshold number at which transactions queuing for membership of the transaction class are purged. Specify it if you want to limit the number of transactions queueing in this transaction class. It can have the following values:

NO: The size of the queue is unlimited (other than by the storage available to attach tasks).
number: The purge threshold number in the range 1—1 000 000.
If you specify this as 1, no transactions are allowed to queue. If you specify it as any other number (n), the size of the queue is restricted to number-1. All new transactions attached after the limit of n-1 is reached are purged.

Example of PURGETHRESH: In the case of a transaction class where the maximum number of active tasks (MAXACTIVE) is set to 50, and the purge threshold (PURGETHRESH) is set to 10 to limit queuing transactions, CICS® begins to abend new transactions for the class when:

The number of active transactions reaches 50, and
The number of transactions queuing for membership of the transaction class has reached 9

CICS accepts new transactions for this transaction class queue only when the number queued falls below the maximum size of the queue (9 in our example).

TRANCLASS(name)

specifies the name of the transaction class. Transactions belonging to a transaction class are subject to scheduling constraints before they are allowed to execute. The reserved TRANCLASS name DFHTCL00 is used to indicate that the transaction does not belong to any transaction class.

For compatibility with releases that support a TCLASS attribute, CICS provides the following TRANCLASS equivalents:

TCLASS TRANCLASS

 NO          DFHTCL00
 1           DFHTCL01
 2           DFHTCL02
 3           DFHTCL03
 4           DFHTCL04
 5           DFHTCL05
 6           DFHTCL06
 7           DFHTCL07
 8           DFHTCL08
 9           DFHTCL09
 10          DFHTCL10

Sample definitions for these transaction classes are in group DFHTCL, supplied as part of DFHLIST.

Note: If a transaction is run and its associated TRANCLASS definition is not installed, the transaction runs without any of the scheduling constraints specified in the TRANCLASS. Attention message DFHXM0212 is issued.

TRANCLASS can be up to eight characters in length.

Acceptable characters: `A-Z 0-9 $ @ #` Unless you are using the CREATE command, any lowercase characters that you enter are converted to uppercase.