
>>-TRANCLASS(name)--GROUP(groupname)--+-------------------+----->
'-DESCRIPTION(text)-'
.-PURGETHRESH(NO)-----.
>--MAXACTIVE(number)--+---------------------+------------------><
'-PURGETHRESH(number)-'
The transaction class definition attribute descriptions are:
- DESCRIPTION(text)
- You can provide a description of the resource you are defining in this
field. The description text can be up to 58 characters in length. There are
no restrictions on the characters that you can use. However,
if you use parentheses, ensure that for each left parenthesis there is a matching
right one. 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
lower case characters you enter are converted to upper case. |
The GROUP name can be up to eight characters in length. Lowercase
characters are treated as uppercase characters. Do not use group names beginning
with DFH, because these characters are reserved for use by CICS.
- 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 you enter are converted
to uppercase. |