System events

A system event is a type of business event that results from system activity and contains system data. System events can include resource state changes, thresholds being crossed, or unusual system states or actions. Use system events to help you understand changes in the state of your system resources or system health.

Note:

CICS® TS 5.4 introduces support for system rules in CICS policies. Policy system rules provide equivalent or enhanced capability to system events and supersede system events. For more information, see Policy system rules.

Support for system events is deprecated; no further enhancements will be delivered in any future CICS releases. If you use system events, you can continue to do so in this release, and the following information provides details about the supported system events. However, support for system events might be withdrawn in a future release of CICS, so consider migrating to use policy system rules at the earliest opportunity.

You can be alerted to certain CICS system conditions by capturing events for those conditions. Receiving a notification for any changes to the state of system resources avoids the need to poll for changes after they happen; it also means that you can quickly respond to these system events.

Event processing supports the following system events:

DB2CONN connection status
FILE enable or disable status
FILE open or close status
MESSAGE
TASK threshold
TRANCLASS TASK threshold
Unhandled transaction abend

Capture points

The following table shows the capture points that are supported for system events.

Table 1. System event capture points
Capture point	Primary predicate	Filter Predicate Context	Filter Predicate Event Option	Capture Data Event Option	Description
DB2® CONNECTION STATUS	None	Transaction ID User ID	FROM_CONNECTST TO_CONNECTST	DB2ID DB2GROUPID DB2RELEASE FROM_CONNECTST TO_CONNECTST	You can capture an event whenever a DB2CONN connection status changes.¹
FILE ENABLE STATUS	FILE	Transaction ID User ID	FILE FROM_ENABLESTATUS TO_ENABLESTATUS OPENSTATUS	FILE DSNAME FROM_ENABLESTATUS TO_ENABLESTATUS OPENSTATUS	You can capture an event whenever a file ENABLESTATUS changes.¹
FILE OPEN STATUS	FILE	Transaction ID User ID	FILE FROM_OPENSTATUS TO_OPENSTATUS	FILE DSNAME FROM_OPENSTATUS TO_OPENSTATUS ENABLESTATUS	You can capture an event whenever a file OPENSTATUS changes.¹
MESSAGE	MESSAGE_ID	Transaction ID User ID	MESSAGE_ID INSERT1 to INSERT30 ²	MESSAGE_ID INSERT1 to INSERT30 MESSAGE_TEXT	You can capture an event whenever CICS emits a DFHxxnnnn ³ message or CICSPlex® SM emits a EYUxxnnnn message.
TASK THRESHOLD	None	None	PERCENT_MAXTASKS	FROM_TASKS TO_TASKS MAXTASKS PERCENT_MAXTASKS	You can capture an event whenever a task threshold is crossed. The threshold is chosen from a predefined list of 50%, 60%, 70%, 80%, 90, or 100%.
TRANCLASS TASK THRESHOLD	TRANCLASS	None	TRANCLASS PERCENT_MAXACTIVE	TRANCLASS FROM_ACTIVE TO_ACTIVE MAXACTIVE PERCENT_MAXACTIVE	You can capture an event whenever a TRANCLASS task threshold is crossed. The threshold is chosen from a predefined list of 50%, 60%, 70%, 80%, 90%, or 100%.
TRANSACTION ABEND (Unhandled)	TRANSACTION	User ID	TRANSACTION ABCODE	TRANSACTION ABCODE	You can capture an event whenever a transaction encounters any unhandled abend.

Notes:

The change can occur either through explicit operator actions, EXEC CICS SET commands, or implicitly as a result of CICS internal processing.
You can choose up to 10 message insert filters. Ensure that you use an available insert, because the CICS event binding editor does not prevent you from defining a filter on an unavailable insert and does not flag the error. Instead, the result is a runtime exception trace, the predicate evaluates as false, and no event is emitted. For example, message DFHFC0200 has 7 inserts. If you define a filter on INSERT 8 through 30, no event is emitted. Message inserts are shown in the individual message topics (see CICS messages).
You cannot event enable any of the following messages:
- Any CICS initialization messages issued before event processing starts. Event processing is started just before phase 2 initialization PLT programs are run.
- Any CICS termination messages issued after event processing stops. Event processing is stopped after all shutdown PLT programs have run.
- Any messages sent to a CICS user, for example, messages issued by CICS supplied transactions such as CEMT and CEDA.
- Any messages issued by the EC or EP components, that is, all DFHECnnnn and DFHEPnnnn messages.
A MESSAGE system event is emitted regardless of whether or not a message is suppressed by either an XMEOUT global user exit program or the system initialization parameter MSGLVL=0.
No transaction abend system events are emitted for any transaction abends originating in any task running an event processing adapter program.

For more information about the capture points you can select, see Capture Point tab in the CICS Explorer product documentation and Information Sources tab in the CICS Explorer product documentation.