Guards¶

Guards are labels that are produced by governance services when they complete and are used by the Open Governance Services to determine which step to run next in a governance action process.

For example, in the process below, the governance service called Get Day Of Week produces a guard that represents the current day of the week. This means that in its specification it lists 7 Produced Guard properties (monday, tuesday, wednesday, thursday, friday, saturday and sunday). Each of these possible guards are mapped to a step to run if that guard is produced. When the process runs, the first step runs and produces at least one guard. The steps linked to these guards are run.

It is possible that multiple guards can be mapped to the same step. In the example below there are two follow-on steps to Get Day Of Week. The Weekday Work is run if Get Day Of Week produces a guard of monday, tuesday, wednesday, thursday or friday. Weekend Work is run if the guard is saturday or sunday.

You may be wondering what would happen if Get Day Of Week produced multiple guards? By default, the open governance services will run an instance of the follow-on steps for each of the guards produced by Get Day of Week. So if Get Day Of Week returned the guards monday, monday, tuesday and saturday then Weekday Work would run 3 times and Weekend Work would run once.

It is possible to configure a step so it is only allowed to run once in the process instance. (See the ignoreMultipleTriggers property in the GovernanceActionProcessStep metadata element).

It is also possible that some guards are not mapped on a governance action process. This is not a problem. If an unmapped guard is produced during the execution of a governance action process, no follow-on step is run. So, in the example below, nothing happens if the saturday or sunday guard is produced. When there are no follow-on steps to run for a process, it terminates.

Finally, some guards may be flagged as mandatory guards (see NextGovernanceActionProcessStep relationship in model 0462). A step can not run until all linked mandatory guards have been produced. This allows the joining of parallel flows in the process.

Running the Daily Governance Action Process¶

Egeria includes a definition of the first governance action process shown on this page. It is part of the Core Content Pack and so is loaded automatically in the default and quickstart environment.

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