Jobs

• github: Jobs

Motivation

• Import data periodically (SCADA, Supervisory Control and Data Acquisition)

• Export data periodically (e.g. to pass French certification for Air)

Principles

• Job is triggered by time events.

• Jobs are controlled by Schedulers.

• Jobs are executed per ApplicationWorkspaces.

• Time events are not kept in logs (PLog, WLog).

• Job support the following intents:

  • Views

  • SendMail

• Job state scope is almost the same as the Projector scope.

  • +JobContext

  • -Event

Functional design

VSQL:

ALTER WORKSPACE sys.AppWorkspaceWS (
    VIEW JobStateView(
        Fixed int,
        Data bytes,
        PRIMARY KEY ((Fixed))
    ) AS RESULT OF TestJob1;

	EXTENSION ENGINE BUILTIN (
		-- `CRON` token is not needed
		JOB Job1 '1 0 * * *' INTENTS(View(JobStateView));
	);
);

 ┌───────────── minute (0 - 59)
 │ ┌───────────── hour (0 - 23)
 │ │  ┌───────────── day of the month (1 - 31)
 │ │  │  ┌───────────── month (1 - 12)
 │ │  │  │  ┌───────────── day of the week (0 - 6) (Sunday to Saturday, 0 is Sunday)
 │ │  │  │  │
 1 0  *  *  *

• Only sys.AppWorkspaceWS is allowed for now

Tech design

• pkg/processors/schedulers/ProvideSchedulers(), similar to ProvideActualizers

• appparts

func New2(
	vvmCtx context.Context,
	structs istructs.IAppStructsProvider,
	syncAct SyncActualizerFactory,
	asyncActualizersRunner IProcessorRunner,
	jobSchedulerRunner IProcessorRunner, // <--------------- 
	eef iextengine.ExtensionEngineFactories,
) (ap IAppPartitions, cleanup func(), err error) {
	return newAppPartitions(vvmCtx, structs, syncAct, asyncActualizersRunner, jobSchedulerRunner, eef)
}

Context

• https://www.ibm.com/docs/en/db2oc?topic=task-unix-cron-format

• https://github.com/robfig/cron/blob/master/parser.go