Scheduler node

By adding a Scheduler node to a message flow, you can configure the message flow to run at regular intervals.

This topic contains the following sections:

Purpose

By using the Scheduler node, you can configure a message flow to run at specified intervals of time, or at specified times on specified days.

Using this node in a message flow

The Scheduler node is contained in the Timer drawer of the palette, and is represented in the IBM® App Connect Enterprise Toolkit by the following icon:

Scheduler node icon

When you use the Scheduler node in a message flow, you must add it as the first node in the flow because it is used to trigger when the flow runs.

The Scheduler node has two different modes of operation that you can choose by selecting the appropriate options in the Basic tab. The available modes of operation are Repeat interval and Calendar.

For more information about configuring the Scheduler node, see Configuring the Scheduler node.

Terminals and properties

The Scheduler node terminals are described in the following table.

Terminal	Description
Failure	The output terminal to which a message is routed if an error occurs before a message is propagated to the Out terminal.
Out	The output terminal to which messages are propagated when the interval expires. The content of the propagated message is defined by using the Output Message tab.
Catch	The output terminal to which the message is routed if an exception is thrown downstream and caught by this node. Exceptions are caught only if this terminal is attached.

The following tables describe the node properties that you can set on a specified tab. The column headed M indicates whether the property is mandatory (marked in the IBM App Connect Enterprise Toolkit with an asterisk if you must enter a value when no default is defined). The column headed C indicates whether the property is configurable (you can change the value when you add the message flow to the BAR file to deploy it).

Description properties:

Property	M	C	Default Value	Description
Node Name	Yes	No	The node type, Scheduler	The name of the node.
Short Description	No	No	None	A brief description of the node.
Long Description	No	No	None	Text that describes the purpose of the node in the message flow.

Basic properties:

Property	M	C	Default	Description
Schedule identifier	No	Yes	None	In Scheduler mode of operation, a user-supplied value that is written into the local environment to enable the origin of a downstream message to be identified.
Schedule control	Yes	No	None	Choice of radio buttons to select the mode of operation: Repeat interval or Calendar.
Repeat interval / Interval	No	Yes	1	In conjunction with the Unit value, defines the frequency at which messages are propagated.
Repeat interval / unit	No	Yes	Minutes	Select units from the menu (Hours, Minutes, or Seconds).
Repeat interval / Days	No	Yes	All days selected	Select or deselect check boxes for the required days.
Calendar mode	No	Yes	00 * * * *	A cron expression that defines when messages are propagated. The menus for Calendar mode compile to an expression that conforms to a subset of the cron specification. If you apply BAR overrides, you must enter this expression manually. Five levels of granularity are available, based on the largest time unit for the schedule: Every hour: "<minute> * * * " Every day: "<minute> <hour> * " Every week: "<minute> <hour> * <MON\|TUE\|WED\|THU\|FRI\|SAT\|SUN>" Every month: "<minute> <hour> <day of month> * " Every year: "<minute> <hour> <day of month><JAN\|FEB\|MAR\|APR\|MAY\|JUN\|JUL\|AUG\|SEP\|OCT\|NOV\|DEC> " The default value is: "00 * * * *", which equates to every hour at the 0th minute.
Time zone	Yes	Yes	UTC	Drop down menu to select the time zone. For example, UTC.
Run when flow is first switched on	No	Yes	Deselected	Select or deselect checkbox.

Output message properties:

Property	M	C	Default	Description
Message output control	Yes	No	Scheduler format	Controls which message format is propagated to the flow. The options are: Scheduler format Timeout notification node format Message Assembly file `Message Assembly file`. Type in the full path name for a file, or click Browse to either select a Message Assembly file from your local file system, or click the link to create a new Message Assembly file.

Instances properties:

Property	M	C	Default	Description
Additional instances pool	No	Yes	Use Pool Associated with Message Flow	The pool from which additional instances are obtained. If you select Use Pool Associated with Message Flow, additional instances are obtained from the message flow value. If you select Use Pool Associated with Node, additional instances are allocated from the additional instances of the node, based on the number specified in the Additional instances property.
Additional instances	No	Yes	0	The number of additional instances that the node can start when the Additional instances pool property is set to Use Pool Associated with Node. By default, no additional instances are given to the node.

Retry properties:

Property	M	C	Default	Description
Retry mechanism	Yes	No	Failure	How the node handles a flow failure. Valid options are: Failure Short retry Short and long retry
Retry threshold	Yes	Yes	0	The number of times to try the flow transaction again when the Retry mechanism property value is Short retry or Short and long retry.
Short retry interval	No	Yes	0	The interval, in seconds, between each retry if Retry threshold property is not zero.
Long retry interval	No	Yes	300	The interval between retries, if Retry mechanism property is Short and long retry and the retry threshold has been exhausted.

Monitoring

Property	M	C	Default	Description
Events	No	No	None	Events that you define for the node are displayed on this tab. By default, no monitoring events are defined on any node in a message flow. Use Add, Edit, and Delete to create, change, or delete monitoring events for the node; see Configuring monitoring event sources by using monitoring properties for details. You can enable and disable events that are shown here by selecting or clearing the Enabled checkbox .