Poller
Global poller that specifies when and how scheduled message receive tasks should be executed.
All the endpoints that have to do a scheduled task like receiving on a queue channel or reading files, need a poller that specifies when and how the task is executed. The scheduled task is executed by the Task Executor if specified. Else the default task executor will be used.
If no poller is specified for an endpoint, the default global poller is used. Currently a global poller can only be used as a default poller. There can only be one default poller in a configuration.
Default
Set this poller as default poller of the configuration. If set, this poller will be used by all the endpoints that have no poller specified.
Note: Only one poller can be default in a configuration.
Id
Name that uniquely identifies this flow component.
Required
Max messages per poll
Specifies the maximum number of messages to receive within a given poll operation.
The poller will continue trying to receive without waiting until either no message is available or this maximum is reached.
For example, if a poller has a 10 second interval trigger and a maxMessagesPerPoll setting of 25, and it is polling a channel that has 100 messages in its queue, all 100 messages can be retrieved within 40 seconds. It grabs 25, waits 10 seconds, grabs the next 25, and so on.
Default is 1.
Receive timeout
Specifies the amount of time the poller should wait if no messages are available when receiving.
Send timeout
Specifies the timeout for sending out messages.
Task executor
Task executor to execute the scheduled tasks.
Default when empty: TaskScheduler with name 'taskScheduler', created if not exists.
Error channel
The channel that error messages will be sent to if a failure occurs in this poller's invocation. To completely suppress exceptions, provide a reference to the nullChannel here.
Trigger type
A trigger specifies the schedule of the poller.
Trigger types:
1. Fixed delay trigger Triggers with a periodic constant interval. Each execution is scheduled relative to the actual execution time of the previous execution. If an execution is delayed for any reason (such as garbage collection or other background activity), subsequent executions will be delayed as well.
2. Fixed rate trigger Triggers with a periodic constant interval. Each execution is scheduled relative to the scheduled execution time of the initial execution.If an execution is delayed for any reason , two or more executions will occur in rapid succession to "catch up."
3. Cron trigger Enables the scheduling of tasks based on cron expressions. Consider using a cron trigger for hourly, daily, and monthly settings.
Time unit
Specifies the time unit of the fixed delay or fixed rate value.
For hourly, daily or monthly settings, consider using a cron trigger instead.
Default is Milliseconds
.
Fixed delay
Time between each two subsequent executions, measured from completion time.
Fixed rate
Time between each two subsequent executions, measured from start time.
Cron
Pattern used by a cron-trigger to specify the trigger schedule.
The pattern is a list of six single space-separated fields, representing second minute hour day month weekday
. Month and weekday names can be given as the first three letters of the English names.
Example patterns:
0 0 * * * *
= the top of every hour of every day
0 0 8-10 * * *
= 8, 9 and 10 o'clock of every day
0 0/30 8-10 * * *
= 8:00, 8:30, 9:00, 9:30 and 10 o'clock every day
0 0 9-17 * * MON-FRI
= on the hour nine-to-five weekdays
0 0 0 25 12 ?
= every Christmas Day at midnight