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This article introduces how to achieve timing scheduling in storm applications, the content is very detailed, interested friends can refer to, I hope it can be helpful to you.

Real-time timing scheduling in storm is a better way to use spout's nextTuple () to trigger your scheduled tasks in a continuous loop.

First, the logic that needs to be scheduled is implemented with a bolt, and the pseudo code of the execute method is as follows:

/ / get the last scheduling time from the global object backtype.storm.Config of topology Date Last scheduling time = config.get ("Last scheduling time"); if (if current time-Last scheduling time > = scheduling interval) {/ / execute specific business logic doTask () / / save the execution time to the global object backtype.storm.Config config.put ("Last scheduled time", current time);}

Then, define a special spout that sends messages on a regular basis, such as the following sending a message every 8 seconds:

@ Override public void nextTuple () {try {Thread.sleep (8 * 1000); collector.emit (new Values ("Let's go!"));} catch (Exception e) {log.error (", e);}}

The message from this spout doesn't make any business sense, just to trigger the bolt above.

Add that if the above code throws the exception "storm Async loop died!" when executing config.put (), it saves the last execution time in redis instead.

On how to achieve timing scheduling in storm applications to share here, I hope that the above content can be of some help to you, can learn more knowledge. If you think the article is good, you can share it for more people to see.

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