Infinite loop in Apache Camel

Question

I need to create a route, which periodically calls some process with a small delay between iterations.

When I look at documentation for looping:

The Loop allows for processing a message a number of times, possibly in a different way for each iteration. Useful mostly during testing.

So this is not useful for me, since I need to do an infinite loop (without the CamelLoopSize explicitly specified).

My second idea was using kind of a "recursion":

from("direct:updateLoop").routeId("updateLoop")
  .process(someProcess)
  ...
  .filter(someFilter)  // Can be used to stop the workflow
  .delay(18000000)  // Wait 5 hours and start again
  .to("direct:updateLoop")

This works well for a few days, however after about 600 iterations, this fails with StackOverflowException

Is there a better way to run my process in an infinite loop?

Because I cannot determine in advance how long it will take the process to be finished. The process can take few minutes or few days to be done. When I set up just a timer, there will be a possibility of concurrent processing of the same data set. Setting-up a delay simply fits better for my use case. — Peter, Oct 09 '14 at 08:38

score 4 · Accepted Answer · edited May 23 '17 at 10:29

4

Use Camel Timer component:

from("timer://foo?fixedRate=false&period=18000000")
     .process(someProcess);

If fixedRate is false, then no overlapping will occur, see Apache Camel timer: "period" vs "fixedRate"

edited May 23 '17 at 10:29

Community

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answered Oct 09 '14 at 09:20

Peter Keller

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score 2 · Answer 2 · answered Apr 14 '16 at 08:09

2

For recursion you can use camel's seda component.

from("seda:updateLoop").routeId("updateLoop")
    .process(someProcess)
    ...
    .filter(someFilter)  // Can be used to stop the workflow
    .delay(18000000)  // Wait 5 hours and start again
    .to("seda:updateLoop");

answered Apr 14 '16 at 08:09

Ben Keil

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I have upvoted because it is solution for really long processing - I mean I had many data, which were transported using camel from destination A to destination B, until there is something in A.. That caused stackoverflow, just because the stack was too long (without recursion!) – Cipous Jun 10 '16 at 09:49

Infinite loop in Apache Camel

2 Answers2