CODEWITHSUNDEEP
javamultithreadingvert.x
AlasPoorYorick
AlasPoorYorick

Reputation: 57

Vertx blocked thread exception during executeBlocking

I have the following code:

vertx.executeBlocking( future -> {
    // do something that takes more than 60 seconds
    future.complete();
}, result -> {
    // handle the result
});

If the code inside executeBlocking takes more than 60 seconds to evaluate, then the BlockedThreadChecker starts printing exceptions in the logs about blocking the main event thread. In situations where I don't use executeBlocking, the warnings - as expected - are printed after only 2 seconds.

I know there are ways of disabling the BlockedThreadChecker log messages entirely, but I want to keep them as I would like to be notified if I do block the event thread.

Is my code inside executeBlocking actually blocking the main event thread? If it is, then now do I execute long-running tasks without blocking it? If it's not, then why are these messages being logged and how do I disable them (without disabling BlockedThreadChecker entirely?

Many thanks.

Upvotes: 3

Views: 3008

Answers (1)

tsegismont
tsegismont

Reputation: 9128

You haven't included your logs but I suspect they indicate the blocked thread is a worker thread.

The blocked thread checker, by default, warns you if an event loop is blocked for more than 2 seconds and, a worker, more than 60 seconds.

This is configurable in VertxOptions, with maxEventLoopExecuteTime and maxWorkerExecuteTime.

VertxOptions vertxOptions = new VertxOptions()
  .setMaxEventLoopExecuteTime(maxEventLoopExecuteTime)
  .setMaxWorkerExecuteTime(maxWorkerExecuteTime);

Note that both values must be expressed in nanoseconds.

Upvotes: 6

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