@Aggregates({EventSource.SAFEPOINT}) will fall into dead loop

[ZhangShushu123]

When I create an Aggregator with @Aggregates({EventSource.SAFEPOINT}). The program will loop forever.
I read the source code and I found that there is no LogFileParser with the outbox SAFEPOINT .
Therefore, when the program execute the code aggregatorVerticles.forEach(AggregatorVerticle::awaitCompletion); , the Aggregator with @Aggregates({EventSource.SAFEPOINT}) will not complete forever.

[ZhangShushu123]

Is GCToolkitVertxParametersForPreUnifiedLogs.java line 140 AggregatorVerticle aggregatorVerticle = new AggregatorVerticle(SAFEPOINT_OUTBOX); change to AggregatorVerticle aggregatorVerticle = new AggregatorVerticle(GCToolkitVertx.JVM_EVENT_PARSER_OUTBOX);?
Because there is no AggregatorVerticle with the inbox JVM_EVENT.
However, I think we should add an EventSource enum value of JVM_EVENT will be better than the before one.

[dsgrieve]

Nice find!

I think the issue here is that the SafePointParser is never created. I think part of the fix is to add this block of code to the initLogFileParsers method of GCToolkitVertxParametersForPreUnifiedLogs.

        if (diary.isApplicationStoppedTime() || diary.isApplicationRunningTime()) {
            logFileParsers.add(new LogFileParser(GCToolkitVertx.PARSER_INBOX, SAFEPOINT_OUTBOX, consumer -> new SafepointParser(diary, consumer)));
        }

The if (diary.isApplicationStoppedTime() || diary.isApplicationRunningTime()) test is probably needed around the code that calls getAggregators(EventSource.SAFEPOINT, registeredAggregations) down in initAggregatorVerticles in the same class.

It would be awesome, @ZhangShushu123, if you could work this issue!

[ZhangShushu123]

By the way, I think adding code to remove aggregatorVerticles which inbox can not match with the logFileParser in aggregateDataSource() is a best way to prevent the dead loop. Moreover, logging the removed aggregatorVerticle in console with error level will tell us which aggregatorVerticle can not match and we should fix in the future.

[ZhangShushu123]

The code which should be added in aggregateDataSource() will show below. Of course, the code can be written more gracefully.

 aggregatorVerticles.removeIf(aggregatorVerticle -> {
      boolean isMatch = logFileParsers.stream().anyMatch(logFileParser -> logFileParser.getOutbox() == aggregatorVerticle.getInbox());
      if(!isMatch){
            LOGGER.log(Level.SEVERE, String.format("%s %s",aggregatorVerticle.getInbox(),aggregatorVerticle));
      }
      return !isMatch;
});

[dsgrieve]

@ZhangShushu123 - would you be willing to create a PR for these changes?

[ZhangShushu123]

Of course. I will make a pull request as soon as possible.