Semaphore circuit thread pool metrics regression

[mattnelson]

When upgrading from 1.5.3 to 1.5.5 semaphore circuits now contain a thread pool entry in the hystrix-metrics-event-stream. It looks like this is only a stream regression as I don't see a corresponding increase in the number of threads.

1.5.5 stream

data: {
  "type": "HystrixCommand",
  "name": "circuit155",
  "group": "circuit155",
  "rollingCountSemaphoreRejected": 0,
  "rollingCountThreadPoolRejected": 0,
  "propertyValue_executionIsolationStrategy": "SEMAPHORE",
  "propertyValue_executionIsolationThreadTimeoutInMilliseconds": 60000,
  "propertyValue_executionIsolationThreadInterruptOnTimeout": true,
  "propertyValue_executionIsolationThreadPoolKeyOverride": null,
  "propertyValue_executionIsolationSemaphoreMaxConcurrentRequests": 100,
  "propertyValue_fallbackIsolationSemaphoreMaxConcurrentRequests": 10,
  "threadPool": "circuit155"
}

data: {
  "type": "HystrixThreadPool",
  "name": "circuit155"
}

1.5.3 stream

data: {
  "type": "HystrixCommand",
  "name": "circuit153",
  "group": "circuit153",
  "rollingCountSemaphoreRejected": 0,
  "rollingCountThreadPoolRejected": 0,
  "propertyValue_executionIsolationStrategy": "SEMAPHORE",
  "propertyValue_executionIsolationThreadTimeoutInMilliseconds": 60000,
  "propertyValue_executionIsolationThreadInterruptOnTimeout": true,
  "propertyValue_executionIsolationThreadPoolKeyOverride": null,
  "propertyValue_executionIsolationSemaphoreMaxConcurrentRequests": 100,
  "propertyValue_fallbackIsolationSemaphoreMaxConcurrentRequests": 10,
  "threadPool": "circuit153"
}

[mattrjacobs]

Thanks for the report @mattnelson . I'll get this fixed in the 1.5.6 release. It's likely related to the refactoring I did to move metrics serialization to a single place.

[mattrjacobs]

Fixed in #1363