Additional metric `hystrix_thread_pool_property_value_maximum_size`

• Update Prometheus simpleclient to v0.10.0
• Additional metric hystrix_thread_pool_property_value_maximum_size (thanks to @victormferrara) (#29)
• Fixing typo in metric description error_total (thanks to @dadadom) (#23)

Drop deprecated metrics from 3.4, rework event counting

• Removing all deprecated metrics from 3.x release. This is a breaking change. Therefore bump to next major release.
• Add additional label terminal to all metrics of name hystrix_command_event_total.
  Use this to identify if the event is a terminal event. #19
• Marking hystrix_command_total as deprecated.
  Instead you should you should sum up all hystrix_command_event_total with state "terminal" set to "true". #19
• Marking hystrix_command_error_total as deprecated.
  Instead you should you should sum up all hystrix_command_event_total with state "terminal" set to "true"
  that you consider errors in your scenarios. #19

JDK6/7 support and advanced options about registering as a a Hystrix Plugin

• support JDK6 and JDK7 as both are still supported by Prometheus and Hystrix as well #16
• deterministic sorting of prometheus labels (to ease testing) #16
• don't automatically register default plugins #14

Fixing Histograms for non-executed commands

• non-executed commands (i.e. due to active circuit breakers) should not update histograms (#12)

Optimizing Histograms

• Command Histograms can now be configured, and the buckets are now the default library buckets as provided by Hystrix (.005, .01, .025, .05, .075, .1, .25, .5, .75, 1, 2.5, 5, 7.5, 10) (#9)
• The publisher can now be configured using a builder pattern using HystrixPrometheusMetricsPublisher.builder()/* ... */.buildAndRegister()
• Rename rolling_max_active_threads to rolling_active_threads_max, rolling_count_threads_executed to rate(threads_executed_total), count_threads_executed to threads_executed_total.

Histograms and Co-Existence

• Aiming to publish the command metrics Prometheus style (#4):

  • histograms hystrix_command_event_total and hystrix_command_latency_total replace existing gauges hystrix_command_latency_execute_percentile_XXX and hystrix_command_latency_execute_XXX.
  • counters hystrix_command_total and hystrix_command_error_total to replace the hystrix_command_error_percentage gauge.
  • hystrix_command_event_total contains per event counters with the event type as a label to replace hystrix_command_count_XXX.

• Co-exist with other Hystrix plugins like Spring Sleuth (#5)

Maven Central

• Migrating from Gradle to Maven to have it in line with Prometheus Simple Client.
• First release to Maven Central.