diff --git a/docs/root/operations/admin.rst b/docs/root/operations/admin.rst old mode 100644 new mode 100755 index 71ab5345a..dce59f855 --- a/docs/root/operations/admin.rst +++ b/docs/root/operations/admin.rst @@ -174,3 +174,28 @@ The fields are: .. http:get:: /runtime?format=json Outputs /runtime in JSON format. This can be used for programmatic access of runtime values. + +.. http:get:: /hystrix_event_stream + + Start streaming + `event stream `_ + to Hystrix dashboard. Detalied description of Hystrix and its dashboard can be found + `here `_. + + The dashboard should set the stream source to this admin endpoint. + + Notes on the usage of Hystrix dashboard to visualize Envoy statistics: + Not all the data presented in the Hystrix dashboard is relevant in Envoy. + + * Success, Failure, Timeout, Error rate, Number of host, are shown in the dashboard. + * Hystrix's *Short circuit* is similar to Envoy's outlier detection, in that it is triggered by + error responses. In Envoy the result of high error rate is the host being ejected from the load + balancer pool, but it does not cause rejected requests, and therefore we set *Short circuited* + to 0, and circuit breaker is set to *Forced Closed*. + * *Bad request* does not exist in Envoy, and therefore is set to 0. + * Requests rejected as a result of exceeding max number of connections or queue size (in Envoy, + referred as *short circuited*) are presented as *Rejected*, which better suits Hystrix's + terminology. + * Latency information is currently not available. + * Window size is set to 10 seconds, with 10 buckets of 1 second each. Currently, the value is + not configurable.