diff --git a/docs/root/operations/admin.rst b/docs/root/operations/admin.rst index 4b967c5fe..d03b899a1 100644 --- a/docs/root/operations/admin.rst +++ b/docs/root/operations/admin.rst @@ -174,3 +174,21 @@ 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 :ref:`event stream` to hystrix dashboard. + + The dashboard should set the stream source to this admin endpoint. + +Note on usage of Hystrix dashboard to visualize Envoy statistics: + Detalied description on Hystrix and its dashboard can be found :ref:\here`. 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 availbale. + * Window size is set to 10sec, with 10 buckets of 1sec each. Currently, the value is not configurable. + +