Fault Injection

Fault Injection configuration overview.


[config.filter.http.fault.v2.FaultAbort proto]

  "http_status": "...",
  "percentage": "{...}"
(uint32, REQUIRED) HTTP status code to use to abort the HTTP request.
(type.FractionalPercent) The percentage of requests/operations/connections that will be aborted with the error code provided.


[config.filter.http.fault.v2.HTTPFault proto]

  "delay": "{...}",
  "abort": "{...}",
  "upstream_cluster": "...",
  "headers": [],
  "downstream_nodes": [],
  "max_active_faults": "{...}",
  "response_rate_limit": "{...}"
(config.filter.fault.v2.FaultDelay) If specified, the filter will inject delays based on the values in the object.
(config.filter.http.fault.v2.FaultAbort) If specified, the filter will abort requests based on the values in the object. At least abort or delay must be specified.
(string) Specifies the name of the (destination) upstream cluster that the filter should match on. Fault injection will be restricted to requests bound to the specific upstream cluster.
(route.HeaderMatcher) Specifies a set of headers that the filter should match on. The fault injection filter can be applied selectively to requests that match a set of headers specified in the fault filter config. The chances of actual fault injection further depend on the value of the percentage field. The filter will check the request’s headers against all the specified headers in the filter config. A match will happen if all the headers in the config are present in the request with the same values (or based on presence if the value field is not in the config).
(string) Faults are injected for the specified list of downstream hosts. If this setting is not set, faults are injected for all downstream nodes. Downstream node name is taken from the HTTP x-envoy-downstream-service-node header and compared against downstream_nodes list.

(UInt32Value) The maximum number of faults that can be active at a single time via the configured fault filter. Note that because this setting can be overridden at the route level, it’s possible for the number of active faults to be greater than this value (if injected via a different route). If not specified, defaults to unlimited. This setting can be overridden via runtime <config_http_filters_fault_injection_runtime> and any faults that are not injected due to overflow will be indicated via the faults_overflow <config_http_filters_fault_injection_stats> stat.


Like other circuit breakers in Envoy, this is a fuzzy limit. It’s possible for the number of active faults to rise slightly above the configured amount due to the implementation details.


(config.filter.fault.v2.FaultRateLimit) The response rate limit to be applied to the response body of the stream. When configured, the percentage can be overridden by the fault.http.rate_limit.response_percent runtime key.


This is a per-stream limit versus a connection level limit. This means that concurrent streams will each get an independent limit.