Configuring Timeouts

To limit how long Linkerd will wait before failing an outgoing request to another service, you can configure timeouts. These work by adding a little bit of extra information to the service profile for the service you’re sending requests to.

Note

Routes configured in service profiles are different from HTTPRoute resources. Service profile routes allow you to collect per-route metrics and configure client-side behavior such as retries and timeouts. HTTPRoute resources, on the other hand, can be the target of AuthorizationPolicies and allow you to specify per-route authorization.

Each route may define a timeout which specifies the maximum amount of time to wait for a response (including retries) to complete after the request is sent. If this timeout is reached, Linkerd will cancel the request, and return a 504 response. If unspecified, the default timeout is 10 seconds.

spec:
  routes:
  - condition:
      method: HEAD
      pathRegex: /authors/[^/]*\.json
    name: HEAD /authors/{id}.json
    timeout: 300ms

Check out the timeouts section of the books demo for a tutorial of how to configure timeouts.

Monitoring Timeouts

Requests which reach the timeout will be canceled, return a 504 Gateway Timeout response, and count as a failure for the purposes of effective success rate. Since the request was canceled before any actual response was received, a timeout will not count towards the actual request volume at all. This means that effective request rate can be higher than actual request rate when timeouts are configured. Furthermore, if a response is received just as the timeout is exceeded, it is possible for the request to be counted as an actual success but an effective failure. This can result in effective success rate being lower than actual success rate.