Timeouts

Emissary enables you to control timeouts in several different ways.

Request timeout: timeout_ms

timeout_ms is the end-to-end timeout for an entire user-level transaction in milliseconds. It begins after the full incoming request is received up until the full response stream is returned to the client. This timeout includes all retries. It can be disabled by setting the value to 0.

Default: 3000

Idle timeout: idle_timeout_ms

idle_timeout_ms controls how long a connection should remain open when no traffic is being sent through the connection. idle_timeout_ms is distinct from timeout_ms, as the idle timeout applies on either down or upstream request events and is reset every time an encode/decode event occurrs or data is processed for the stream. idle_timeout_ms operates on a per-route basis and will overwrite behavior of the cluster_idle_timeout_ms. If not set, Emissary will default to the value set by cluster_idle_timeout_ms. It can be disabled by setting the value to 0.

Cluster max connection lifetime: cluster_max_connection_lifetime_ms

cluster_max_connection_lifetime_ms controls how long upstream connections should remain open, regardless of whether traffic is currently being sent through it or not. By setting this value, you can control how long Envoy will hold open healthy connections to upstream services before it is forced to recreate them, providing natural connection churn. This helps in situations where the upstream cluster is represented by a service discovery mechanism that requires new connections in order to discover new backends. In particular, this helps with Kubernetes Service-based routing where the set of upstream Endpoints changes, either naturally due to pod scale up or explicitly because the label selector changed.

Cluster idle timeout: cluster_idle_timeout_ms

cluster_idle_timeout_ms controls how long a connection stream will remain open if there are no active requests. This timeout operates based on outgoing requests to upstream services. It can be disabled by setting the value to 0.

Default 3600000 (1 hour).

Connect timeout: connect_timeout_ms

connect_timeout_ms sets the connection-level timeout for Emissary to an upstream service at the network layer. This timeout runs until Emissary can verify that a TCP connection has been established, including the TLS handshake. This timeout cannot be disabled.

Default: 3000

Module only

Listener idle timeout: listener_idle_timeout_ms

listener_idle_timeout_ms configures the idle_timeout in the Envoy HTTP Connection Manager and controls how long a connection from the downstream client to Emissary will remain open if there are no active requests. Only full requests will be counted towards this timeout so clients sending TCP keepalives will not guarantee a connection remains open. This timeout It can be disabled by setting the value to 0.

Default: 3600000 (1 hour)

Caution Disabling this timeout increases the likelihood of stream leaks due to missed FINs in the TCP connection.

Example

The various timeouts are applied to a Mapping resource and can be combined.

---
apiVersion: getambassador.io/v3alpha1
kind:  Mapping
metadata:
  name:  quote-backend
spec:
  hostname: '*'
  prefix: /backend/
  service: quote
  timeout_ms: 4000
  idle_timeout_ms: 500000
  connect_timeout_ms: 2000