HTTPRoute Timeouts

[mpstefan]

As a user of NGF
I want to specify timeouts per request for my HTTPRoutes
So that my client applications can get quick feedback that the request will not complete

Background:

NGINX provides the following directives for timeouts:

• proxy_connect_timeout
• proxy_read_timeout
• proxy_send_timeout
• proxy_next_upstream_timeout

All of these timeouts are based on packet transfer to the upstream instead of the individual requests. As such, we will need to create an NJS module to support a "true" HTTP timeout that will time out individual requests based on the request itself instead of measuring when a packet was last received from the upstream for any request.

This feature is defined in the Gateway API here as an extended feature.

Acceptance

• The user can define a "request" duration for a timeout in an HTTPRoute rule and functions as defined here:

  Request specifies the maximum duration for a gateway to respond to an HTTP request. If the gateway has not been able to respond before this deadline is met, the gateway MUST return a timeout error.

  For example, setting the rules.timeouts.request field to the value 10s in an HTTPRoute will cause a timeout if a client request is taking longer than 10 seconds to complete.

  Setting a timeout to the zero duration (e.g. “0s”) SHOULD disable the timeout completely. Implementations that cannot completely disable the timeout MUST instead interpret the zero duration as the longest possible value to which the timeout can be set.

  This timeout is intended to cover as close to the whole request-response transaction as possible although an implementation MAY choose to start the timeout after the entire request stream has been received instead of immediately after the transaction is initiated by the client.

  The value of Request is a Gateway API Duration string as defined by GEP-2257. When this field is unspecified, request timeout behavior is implementation-specific.

• The user can define a "backendRequest" duration for a timeout in an HTTPRoute rule and functions as defined here:

  BackendRequest specifies a timeout for an individual request from the gateway to a backend. This covers the time from when the request first starts being sent from the gateway to when the full response has been received from the backend.

  Setting a timeout to the zero duration (e.g. “0s”) SHOULD disable the timeout completely. Implementations that cannot completely disable the timeout MUST instead interpret the zero duration as the longest possible value to which the timeout can be set.

  An entire client HTTP transaction with a gateway, covered by the Request timeout, may result in more than one call from the gateway to the destination backend, for example, if automatic retries are supported.

  The value of BackendRequest must be a Gateway API Duration string as defined by GEP-2257. When this field is unspecified, its behavior is implementation-specific; when specified, the value of BackendRequest must be no more than the value of the Request timeout (since the Request timeout encompasses the BackendRequest timeout).

[chrisakker]

None of these timeouts are packet based. They are all TCP connections, or HTTP request/response timeouts, and LB selection timeouts. For further review, read the actual text of the Directives that you linked to. There is no need for NJS, Nginx core does this by default.