Using the Enforced Timeout middleware with Tyk OAS APIs

Tyk’s enforced timeout middleware is configured at the endpoint level, where it sets a limit on the response time from the upstream service. If the upstream takes too long to respond to a request, Tyk will terminate the request and return 504 Gateway Timeout to the client.

When working with Tyk OAS APIs the enforced timeout is configured in the Tyk OAS API Definition. You can do this via the Tyk Dashboard API or in the API Designer.

If you’re using the legacy Tyk Classic APIs, then check out the Tyk Classic page.

Configuring an enforced timeout in the Tyk OAS API Definition

The design of the Tyk OAS API Definition takes advantage of the operationId defined in the OpenAPI Document that declares both the path and method for which the middleware should be added. Endpoint paths entries (and the associated operationId) can contain wildcards in the form of any string bracketed by curly braces, for example /status/{code}. These wildcards are so they are human readable and do not translate to variable names. Under the hood, a wildcard translates to the “match everything” regex of: (.*).

The circuit breaker middleware (enforceTimeout) can be added to the operations section of the Tyk OAS Extension (x-tyk-api-gateway) in your Tyk OAS API Definition for the appropriate operationId (as configured in the paths section of your OpenAPI Document).

The enforceTimeout object has the following configuration:

• enabled: enable the middleware for the endpoint
• value: the duration of the upstream request timer

For example:

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{
    "components": {},
    "info": {
        "title": "example-timeout",
        "version": "1.0.0"
    },
    "openapi": "3.0.3",
    "paths": {
        "/status/200": {
            "get": {
                "operationId": "status/200get",
                "responses": {
                    "200": {
                        "description": ""
                    }
                }
            }
        }
    },
    "x-tyk-api-gateway": {
        "info": {
            "name": "example-timeout",
            "state": {
                "active": true
            }
        },
        "upstream": {
            "url": "http://httpbin.org/"
        },
        "server": {
            "listenPath": {
                "value": "/example-timeout/",
                "strip": true
            }
        },
        "middleware": {
            "operations": {
                "status/200get": {
                    "enforceTimeout": {
                        "enabled": true,
                        "value": 3
                    }
                }
            }
        }
    }
}

In this example Tyk OAS API definition, the enforced timeout has been configured to monitor requests to the GET /status/200 endpoint. It will configure a timer that will expire (timeout) 3 seconds after the request is proxied to the upstream service. If the upstream response is not received before the expiry of the timer, that request will be terminated and Tyk will return 504 Gateway Timeout to the client.

The configuration above is a complete and valid Tyk OAS API Definition that you can import into Tyk to try out the enforced timeout.

Configuring an enforced timeout in the API Designer

Adding the enforced timeout to your API endpoints is easy when using the API Designer in the Tyk Dashboard, simply follow these steps:

Step 1: Add an endpoint

From the API Designer add an endpoint that matches the path and method to which you want to apply the middleware.

Step 2: Select the Enforce Timeout middleware

Select ADD MIDDLEWARE and choose the Enforce Timeout middleware from the Add Middleware screen.

Step 3: Configure the middleware

Set the timeout duration that you wish to enforce for requests to the endpoint.

Select ADD MIDDLEWARE to apply the change to the middleware configuration.

Step 4: Save the API

Select SAVE API to apply the changes to your API.