End of Sale Notice:

F5 NGINX is announcing the End of Sale (EoS) for NGINX Management Suite API Connectivity Manager Module, effective January 1, 2024.

F5 maintains generous lifecycle policies that allow customers to continue support and receive product updates. Existing API Connectivity Manager Module customers can continue to use the product past the EoS date. License renewals are not available after September 30, 2024.

See our End of Sale announcement for more details.

Proxy Cache

Learn how to use F5 NGINX Management Suite API Connectivity Manager to enable and configure caching to improve the performance of your API gateway proxy.

Overview

In API Connectivity Manager, you can apply policies to an API Gateway to further enhance their configuration to meet your requirements.

Policies added at the proxy level are applied to all routes within that proxy.

For an overview of the different policy types and available policies, refer to the consult the Learn about Policies topic.

About the Policy

Enable and configure caching to improve the performance of your API Gateways, speed up delivery to clients, and reduce the load on the backend API runtimes. When caching is enabled, the API Gateway saves responses to a disk cache and uses them to respond to clients without having to proxy requests for the same content every time.

By default, the API Gateway caches all responses to requests made with the HTTP GET and HEAD methods the first time such responses are received from a proxied server. The API Gateway uses the request string as a request’s key (identifier). If a request has the same key as a cached response, the API Gateway sends the cached response to the client. You can customize and control which responses are cached.

Fine-tune the cache for further improvements in performance by instructing it to use conditional GET requests when refreshing content from origin servers, set a minimum request number to cache content, enable background update, and cache lock.

Intended Audience

This guide is intended for API Owners — the individuals or teams who are responsible for designing, creating, and maintaining APIs.

How to apply the policy

  • Create an API proxy or edit an existing one.
  • Check the advanced settings for the API proxy to see if the policy has been applied.
  • Edit the policy to make changes for each API proxy. Save and publish the changes.

Policy Settings

The following table lists the configurable settings and their default values for the policy.

Field Datatype Possible Values Description Required Default
httpMethods array GET, HEAD, POST HTTP request methods to cache. No GET, HEAD
cacheKey array host, requestURI, scheme, cookieJSessionID, cookieUser Keys to be cached. ‘host’ is the name & port of the proxied server. ‘requestURI’ is the URI of the request. ‘scheme’ is the protocol used to access the resource on the proxied server. ‘cookieJSessionID’ is the cookie used for session management. ‘cookieUser’ is the cookie used for user management. No host, requestURI, scheme
maxCacheSize string 1K (available units - K, M, G) Upper limit of the size of the cache. No 1G
cacheValidTime string 1s (available units - s, m, h) Enforces an expiration for the cached data. No 10m
minUseOfProxyToCache integer 1 Minimum number of client requests before caching is enabled. No 1
reValidate boolean true/false Enables revalidation of expired cache items using conditional GET requests with the If-Modified-Since and If-None-Match header fields. No false
backgroundUpdate boolean true/false Enables delivery of stale content when clients request an item that is in the process of being updated from the origin server. All updates will be done in the background. The stale file is returned for all requests until the updated file is fully downloaded. No false
stale.backendErrors array error, timeout, invalid_header, updating Determines in which cases a stale cached response can be used during communication with the proxied server. No
stale.backendCodes array 403, 404, 429, 500, 502, 503, 504 Determines for which HTTP status codes a stale cached response can be used during communication with the proxied server. No
cacheLock.enabled boolean true/false When enabled, only one request at a time will be allowed to populate a new cache element identified according to the cacheKey by passing a request to a proxied server. No false
cacheLock.age string 1s (available units - s, m, h) If the last request passed to the proxied server for populating a new cache element has not completed for the specified time, one more request may be passed to the proxied server. No 5s
cacheLock.timeout string 1s (available units - s, m, h) Sets a timeout for cacheLock; When the time expires, the request will be passed to the proxied server, however, the response will not be cached. No 5s

Adding the Policy

See Also:

You can use tools such as curl or Postman to interact with the API Connectivity Manager REST API. The API URL follows the format https://<NMS_FQDN>/api/acm/<API_VERSION> and must include authentication information with each call. For more information about authentication options, please refer to the API Overview.

To apply the Proxy Cache policy using the REST API, send an HTTP POST request to the Proxies endpoint.

Method Endpoint
POST /services/workspaces/{workspaceName}/proxies
JSON request 
{
    "policies": {
        "proxy-cache": [
            {
                "action": {
                    "httpMethods": [
                        "GET",
                        "HEAD",
                        "POST"
                    ],
                    "cacheKey": [
                        "host",
                        "requestURI",
                        "scheme",
                        "cookieJSessionID",
                        "cookieUser"
                    ],
                    "maxCacheSize": "1G",
                    "cacheValidTime": "10m",
                    "minUseOfProxyToCache": 1,
                    "reValidate": true,
                    "backgroundUpdate": true,
                    "stale": {
                        "backendErrors": [
                            "error",
                            "timeout",
                            "invalid_header",
                            "updating"
                        ],
                        "backendErrorCodes": [
                            403,
                            404,
                            429,
                            500,
                            502,
                            503,
                            504
                        ]
                    },
                    "cacheLock": {
                        "enabled": true,
                        "age": "5s",
                        "timeout": "5s"
                    }
                }
            }
        ]
    }
}

To apply the Proxy Cache policy using the web interface:

  1. In a web browser, go to the FQDN for your F5 NGINX Management Suite host and log in. Then, from the Launchpad menu, select API Connectivity Manager.
  2. On the left menu, select Services.
  3. Select a workspace in the list that contains the API Proxy you want to update.
  4. On the workspace overview page, on the API Proxies tab, locate the API Proxy you want to update. Select the Actions menu (represented by an ellipsis, ...), then select Edit Proxy.
  5. On the left menu, select API Proxy > Advanced > Policies.
  6. On the Advanced > Policies page, on the API Proxy tab, locate Proxy Cache. Select the Actions menu (represented by an ellipsis, ...), then select Add Policy.
  7. Modify the configuration as needed.
  8. Select Add to apply the policy to the API Proxy.
  9. Select Save and Publish to deploy the configuration to the API Proxy.