Move async use-cases and blog links to the async reference page

Move the use-cases and blog references from the queue-worker page to the
async reference page where they are more relevant. This keeps the
queue-worker page focused on queue-worker configuration rather than
general async use-cases.

Signed-off-by: Han Verstraete (OpenFaaS Ltd) <han@openfaas.com>

Author: welteki

docs/openfaas-pro/jetstream.md

@@ -12,24 +12,13 @@ This page is primarily concerned with how to configure the Queue Worker.
 
 You can learn about [asynchronous invocations here](/reference/async).
 
-## Async use cases
-
-Every function in OpenFaaS can be invoked either synchronously or asynchronously. Asynchronous invocations are retried automatically, and can return their response to a given endpoint via a webhook.
-
 Popular use-cases include:
 
 - Batch processing and machine learning
 - Resilient data pipelines
 - Receiving webhooks
 - Long running jobs
 
-On the blog we show reference examples built upon these architectural patterns:
-
-- [Exploring the Fan out and Fan in pattern with OpenFaaS](https://www.openfaas.com/blog/fan-out-and-back-in-using-functions/)
-- [Generate PDFs at scale on Kubernetes using OpenFaaS and Puppeteer](https://www.openfaas.com/blog/pdf-generation-at-scale-on-kubernetes/)
-- [How to process your data the resilient way with back pressure](https://www.openfaas.com/blog/limits-and-backpressure/)
-- [The Next Generation of Queuing: JetStream for OpenFaaS](https://www.openfaas.com/blog/jetstream-for-openfaas/)
-
 ## Terminology
 
 * [NATS](https://nats.io/) - an open source messaging system hosted by the [CNCF](https://www.cncf.io/)

docs/reference/async.md

@@ -11,6 +11,19 @@ Why might you want to use an asynchronous invocation?
 
 You're working with a partner's webhook. They send you data, but if you don't send a HTTP 200 OK within 1 second, they assume failure and retry the message. This works well if your function can complete in less than a second on every invocation, but if there's any risk that it can't, you need another solution. So you will give your partner a URL to the asynchronous function URL instead and it will reply within several milliseconds whilst still processing the data.
 
+Other popular use-cases include:
+
+- Batch processing and machine learning
+- Resilient data pipelines
+- Long running jobs
+
+See these blog posts for examples of asynchronous patterns in practice:
+
+- [Exploring the Fan out and Fan in pattern with OpenFaaS](https://www.openfaas.com/blog/fan-out-and-back-in-using-functions/)
+- [Generate PDFs at scale on Kubernetes using OpenFaaS and Puppeteer](https://www.openfaas.com/blog/pdf-generation-at-scale-on-kubernetes/)
+- [How to process your data the resilient way with back pressure](https://www.openfaas.com/blog/limits-and-backpressure/)
+- [The Next Generation of Queuing: JetStream for OpenFaaS](https://www.openfaas.com/blog/jetstream-for-openfaas/)
+
 ### Synchronous vs asynchronous invocation
 
 * Sync
@@ -110,7 +123,7 @@ There are limits for asynchronous functions, which you should understand before
 * Concurrency / parallelism - the amount of function invocations processed at any one time.
 * Named queues - by default there is one queue, but additional queues can be added. Each named queue can have its own timeout and concurrency.
 * Payload size - the maximum size is configured to be 1MB. The limit is defined by NATS, but can be changed. Use a database, or S3 bucket for storing large payloads, and pass an identifier to function calls.
-* Retries - retries are available in [OpenFaaS Pro](https://openfaas.com/support/) with an exponential back-off.
+* Retries - asynchronous invocations can be retried automatically when a function returns an error. Retries use an exponential back-off algorithm. See: [retries](/openfaas-pro/retries).
 
 The queue-worker uses a single timeout for how long it will spend processing a message, that is called `ack_wait`. If your longest function can run for *25 minutes*, then the `ack_wait` should be set to at least `25m`.