Messaging

Applications in the cloud can be subjected to heavy peaks of traffic in intermittent phases. If our applications can’t handle these peaks, this can lead to performance, availability and reliability issues. For example, imagine we have an application that stores state temporarily in a cache. We could have a single task within our application that performs this for us, and we could have a good idea of how many times a single instance of our application would perform this task....

The Priority Queue pattern is a pattern that allows us to prioritize requests sent to services so that higher priority requests are received and processed faster than lower priority requests. This is useful for when we are building applications where we need to prioritize some clients over others, or if some requests need to be processed faster than usual for business/compliance reasons. In this article, I’ll talk about what the Priority Queue pattern is, what advantages priority queues can provide, what we need to consider when implementing the Priority Queue pattern and how can implement it priority queues in Azure (Spoiler alert, it’s a little hacky!...

Applications running in the cloud should expect to handle a large number of requests. One method of dealing with large amounts of requests is to pass them through a message broker to a consumer service that handles these requests asynchronously. This helps ensure that requests are being processed without throttling or degrading the performance of our applications. The volume of these requests can vary over a period of time. Imagine that you’re a developer for an e-commerce website....

The Claim-Check pattern, or Reference-Based Messaging, is a pattern where we split a large message into a claim check and a payload. The claim check is sent to our message broker and the payload will be stored in an external data store. This pattern enables us to process large messages, while preventing our message bus from being overloaded and prevent our client applications slowing down. We can also reduce costs with this pattern, but utilizing cheap storage alternatives rather than increasing the resource units used by our message broker....

In event-driven architectures, communicating between different microservices via messages can be enabled using Publish and Subscribe functionality (Pub/Sub for short). The publisher (or producer) writes messages to a message topic (or queue), while a subscriber will subscribe to that particular topic and receives the message. Both the publisher and subscriber are unaware of which application either produced or subscribed to the topic. This pattern is useful when we want to send messages to different services, while ensuring that they are decoupled from each other....