Distributed Systems

Posts in this series: A Primer Document Coordination Document Example Dispatching Example Failures and Retries Failure Recovery Sagas Sample code from this series So far in this series, we've looked at the ins and outs of moving beyond distributed transactions using persisted messages as a means of coordination between different documents (or resources). One common question in the example I give is "how do I actually make sure either both [Read More]

Posts in this series: A Primer Document Coordination Document Example Dispatching Example Failures and Retries Failure Recovery Sagas Sample code from this series In the last post, we looked at how we can recover from exceptions from inside our code handling messages. We perform some action in our document, and something goes wrong. But what happens when something goes wrong during the dispatch process: If our dispatcher itself fails, either: [Read More]

Posts in this series: A Primer Document Coordination Document Example Dispatching Example Failures and Retries Failure Recovery Sagas Sample code from this series In the last post, we looked at an example of dispatching document messages to other documents using a central dispatcher. Our example worked well in the happy path scenario, but what happens when something goes wrong? We of course do not want a failure in dispatching messages [Read More]

Posts in this series: A Primer Document Coordination Document Example Dispatching Example Failures and Retries Failure Recovery Sagas Sample code from this series In the last post, we looked at refactoring our documents to use messaging to communicate changes. We're still missing something, however - the dispatcher: Our dispatcher is the main component that facilitates document communication. For a given document, it needs to: Read messages out of a document's [Read More]

Posts in this series: A Primer Document Coordination Document Example Dispatching Example Failures and Retries Failure Recovery Sagas Sample code from this series In the last post, I walked through the "happy path" scenario of coordinated communication/activities between multiple resources that otherwise can't participate in a transaction. In this post, I'll walk through a code example of building out document coordination in Azure Cosmos DB. My starting point is [Read More]