Distributed Systems

Posts in this series: A Primer Document Coordination Document Example Dispatching Example Failures and Retries Failure Recovery Sagas Relational Resources Conclusion We started out with a common, but nearly always overlooked problem: how do we reliably coordinate activities between different transactional resources? The question we need to ask first is - do we need to coordinate these activities? Ultimately, it's a business decision about how to deal with the messiness [Read More]

Posts in this series: A Primer Document Coordination Document Example Dispatching Example Failures and Retries Failure Recovery Sagas Relational Resources Conclusion Sample code from this series So far in this series we've mainly concerned ourselves with a single resource that can't support distributed (or multi-entity) transactions. While that is becoming less common as NoSQL options, as Azure CosmosDB supports them, and with the 4.0 release, MongoDB now supports multi-document [Read More]

Posts in this series: A Primer Document Coordination Document Example Dispatching Example Failures and Retries Failure Recovery Sagas Relational Resources Conclusion 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 [Read More]

Posts in this series: A Primer Document Coordination Document Example Dispatching Example Failures and Retries Failure Recovery Sagas Relational Resources Conclusion 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 [Read More]

Posts in this series: A Primer Document Coordination Document Example Dispatching Example Failures and Retries Failure Recovery Sagas Relational Resources Conclusion 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 [Read More]