Stateful Applications in the Age of Durable Execution: Marc Klefter
Durable execution is an emerging programming model, offered by vendors such as Temporal and Azure Functions, for developing resilient, distributed applications with ease, wherein a ”durable function” – a unit of execution guaranteed to run to completion – orchestrates a business process and encapsulates state. However, if an application is made up of these functions, and parts – or even all – of its state is stored alongside each function, what impact does that have on data modeling and retention, supporting complex updates and queries that span multiple workflows, concurrent access, and other issues related to managing state in this type of system architecture? This session explores durable execution in the context of designing, implementing and operating stateful applications; hands-on examples will demonstrate how a durable function ensures robustness, correctness and efficiency in writing and reading state while eliminating the need for locks and having to deal with race conditions, lost or duplicate updates, and stale views. The discussion will also cover scenarios that require the use of an external database and outline strategies for evolving application state as new versions of function code are deployed.
