A durable function is an AWS Lambda function that might run for minutes, days, or even up to a year. You build these functions with the Durable Execution SDK, which provides operations such as steps, waits, and parallel. A single durable execution might be spread across many Lambda invocations, with waits and retries in between. So observing a durable execution, made of many invocations, needs different tools. The question that you want answered is rarely “what did this invocation do?” It’s “how far did my durable execution get, which step failed, how many times did it retry, and how long did the whole thing take?”
After you run thousands of executions, the questions widen from one execution to all of them. Some questions are operational. Which step fails most often, and with which error? Which step causes the most retries? Did a step get slower after last week’s deployment? Other questions are about the business the workflow runs. Which customers did…
