Episode 351 - Bernd Rücker on Orchestrating Microservices with Workflow Management

Bernd Rücker, who has contributed to multiple open source
workflow management projects, discusses orchestrating
microservices with workflow management.  As distributed
systems evolve into a family of microservices that must handle
long-running stateful processes with time-dependent actions,
events, multiple paths through the system, and complex rollbacks,
the workflow management model provides a way to ensure clear
modeling, correctness, and separation of concerns.  
Rücker recommends a federated model in which each microservice is
paired with its own workflow to handle retries and other policies
and failure modes around that service.  Robert Blumen spoke
with Rücker about microservice architecture, event-driven
systems, long-running stateful processes versus synchronous
request/response, event handling, time-outs, and handling
exceptional conditions with compensating transactions. Rücker
compares the choreography versus orchestration models for
collaboration and discusses why orchestration provides a better
separation of concerns.  The discussion delves into the
implementation of workflow management systems including
persistence, scaling, event handling, timers and scheduling, and
similarities to CQRS.  The discussion wraps up with
monitoring and visualization.