Deployment Strategies

1. Introduction

Deployment Strategies define how updates to streaming pipelines are rolled out without causing data loss, duplicate processing, or system downtime.

2. Why This Concept Exists

Stopping a streaming pipeline causes upstream buffers (like Pub/Sub queues) to accumulate backlog messages. Swapping pipeline instances requires coordinated strategies to ensure state transitions smoothly.

3. Key Strategies

1. Drain: Stop reading from sources and complete processing all buffered events before turning the runner VM off.
2. Rolling Update: Replacing active workers without interrupting the flow of messages (fully supported in Dataflow).