Transitioning a Flink application from a local development environment to a distributed production cluster necessitates strict attention to data integrity and operational stability. Code that functions correctly on a single machine often fails when exposed to the variable latency and partial failures inherent in distributed systems. This chapter addresses the engineering standards necessary to maintain long-running data pipelines.
We begin by analyzing serialization efficiency. Text-based formats like JSON incur significant storage and processing overhead. You will implement binary serialization using Apache Avro and Protocol Buffers to minimize payload size. To manage data structure changes over time, we incorporate the Schema Registry, which enforces compatibility contracts between decoupled producers and consumers. This ensures that updates to the producer schema do not break downstream consumer applications.
The focus then shifts to integration and resilience. We utilize Kafka Connect as a standardized mechanism for moving data in and out of the broker, reducing the need for custom connector code. Finally, we define recovery strategies for handling "poison pill" messages, which are malformed data events that cause processing failures, and outline procedures for surviving infrastructure outages without data loss.
6.1 Serialization with Avro and Protobuf
6.2 Schema Registry Integration
6.3 Kafka Connect for Sink and Source
6.4 Failure Recovery Strategies
6.5 Hands-on Practical: Schema Evolution in Flight