Real-Time Streaming Architectures Flashcards

The Kappa architecture differs from Lambda primarily because it:

Answer: Uses a single stream-processing path for both real-time and reprocessing

Kappa removes the batch layer and reprocesses by replaying the log through one streaming path.

What is a session window in stream processing?

Answer: A window defined by periods of activity separated by inactivity gaps

Session windows group events that occur close together, closing after a configured inactivity gap.

In Kafka, increasing the replication factor primarily improves:

Answer: Fault tolerance and durability

More replicas mean the data survives more broker failures, raising durability.

What is the function of a checkpoint in a stateful stream processor like Flink?

Answer: Persist state snapshots for recovery after failure

Checkpoints periodically snapshot operator state so processing can resume consistently after a crash.

Which serialization format is commonly used with a schema registry for streaming data?

Answer: Avro

Avro pairs well with schema registries to enforce and evolve schemas across producers and consumers.

Processing-time semantics differ from event-time semantics because processing time:

Answer: Uses the clock of the machine processing the event

Processing time relies on the processor's wall clock, not when the event actually occurred.

What problem does a dead-letter queue solve in a streaming system?

Answer: Isolating messages that repeatedly fail processing

A dead-letter queue captures unprocessable messages so the main pipeline keeps flowing.