Distributed Data Processing Flashcards
7 cards from real Data Engineering practice questions. Tap to flip, then mark Knew It or Still Learning โ missed cards come back until you master them.
Read the first 7 Distributed Data Processing flashcards as text
Which delivery guarantee ensures each message is processed once with no duplicates or loss?
Answer: Exactly-once
Exactly-once semantics processes every record one time, avoiding duplicates and drops.
In Kafka, what determines the maximum parallelism of consumers in a group?
Answer: The number of partitions
Each partition is consumed by at most one consumer in a group, capping parallelism.
What is the main trade-off described by the CAP theorem during a network partition?
Answer: Choosing between consistency and availability
Under a partition you must sacrifice either consistency or availability.
A windowed aggregation over event-time streams typically needs which mechanism to handle late data?
Answer: Watermarks
Watermarks define how long to wait for late events before finalizing a window.
Why might increasing the number of partitions improve throughput up to a point?
Answer: More partitions allow more parallel tasks
More partitions enable greater parallelism, but too many add scheduling overhead.
What is a coordinator's role in a two-phase commit protocol?
Answer: Asking participants to prepare, then commit or abort
The coordinator runs prepare and commit phases to keep a distributed transaction atomic.
Which storage format is best suited for analytical column scans across distributed engines?
Answer: Parquet
Parquet's columnar layout lets engines read only needed columns efficiently.