juniorApache Spark
What is Apache Spark and how does it differ from MapReduce?
Updated May 5, 2026
Short answer
Apache Spark is a distributed computing framework that performs in-memory processing, making it significantly faster than the disk-based MapReduce.
Deep explanation
Spark provides a unified engine for batch, streaming, and SQL workloads. Unlike MapReduce, which persists data to disk after every map and reduce step, Spark keeps data in RAM whenever possible, reducing I/O overhead. It also utilizes a Directed Acyclic Graph (DAG) for execution planning, allowing for multi-stage optimizations.
Real-world example
Using Spark for real-time log analysis where speed is critical to identify security threats within seconds.
Common mistakes
- Thinking Spark is a database
- it is a processing engine, not a storage layer.
Follow-up questions
- What is RDD?
- Can Spark run without Hadoop?