What is executor in Apache spark?

Executors in Apache Spark are the worker nodes that assist the process of operating the individual tasks in the given job of Apache Spark. Executors are launched at the beginning of a spark application and run for the lifetime. Executors also offer in-memory storage for the RDDs of the Spark that are in return cached by the user programs through the Block manager.

Executors also send metrics of the heartbeats through the Heartbeat Sender Threads. Executors can also be identified through the hostname, id, classpath or environment. The executors in the backends extensively manage the executors present in the Apache spark.