What is the default port number for a standalone Spark cluster?

In a standalone Spark cluster, the default port number used for the cluster manager is 7077. This port is crucial for the Spark driver to communicate with the cluster manager to launch applications and allocate resources. When you set up a Spark application in standalone mode, the driver program connects to this port to interact with the cluster, thereby managing the execution and scheduling of tasks across the worker nodes.

While other ports mentioned in the choices serve significant purposes within the Spark ecosystem, they do not relate to the standalone cluster manager's default configuration. For instance, port 8080 is typically used for the web UI to monitor Spark applications, 4040 is the default port for the Spark application's web UI, and 5000 does not have a specific default relevance in this context. Recognizing the unique roles of these ports helps clarify the communication protocol within the Spark framework.