Incorrect Port Information of the Yarn Client Causes Error "connection refused" After a Task Is Submitted

Issue

The ResourceManager of Yarn that requests to submit jobs throws error "connection refused", and the port number configured for Yarn is 8032.

Symptom

One of Yarn's ResourceManager nodes in the MRS cluster cannot be connected, and the port number configured for Yarn is 8032.

Cause Analysis

The service application runs outside the cluster, and the in-use client does not match the latest client configuration provided by the MRS cluster. The Yarn port is 8032, which is different from the actual port of Yarn's ResourceManager of MRS. As a result, the ResourceManager of Yarn that requests to submit jobs reports error "connection refused".

Procedure

1. Update the MRS client.
2. Submit the job again.