Unexpected NullPointerException thrown from a Connection Pool

Products

• VMware Tanzu Gemfire

Issue/Introduction

Symptoms:

This article provides a detailed discussion of the "Pool unexpected java.lang.NullPointerException..." log message. 

When executing operations on a server-side Partitioned region from multiple threads concurrently using a single client connection pool, a Java GemFire client may get the following unexpected NullPointerException.

Client Side your Application Log Message extracted from the caught exception:

Pool unexpected java.lang.NullPointerException connection=Pooled Connection to xxx.xxx.xxx.xxx:xxxxx: Connection[DESTROYED]

Environment

Cause

This NullPointerException is thrown because multiple threads attempt to update the Partitioned region bucket's metadata for the same connection pool.

Resolution

This NullPointerException can be ignored as a harmless exception since, at least, one of the threads should succeed in updating the target metadata.