Performance Degradation Observed When Using removeAll(keys) Instead of clear() in Replicated GemFire Regions

Products

• VMware Tanzu Gemfire

Issue/Introduction

region.removeAll(keys) is significantly slower than region.clear()

Resolution

The observed performance difference is due to the intrinsic behavior of the two APIs:

region.clear() 

• Internally optimized for clearing all entries at once.

• Minimal messaging overhead across replicas.

• Does not trigger per-entry events (e.g., cache listeners, indexes, WAN events).

• Ideal for clearing all data from a region efficiently.

Refer to the official documentation: About Region.clear() Operations

region.removeAll(keys)

• Iterates through and removes each key individually.

• Triggers per-key operations (destroy events, listeners, indexes).

• Involves more inter-node communication and event propagation.

• Performance depends on the number of keys and event processing overhead.

Refer to the official documentation: The removeAll Operation