Apache Kafka, Purgatory, and Hierarchical Timing Wheels | Confluent

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Introduced a new implementation for Kafka's request purgatory using Hierarchical Timing Wheels and doubly linked lists. This redesign addresses memory exhaustion and performance bottlenecks of the previous DelayQueue-based implementation by enabling immediate deletion of completed requests and reducing the overhead of the purge process. Benchmarks demonstrate substantial improvements in request throughput and CPU efficiency.