ITPUB

Aug 9, 2023 · Operations

Why Is My Elasticsearch Cluster Using 15 GB Heap? A Deep Dive into Memory Bottlenecks

The article examines a 7‑node Elasticsearch cluster with 500 million documents, uncovering excessive heap usage, high OS memory pressure, numerous deleted documents, large translog, low query‑cache hit rate, and an over‑sharded design, then offers concrete tuning and redesign recommendations to restore performance.