GC did bring memory usage down before after allocations duration – How to solve this Elasticsearch error

Opster Team

Aug-23, Version: 7.9-7.15

Briefly, this error occurs when Elasticsearch’s Garbage Collection (GC) process is unable to free up enough memory after several allocation attempts. This could be due to insufficient heap size, memory leaks, or excessive indexing. To resolve this issue, you can increase the heap size, ensure your queries are optimized to prevent memory leaks, or reduce the indexing rate. Additionally, consider upgrading your Elasticsearch version if it’s outdated, as newer versions often have improved memory management.

This guide will help you check for common problems that cause the log ” GC did bring memory usage down; before [{}]; after [{}]; allocations [{}]; duration [{}] ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: memory, indices, breaker.

Log Context

Log “GC did bring memory usage down; before [{}]; after [{}]; allocations [{}]; duration [{}]” classname is HierarchyCircuitBreakerService.java.
We extracted the following from Elasticsearch source code for those seeking an in-depth context :


            final long current = currentMemoryUsageSupplier.getAsLong();
            if (current