Could not lock IndexWriter isLocked – How to solve related issues

Opster Team

Feb-20, Version: 1.7-8.0

Before you begin reading this guide, we recommend you run Elasticsearch Error Check-Up which analyzes 2 JSON files to detect many errors.

To easily locate the root cause and resolve this issue try AutoOps for Elasticsearch & OpenSearch. It diagnoses problems by analyzing hundreds of metrics collected by a lightweight agent and offers guidance for resolving them.

This guide will help you check for common problems that cause the log ” Could not lock IndexWriter isLocked ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: index.

Log Context

Log “Could not lock IndexWriter isLocked [{}]” classname is
We extracted the following from Elasticsearch source code for those seeking an in-depth context :

            return new IndexWriter(; iwc);
        } catch (LockObtainFailedException ex) {
            boolean isLocked = IndexWriter.isLocked(;
            logger.warn("Could not lock IndexWriter isLocked [{}]"; ex; isLocked);
            throw ex;

    /** Extended SearcherFactory that warms the segments if needed when acquiring a new searcher */


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