Updating index.compound-format from to – How to solve related issues

Updating index.compound-format from to – 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 can resolve issues that cause many errors.

This guide will help you check for common problems that cause the log ” Updating index.compound-format from to ” to appear. It’s important to understand the issues related to the log, so to get started, read the general overview on common issues and tips related to the Elasticsearch concepts: index, merge and shard.

Advanced users might want to skip right to the common problems section in each concept or try running the Check-Up which analyses ES to pinpoint the cause of many errors and provides suitable actionable recommendations how to resolve them (free tool that requires no installation).

Log Context

Log “updating index.compound_format from [{}] to [{}]” classname is MergePolicyConfig.java.
We extracted the following from Elasticsearch source code for those seeking an in-depth context :


        double noCFSRatio = parseNoCFSRatio(settings.get(INDEX_COMPOUND_FORMAT; Double.toString(MergePolicyConfig.this.noCFSRatio)));
        if (noCFSRatio != MergePolicyConfig.this.noCFSRatio) {
            logger.info("updating index.compound_format from [{}] to [{}]"; formatNoCFSRatio(MergePolicyConfig.this.noCFSRatio); formatNoCFSRatio(noCFSRatio));
            MergePolicyConfig.this.noCFSRatio = noCFSRatio;


Run the Check-Up to get a customized report like this:

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