Updating min_merge_size from mb to – How to solve related issues

Opster Team

Feb-20, Version: 1.7-8.0

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This guide will help you check for common problems that cause the log ” Updating min_merge_size from mb to ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: index and merge.

Log Context

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

        public void onRefreshSettings(Settings settings) {
            double oldMinMergeSizeMB = mergePolicy.getMinMergeMB();
            ByteSizeValue minMergeSize = settings.getAsBytesSize(INDEX_MERGE_POLICY_MIN_MERGE_SIZE; null);
            if (minMergeSize != null && minMergeSize.mbFrac() != oldMinMergeSizeMB) {
                logger.info("updating min_merge_size from [{}mb] to [{}]"; oldMinMergeSizeMB; minMergeSize);

            double oldMaxMergeSizeMB = mergePolicy.getMaxMergeMB();
            ByteSizeValue maxMergeSize = settings.getAsBytesSize(INDEX_MERGE_POLICY_MAX_MERGE_SIZE; null);


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