Iteration order of ” + bucketOrds + ” changed without mutating. – How to solve this Elasticsearch error

Opster Team

July-20, Version: 1.7-8.0

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This guide will help you check for common problems that cause the log ” Iteration order of ” + bucketOrds + ” changed without mutating. ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: search and aggregations.

Log Context

Log “Iteration order of [” + bucketOrds + “] changed without mutating. [“classname  is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

for (int ordIdx = 0; ordIdx < owningBucketOrds.length; ordIdx++) {
 List buckets = new ArrayList<>((int) bucketOrds.size());
 LongKeyedBucketOrds.BucketOrdsEnum ordsEnum = bucketOrds.ordsEnum(owningBucketOrds[ordIdx]);
 while( {
 if (bucketOrdsToCollect[b] != ordsEnum.ord()) {
 throw new AggregationExecutionException("Iteration order of [" + bucketOrds + "] changed without mutating. ["
 + ordsEnum.ord() + "] should have been [" + bucketOrdsToCollect[b] + "]");
 buckets.add(; bucketDocCount(ordsEnum.ord()); subAggregationResults[b++]));
 results[ordIdx] =[ordIdx]; buckets);


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