Merging/Reducing the aggregations failed when computing the aggregation – How to solve this Elasticsearch error

Average Read Time

2 Mins

Merging/Reducing the aggregations failed when computing the aggregation – How to solve this Elasticsearch error

Opster Team

July-20, Version: 1.7-8.0

Before you begin reading this guide, we recommend you try running the Elasticsearch Check-Up which can resolve issues that cause many errors.

This guide will help you check for common problems that cause the log ” Merging/Reducing the aggregations failed when computing the aggregation ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: search and aggregations.

Advanced users might want to skip right to the common problems section in each concept or try running the Check-Up to analyze Elasticsearch configuration and help resolve this error.

Log Context

Log “Merging/Reducing the aggregations failed when computing the aggregation [“classname  is InternalMappedRareTerms.java We extracted the following from Elasticsearch source code for those seeking an in-depth context :

if (referenceTerms != null &&
 referenceTerms.getClass().equals(terms.getClass()) == false &&
 terms.getClass().equals(UnmappedRareTerms.class) == false) {
 // control gets into this loop when the same field name against which the query is executed
 // is of different types in different indices.
 throw new AggregationExecutionException("Merging/Reducing the aggregations failed when computing the aggregation ["
 + referenceTerms.getName() + "] because the field you gave in the aggregation query existed as two different "
 + "types in two different indices");
 }
 for (B bucket : terms.getBuckets()) {
 List bucketList = buckets.computeIfAbsent(bucket.getKey(); k -> new ArrayList<>());

 

Watch a demo of the Check-Up:

Analyze your cluster