_count must be the last element in the path – 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 ” _count must be the last element in the path ” 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 “_count must be the last element in the path”classname  is InternalMultiBucketAggregation.java We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 Aggregations aggregations = getAggregations();
 String aggName = path.get(0);
 if (aggName.equals("_count")) {
 if (path.size() > 1) {
 throw new InvalidAggregationPathException("_count must be the last element in the path");
 return getDocCount();
 } else if (aggName.equals("_key")) {
 if (path.size() > 1) {
 throw new InvalidAggregationPathException("_key must be the last element in the path");


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