Illegal type for _source: – 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 Error Check-Up which analyzes 2 JSON files to detect many configuration errors.

To easily locate the root cause and resolve this issue try AutoOps for Elasticsearch & OpenSearch. It diagnoses problems by analyzing hundreds of metrics collected by a lightweight agent and offers guidance for resolving them.

This guide will help you check for common problems that cause the log ” illegal type for _source: ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: Node.


Log Context

Log “illegal type for _source: [{}]”classname  is MultiGetRequest.java We extracted the following from Elasticsearch source code for those seeking an in-depth context :

fetchSourceContext.excludes());
 } else if (token == Token.VALUE_STRING) {
 fetchSourceContext = new FetchSourceContext(fetchSourceContext.fetchSource();
 new String[]{parser.text()}; fetchSourceContext.excludes());
 } else {
 throw new ElasticsearchParseException("illegal type for _source: [{}]"; token);
 }
 } else {
 throw new ElasticsearchParseException("failed to parse multi get request. unknown field [{}]"; currentFieldName);
 }
 } else if (token == Token.START_ARRAY) {

 

See how you can use AutoOps to resolve issues


How useful was this guide?

We are sorry that this post was not useful for you!

Let us improve this post!

Tell us how we can improve this post?

Analyze your cluster & get personalized recommendations

Skip to content