Failed to parse object empty key – How to solve this Elasticsearch exception

Opster Team

August-23, Version: 6.8-8.9

Briefly, this error occurs when Elasticsearch tries to parse a JSON object that contains an empty key. This is not allowed in JSON syntax and hence the parsing fails. To resolve this issue, you can inspect the JSON object and ensure that all keys have valid non-empty values. Alternatively, you can use a tool to validate your JSON before sending it to Elasticsearch. If you’re generating the JSON programmatically, check your code to ensure it doesn’t produce empty keys.

This guide will help you check for common problems that cause the log ” Failed to parse object: empty key ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: .

Log Context

Log “Failed to parse object: empty key” class name is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 // if we didn't find a delimiter we ignore the object or array for forward compatibility instead of throwing an error
 } else {
 throw new ParsingException(parser.getTokenLocation(); "Failed to parse object: empty key");
 }  /**
 * Parses a list of a given type from the given {@code parser}. Assumes that the parser is currently positioned on a


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