Failed to build json for alias request – 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.

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This guide will help you check for common problems that cause the log ” Failed to build json for alias request ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: request, metadata, alias and cluster.

Log Context

Log “Failed to build json for alias request”classname  is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

try {
 XContentBuilder builder = XContentFactory.jsonBuilder().map(filter);
 this.filter = new CompressedXContent(BytesReference.bytes(builder));
 return this;
 } catch (IOException e) {
 throw new ElasticsearchGenerationException("Failed to build json for alias request"; e);
 public Builder routing(String routing) {
 this.indexRouting = routing;


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