Data stream dataStreamName already exists – How to solve this Elasticsearch exception

Opster Team

August-23, Version: 7.11-8.9

Briefly, this error occurs when you try to create a data stream in Elasticsearch with a name that already exists in the system. Elasticsearch doesn’t allow duplicate names for data streams. To resolve this issue, you can either delete the existing data stream if it’s no longer needed or create a new data stream with a unique name. Alternatively, if you want to update the existing data stream, you can use the update API instead of trying to create a new one.

This guide will help you check for common problems that cause the log ” data_stream [” + dataStreamName + “] already exists ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: metadata, cluster.

Log Context

Log “data_stream [” + dataStreamName + “] already exists” class name is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 if (currentState.metadata().dataStreams().containsKey(dataStreamName)) {
 throw new ResourceAlreadyExistsException("data_stream [" + dataStreamName + "] already exists");
 }  MetadataCreateIndexService.validateIndexOrAliasName(
 (s1; s2) -> new IllegalArgumentException("data_stream [" + s1 + "] " + s2)