No bucket defined for s3 repository – How to solve this Elasticsearch exception

Opster Team

August-23, Version: 6.8-8.9

Briefly, this error occurs when Elasticsearch is trying to use an S3 repository for snapshot or backup purposes, but the bucket for the repository is not defined. To resolve this issue, you can either define the bucket in the repository settings or create a new bucket in S3. Make sure the Elasticsearch cluster has the necessary permissions to access the S3 bucket. Also, ensure that the bucket name is correctly spelled and exists in the specified region.

This guide will help you check for common problems that cause the log ” No bucket defined for s3 repository ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: repository, repository-s3, repositories.

Log Context

Log “No bucket defined for s3 repository” class name is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 this.service = service;  // Parse and validate the user's S3 Storage Class setting
 this.bucket = BUCKET_SETTING.get(metadata.settings());
 if (bucket == null) {
 throw new RepositoryException(; "No bucket defined for s3 repository");
 }  this.bufferSize = BUFFER_SIZE_SETTING.get(metadata.settings());
 this.chunkSize = CHUNK_SIZE_SETTING.get(metadata.settings());