Briefly, this error occurs when Elasticsearch is unable to delete old snapshots due to issues like insufficient permissions, incorrect snapshot name, or connectivity problems with the snapshot repository. To resolve this, you can check and correct the snapshot name, ensure the Elasticsearch process has the necessary permissions to delete snapshots, and verify the connectivity and accessibility of the snapshot repository. Also, ensure that the snapshot is not currently in use or being created, as this can prevent deletion.
This guide will help you check for common problems that cause the log ” [{}] failed to delete snapshot [{}] for retention ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: snapshot, plugin, delete.
Overview
DELETE is an Elasticsearch API which removes a document from a specific index. This API requires an index name and _id document to delete the document.
Delete a document
DELETE /my_index/_doc/1
Notes
- A delete request throws 404 error code if the document does not already exist in the index.
- If you want to delete a set of documents that matches a query, you need to use delete by query API.
Log Context
Log “[{}] failed to delete snapshot [{}] for retention” classname is SnapshotRetentionTask.java.
We extracted the following from Elasticsearch source code for those seeking an in-depth context :
.execute(ActionListener.wrap(acknowledgedResponse -> { slmStats.snapshotDeleted(slmPolicy); listener.onResponse(acknowledgedResponse); }; e -> { try { logger.warn(new ParameterizedMessage("[{}] failed to delete snapshot [{}] for retention"; repo; snapshot); e); slmStats.snapshotDeleteFailure(slmPolicy); } finally { listener.onFailure(e); } }));