Briefly, this error occurs when Elasticsearch tries to delete a snapshot that doesn’t exist in the specified repository. This could be due to a typo in the snapshot name or the snapshot was already deleted. To resolve this, ensure the snapshot name is correct and exists in the repository. If the snapshot was already deleted, no action is needed. If the error persists, check the repository’s health and configuration.
This guide will help you check for common problems that cause the log ” Attempting to remove non-existent snapshot [{}] from repository data ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: snapshot, repositories, repository.
Overview
An Elasticsearch snapshot provides a backup mechanism that takes the current state and data in the cluster and saves it to a repository (read snapshot for more information). The backup process requires a repository to be created first. The repository needs to be registered using the _snapshot endpoint, and multiple repositories can be created per cluster. The following repository types are supported:
Repository types
| Repository type | Configuration type |
|---|---|
| Shared file system | Type: “fs” |
| S3 | Type : “s3” |
| HDFS | Type :“hdfs” |
| Azure | Type: “azure” |
| Google Cloud Storage | Type : “gcs” |
Examples
To register an “fs” repository:
PUT _snapshot/my_repo_01
{
"type": "fs",
"settings": {
"location": "/mnt/my_repo_dir"
}
}Notes and good things to know
- S3, HDFS, Azure and Google Cloud require a relevant plugin to be installed before it can be used for a snapshot.
- The setting, path.repo: /mnt/my_repo_dir needs to be added to elasticsearch.yml on all the nodes if you are planning to use the repo type of file system. Otherwise, it will fail.
- When using remote repositories, the network bandwidth and repository storage throughput should be high enough to complete the snapshot operations normally, otherwise you will end up with partial snapshots.
Log Context
Log “Attempting to remove non-existent snapshot [{}] from repository data” class name is RepositoryData.java. We extracted the following from Elasticsearch source code for those seeking an in-depth context :
public RepositoryData removeSnapshot(final SnapshotId snapshotId; final ShardGenerations updatedShardGenerations) {
Map newSnapshotIds = snapshotIds.values().stream()
.filter(id -> !snapshotId.equals(id))
.collect(Collectors.toMap(SnapshotId::getUUID; Function.identity()));
if (newSnapshotIds.size() == snapshotIds.size()) {
throw new ResourceNotFoundException("Attempting to remove non-existent snapshot [{}] from repository data"; snapshotId);
}
Map newSnapshotStates = new HashMap<>(snapshotStates);
newSnapshotStates.remove(snapshotId.getUUID());
final Map newSnapshotVersions = new HashMap<>(snapshotVersions);
newSnapshotVersions.remove(snapshotId.getUUID());
