Briefly, this error occurs when Elasticsearch fails to update a snapshot in the repository. This could be due to insufficient permissions, network connectivity issues, or the repository being read-only. To resolve this, you can check and adjust the repository permissions, ensure the network connection is stable, or change the repository from read-only to read-write. Additionally, ensure that the snapshot you’re trying to update actually exists in the repository.
This guide will help you check for common problems that cause the log ” failed to update snapshot in repository ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: blobstore, repositories, snapshot, 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 “failed to update snapshot in repository” class name is BlobStoreRepository.java. We extracted the following from Elasticsearch source code for those seeking an in-depth context :
// If there are older version nodes in the cluster; we don't need to run this cleanup as it will have already happened
// when writing the index-${N} to each shard directory.
final Version repositoryMetaVersion = finalizeSnapshotContext.repositoryMetaVersion();
final boolean writeShardGens = SnapshotsService.useShardGenerations(repositoryMetaVersion);
final Consumer onUpdateFailure = e -> finalizeSnapshotContext.onFailure(
new SnapshotException(metadata.name(); snapshotId; "failed to update snapshot in repository"; e)
); final Executor executor = threadPool.executor(ThreadPool.Names.SNAPSHOT); final boolean writeIndexGens = SnapshotsService.useIndexGenerations(repositoryMetaVersion);
