Briefly, this error occurs when Elasticsearch is unable to record a snapshot due to missing lifecycle metadata. This could be due to a misconfiguration or deletion of the snapshot lifecycle policy. To resolve this issue, you can either recreate the missing lifecycle policy or update the existing one to ensure it has the correct metadata. Additionally, check the Elasticsearch logs for more detailed error messages that could help identify the root cause.
This guide will help you check for common problems that cause the log ” failed to record snapshot [{}] for snapshot [{}] in policy [{}]: snapshot lifecycle metadata is null ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: snapshot, plugin, metadata.
Overview
Metadata in Elasticsearch refers to additional information stored for each document. This is achieved using the specific metadata fields available in Elasticsearch. The default behavior of some of these metadata fields can be customized during mapping creation.
Examples
Using _meta meta-field for storing application-specific information with the mapping:
PUT /my_index?pretty
{
"mappings": {
"_meta": {
"domain": "security",
"release_information": {
"date": "18-01-2020",
"version": "7.5"
}
}
}
}Notes
- In version 2.x, Elasticsearch had a total 13 meta fields available, which are: _index, _uid, _type, _id, _source, _size, _all, _field_names, _timestamp, _ttl, _parent, _routing, _meta
- In version 5.x, _timestamp and _ttl meta fields were removed.
- In version 6.x, the _parent meta field was removed.
- In version 7.x, _uid and _all meta fields were removed.
Log Context
Log “failed to record snapshot [{}] for snapshot [{}] in policy [{}]: snapshot lifecycle metadata is null” classname is SnapshotLifecycleTask.java.
We extracted the following from Elasticsearch source code for those seeking an in-depth context :
public ClusterState execute(ClusterState currentState) throws Exception {
SnapshotLifecycleMetadata snapMeta = currentState.metadata().custom(SnapshotLifecycleMetadata.TYPE);
assert snapMeta != null : "this should never be called while the snapshot lifecycle cluster metadata is null";
if (snapMeta == null) {
logger.error("failed to record snapshot [{}] for snapshot [{}] in policy [{}]: snapshot lifecycle metadata is null";
exception.isPresent() ? "failure" : "success"; snapshotName; policyName);
return currentState;
}
Map snapLifecycles = new HashMap(snapMeta.getSnapshotConfigurations());
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