Correctly record SLM state during master failover

[samxbr]

No description provided.

[Copilot]

Pull Request Overview

Updates SLM to correctly record snapshot statistics during master failover by retrieving and evaluating actual snapshot status rather than assuming failures. This ensures accurate tracking of snapshot success/failure states when the master node is shut down during SLM execution.

Key changes:

• Enhanced WriteJobStatus to accept and process snapshot information for completed registered snapshots
• Added logic to fetch snapshot details for registered snapshots that are no longer running
• Updated test coverage to verify correct stat recording during master failover scenarios

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
SnapshotLifecycleTask.java	Core logic changes to fetch and process snapshot info for accurate stat recording
SnapshotLifecycleTaskTests.java	Updated test cases to reflect new WriteJobStatus method signatures and behavior
SnapshotLifecycleService.java	Added utility method to extract policy ID from job ID
SLMSnapshotBlockingIntegTests.java	Added integration tests for master failover scenarios
RegisteredPolicySnapshots.java	Updated documentation to reflect new behavior

Comments suppressed due to low confidence (1)

x-pack/plugin/slm/src/main/java/org/elasticsearch/xpack/slm/SnapshotLifecycleTask.java:1

• This assertion could cause the application to crash in production if an invalid job ID is passed. Consider throwing a proper exception with descriptive error message instead of using an assertion.

/*

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[Copilot]

This assertion assumes that CreateSnapshotResponse always contains snapshot info for completed snapshots, but this may not hold true in all edge cases. Consider using a null check with appropriate error handling instead of an assertion.

Suggested change

	assert snapInfo != null : "completed snapshot info is null";
	if (snapInfo == null) {
	logger.warn("CreateSnapshotResponse did not contain snapshot info for completed snapshot [{}]", request.snapshot());
	onFailure(new ElasticsearchException("Snapshot info is null for completed snapshot [" + request.snapshot() + "]"));
	return;
	}