HDDS-13758. Adding replicated size in nsummary and related changes

[priyeshkaratha]

What changes were proposed in this pull request?

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[gemini-code-assist]

Summary of Changes

Hello @priyeshkaratha, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This PR introduces and integrates 'replicated size' into Apache Ozone's Recon service. It adds a replicatedSizeOfFiles field to the NSSummary data structure, updates the logic for calculating and propagating this metric through the directory hierarchy, and modifies API endpoints to expose it. A new upgrade action ensures that existing deployments correctly populate this field upon upgrade. Comprehensive tests have been added or updated to validate the new functionality across different replication configurations.

Highlights

• Intent: This pull request introduces the concept of 'replicated size' to Recon's namespace summary (NSSummary) and related insights. The goal is to provide accurate storage usage metrics that account for data replication, alongside the existing unreplicated data size.
• Key Changes: The core change involves adding a replicatedSizeOfFiles field to the NSSummary data structure and updating all relevant logic in Recon to correctly calculate, persist, and expose this new metric. This includes modifications to how NSSummaries are built, updated, serialized, and queried. An upgrade action is also introduced to ensure existing deployments correctly populate this new field upon upgrade.
• Detailed Changes: 1. NSSummary and Codec: A new replicatedSizeOfFiles field was added to NSSummary.java, along with corresponding constructors, getters, and setters. The NSSummaryCodec.java was updated to serialize and deserialize this new field, ensuring its persistence.

2. NSSummary Task Event Handler: NSSummaryTaskDbEventHandler.java was modified to track and propagate replicatedSizeOfFiles changes up the directory hierarchy during key and directory put/delete events. The propagateSizeUpwards method now accepts and updates replicated size.
3. API Endpoints: OMDBInsightEndpoint.java was updated to retrieve and expose both unreplicated and replicated sizes for deleted directories. FSOBucketHandler.java was simplified to directly use the aggregated replicatedSizeOfFiles from NSSummary for calculating disk usage under an object.
4. Upgrade Action: A new ReconLayoutFeature.REPLICATED_SIZE_OF_FILES (version 4) was added, along with a ReplicatedSizeOfFilesUpgradeAction.java. This upgrade action triggers a full rebuild of the NSSummary tree during finalization, ensuring that the new replicatedSizeOfFiles field is correctly populated for all existing data.
5. Testing Enhancements: Integration tests (TestReconInsightsForDeletedDirectories.java, TestOmDBInsightEndPoint.java, TestNSSummaryTaskWithFSO.java) were updated to be parameterized with various replication configurations (RATIS, EC) and include assertions for the new replicatedSizeOfFiles and replicatedDataSize metrics. Helper methods in TestDataUtil.java were extended to support specifying replication configurations during bucket creation for tests. A new unit test (TestReplicatedSizeOfFilesUpgradeAction.java) was added to verify the upgrade action's functionality.

• Testing: The changes are covered by extensive unit and integration tests. Existing tests for Recon insights and NSSummary functionality were enhanced to include assertions for the new replicated size metric across various replication types (RATIS, EC). A dedicated test was added for the upgrade action to ensure proper NSSummary rebuild.

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[gemini-code-assist]

Code Review

This pull request introduces the replicatedSizeOfFiles field to NSSummary to track replicated data size, which is a significant enhancement for accurate disk usage reporting. The changes are well-integrated across the data model, serialization, business logic, and API endpoints. The tests have been effectively updated and parameterized to cover different replication configurations, which is great. I've identified a potential NullPointerException and a minor logging issue that should be addressed. Overall, this is a solid contribution.

[gemini-code-assist]

nsSummary can be null if getNSSummary(parentId) returns null (e.g., for an empty or unprocessed directory). This would cause a NullPointerException when nsSummary.getReplicatedSizeOfFiles() is called. A null check is needed to prevent this.

Suggested change

	return nsSummary.getReplicatedSizeOfFiles();
	return nsSummary != null ? nsSummary.getReplicatedSizeOfFiles() : 0L;

[gemini-code-assist]

The log message seems to contain a copy-paste error. It mentions NSSummaryAggregatedTotalsUpgrade action, but this code is in ReplicatedSizeOfFilesUpgradeAction. This could be confusing during debugging. Please correct the action name in the log message.

Suggested change

	"during NSSummaryAggregatedTotalsUpgrade action, will be retried as part of syncDataFromOM " +
	"during ReplicatedSizeOfFilesUpgradeAction, will be retried as part of syncDataFromOM " +