feat: add region_statistics table

[WenyXu]

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Refer to a related PR or issue link (optional)

What's changed and what's your intention?

Add region_statistics table

mysql> select * from information_schema.region_statistics;
+---------------+----------+---------------+---------------+---------------+-----------+--------+-------------+
| region_id     | table_id | region_number | memtable_size | manifest_size | sst_size  | engine | region_role |
+---------------+----------+---------------+---------------+---------------+-----------+--------+-------------+
| 4440996184064 |     1034 |             0 |       3586817 |         11704 | 301876450 | mito   | Leader      |
| 4432406249472 |     1032 |             0 |     269686817 |         12508 | 279053485 | mito   | Leader      |
| 4445291151360 |     1035 |             0 |      56686817 |          9232 | 297195520 | mito   | Leader      |
| 4436701216768 |     1033 |             0 |     239386817 |          9139 | 281388451 | mito   | Leader      |
+---------------+----------+---------------+---------------+---------------+-----------+--------+-------------+
4 rows in set (0.01 sec)

Checklist

• I have written the necessary rustdoc comments.
• I have added the necessary unit tests and integration tests.
• This PR requires documentation updates.

Summary by CodeRabbit

• New Features

  • Introduced a new error variant for handling region statistics.
  • Added functionality to retrieve region statistics from the cluster.
  • Expanded the information schema to include region statistics.
  • Implemented a comprehensive mechanism for managing and retrieving region statistics.

• Bug Fixes

  • Enhanced error handling for JSON serialization and deserialization.

• Documentation

  • Updated documentation to reflect the new region statistics features and error handling improvements.

[coderabbitai]

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Walkthrough

The pull request introduces several enhancements across multiple files, primarily focusing on error handling and the management of region statistics in a catalog system. Key changes include the addition of new error variants to handle JSON serialization issues, updates to the KvBackendCatalogManager struct for improved metadata management, and the introduction of a new module for region statistics within the information schema. These modifications collectively enhance the functionality and robustness of the system.

Changes

Files	Change Summary
src/catalog/src/error.rs	Added new error variant ListRegionStats to handle listing region statistics. Updated ErrorExt implementation to accommodate the new variant.
src/catalog/src/kvbackend/manager.rs	Enhanced KvBackendCatalogManager struct by adding fields for managing metadata, partition rules, caching, and procedures.
src/catalog/src/system_schema/information_schema.rs	Introduced a new module region_statistics and updated SystemSchemaProviderInner to handle REGION_STATISTICS, integrating it into the information schema.
src/catalog/src/system_schema/information_schema/region_statistics.rs	Implemented InformationSchemaRegionStatistics struct for region statistics, including methods for schema retrieval and data streaming. Added a builder for constructing region statistics.
src/catalog/src/system_schema/information_schema/table_names.rs	Added constant REGION_STATISTICS for referencing the new region statistics table within the information schema.
src/common/catalog/src/consts.rs	Introduced constant INFORMATION_SCHEMA_REGION_STATISTICS_TABLE_ID with value 35 for the new region statistics table.
src/common/meta/src/cluster.rs	Added asynchronous method list_region_stats to ClusterInfo trait for retrieving region statistics.
src/common/meta/src/datanode.rs	Created structures for managing datanode statistics, including Stat, RegionStat, and methods for handling datanode state and statistics.
src/common/meta/src/error.rs	Added new error variants SerializeToJson, DeserializeFromJson, and InvalidStatKey to enhance error handling related to JSON operations and invalid keys. Updated ErrorExt for new error variants.

Possibly related PRs

• feat: add json data type #4619: The main PR introduces a new variant in the Error enum to handle errors related to listing region statistics, while the retrieved PR adds a JSON data type and related functionality, which may involve error handling for JSON operations.

Suggested reviewers

• v0y4g3r
• evenyag
• waynexia
• discord9

🐇 In the meadow where data flows,
New stats for regions now brightly glows.
Errors handled with care and grace,
In our catalog, they find their place.
With every change, our system grows,
Hopping forward, as progress shows! 🌼

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[WenyXu]

@coderabbitai summary

[coderabbitai]

✅ Actions performed

Summary regeneration triggered.

[codecov]

Codecov Report

Attention: Patch coverage is 65.58704% with 170 lines in your changes missing coverage. Please review.

Project coverage is 84.21%. Comparing base (cd4bf23) to head (fc4b0d7).
Report is 4 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4771      +/-   ##
==========================================
- Coverage   84.55%   84.21%   -0.34%     
==========================================
  Files        1117     1118       +1     
  Lines      202684   203013     +329     
==========================================
- Hits       171370   170969     -401     
- Misses      31314    32044     +730     

[fengjiachun]

Rest LGTM

[killme2008]

Why not implement it? It's very useful for both standalone and distributed clusters to get the statistics info of regions.

[fengjiachun]

I have implemented it in #4811