v2.3.21

## v2.3.21

Release data: August 14, 2024

| Milvus version | Python SDK version | Java SDK version | Go SDK version | Node.js SDK version |
|----------------|--------------------|------------------|----------------|---------------------|
| 2.3.21         | 2.3.7              | 2.3.6            | 2.3.6          | 2.3.5               |

Miluvs v2.3.21 addresses a critical bug in data deletion ([#35390](https://github.com/milvus-io/milvus/pull/35390)) and introduces some improvements in metrics and performance.

### Improvements

- Enhanced data deletion process by modifying the delegator's delete buffer handling  ([#35074](https://github.com/milvus-io/milvus/pull/35074))
- Added metrics to track disk quota usage  ([#35320](https://github.com/milvus-io/milvus/pull/35320))
- Reduced delegator memory usage by adjusting the overloaded factor to 0.1  ([#35165](https://github.com/milvus-io/milvus/pull/35165))
- Improved health check by skipping manually stopped components ([#35122](https://github.com/milvus-io/milvus/pull/35122))
- Added metric to record maxinsertrate and querynodememoryhighwaterlevel  ([#35193](https://github.com/milvus-io/milvus/pull/35193))
- Upgraded the Conan version ([#35217](https://github.com/milvus-io/milvus/pull/35217))
- Changed the default metric type for autoindex ([#34328](https://github.com/milvus-io/milvus/pull/34328))
- Sped up the datacoord gc quit process ([#35057](https://github.com/milvus-io/milvus/pull/35057))
- Avoided panic due to nil schema  ([#35065](https://github.com/milvus-io/milvus/pull/35065))
- Reduced duplicate primary keys in the segcore component  ([#35291](https://github.com/milvus-io/milvus/pull/35291))
- Tracked the number of times Milvus enters a force-deny-writing state ([#34990](https://github.com/milvus-io/milvus/pull/34990))

### Bug fixes

- Resolved an issue with the BloomFilter returning false negatives when the statslog contained multiple K values, which could occur when a delete operation failed to apply ([#35390](https://github.com/milvus-io/milvus/pull/35390))
- Enabled a limiter for RESTful server ([#35354](https://github.com/milvus-io/milvus/pull/35354))
- Added a retry mechanism to avoid getting incomplete query results ([#35061](https://github.com/milvus-io/milvus/pull/35061))
- Fixed issues with delete-by-expression operations failing during retry progress  ([#35421](https://github.com/milvus-io/milvus/pull/35421))
- Addressed a problem where the datanode binlog size metrics included dropped segments  ([#35420](https://github.com/milvus-io/milvus/pull/35420))
- Resolved comparison operations between incompatible operands  ([#35308](https://github.com/milvus-io/milvus/pull/35308))
- Fixed an issue where the datanode could not watch the channel ([#35136](https://github.com/milvus-io/milvus/pull/35136))
- Addressed a deadlock issue on compaction when stopping the datanode ([#35199](https://github.com/milvus-io/milvus/pull/35199))