v2.5.8

## v2.5.8

Release date: April 1, 2025

| Milvus version | Python SDK version | Node.js SDK version | Java SDK version |
|----------------|--------------------|---------------------|------------------|
| 2.5.8          | 2.5.6              | 2.5.7               | 2.5.6            |

We’re excited to announce the release of Milvus 2.5.8, featuring enhancements to JSON expressions, UTF-8 validation, memory usage, and balancing logic. This version also includes multiple important bug fixes to improve concurrency and data handling. We encourage you to upgrade or give it a try, and as always, your feedback helps us continually refine Milvus!

### Improvements

- Support JSON `null`/`exists` expressions ([#41002](https://github.com/milvus-io/milvus/pull/41002))
- Balance the collection with the largest row count first ([#40958](https://github.com/milvus-io/milvus/pull/40958))
- Support parsing sparse vectors from Parquet structs in bulk inserts ([#40874](https://github.com/milvus-io/milvus/pull/40874))
- Support UTF-8 string validation during import ([#40746](https://github.com/milvus-io/milvus/pull/40746))
- Add UTF-8 validation for all VARCHAR fields ([#40993](https://github.com/milvus-io/milvus/pull/40993))
- Avoid re-query if hybrid search only requests the PK as output field ([#40906](https://github.com/milvus-io/milvus/pull/40906))
- Refine array views to optimize memory usage ([#40206](https://github.com/milvus-io/milvus/pull/40206))
- Add a trigger interval configuration for auto-balancing ([#39918](https://github.com/milvus-io/milvus/pull/39918))
- Convert multiple OR expressions to IN expression ([#40751](https://github.com/milvus-io/milvus/pull/40751))
- Support detailed manual compaction criteria ([#40924](https://github.com/milvus-io/milvus/pull/40924))
- Retain raw tokens for audit logging ([#40867](https://github.com/milvus-io/milvus/pull/40867))
- Optimize DataCoord meta mutex usage ([#40753](https://github.com/milvus-io/milvus/pull/40753))
- Introduce batch subscriptions in `MsgDispatcher` ([#40596](https://github.com/milvus-io/milvus/pull/40596))

### Bug fixes

- Fixed a crash involving nullable input and growing mmap data types ([#40980](https://github.com/milvus-io/milvus/pull/40980))
- Fixed potential data loss in delete operations caused by duplicate binlog IDs ([#40985](https://github.com/milvus-io/milvus/pull/40985)), ([#40976](https://github.com/milvus-io/milvus/pull/40976))
- Added field index locks for `GetSegmentsIndexStates` to avoid potential panic when insertion while creating collection ([#40969](https://github.com/milvus-io/milvus/pull/40969))
- Fixed concurrency issues in Rocksmq consumer registration ([#40885](https://github.com/milvus-io/milvus/pull/40885))
- Retrieve all child delta logs for segment loading ([#40957](https://github.com/milvus-io/milvus/pull/40957))
- Fixed wrong results caused by using JSON index when `iterative_filter` is specified ([#40946](https://github.com/milvus-io/milvus/pull/40946))
- Ensured higher priority for the `exists` operation ([#40865](https://github.com/milvus-io/milvus/pull/40865))
- Corrected `WithGroupSize` while reducing ([#40920](https://github.com/milvus-io/milvus/pull/40920))
- Increased the number of slots proportionally as segment size grows ([#40862](https://github.com/milvus-io/milvus/pull/40862))
- Set task queue time before enqueue ([#40853](https://github.com/milvus-io/milvus/pull/40853))
- Fixed channel imbalance on DataNodes ([#40854](https://github.com/milvus-io/milvus/pull/40854))
- Set correct default configurations for task slots ([#40821](https://github.com/milvus-io/milvus/pull/40821))
- Go SDK: Set nullable flags according to FieldSchema for row-based insert ([#40962](https://github.com/milvus-io/milvus/pull/40962))