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| 1 | +--- |
| 2 | +title: Redis 8.2 |
| 3 | +alwaysopen: false |
| 4 | +categories: |
| 5 | +- docs |
| 6 | +- operate |
| 7 | +- rs |
| 8 | +- rc |
| 9 | +description: What's new in Redis 8.2 |
| 10 | +linkTitle: What's new in Redis 8.2 |
| 11 | +weight: 4 |
| 12 | +--- |
| 13 | + |
| 14 | +Redis 8.2 builds on the foundation of Redis 8.0 with significant performance and memory optimizations, enhanced streaming capabilities, and improved cluster management tools. |
| 15 | + |
| 16 | +This release delivers major improvements across multiple areas: |
| 17 | +- Enhanced Redis Streams with new commands for better consumer group management |
| 18 | +- Advanced cluster monitoring with per-slot usage metrics |
| 19 | +- Optimized vector search with new compression algorithms |
| 20 | +- Substantial performance gains across core operations |
| 21 | + |
| 22 | +Below is a detailed breakdown of these updates. |
| 23 | + |
| 24 | +## New features |
| 25 | + |
| 26 | +### Enhanced Redis Streams |
| 27 | +Redis 8.2 introduces powerful new commands that simplify consumer group management and stream lifecycle operations: |
| 28 | + |
| 29 | +- [XDELEX](https://redis.io/docs/latest/commands/xdelex/): Delete entries from streams with advanced consumer group handling options |
| 30 | +- [XACKDEL](https://redis.io/docs/latest/commands/xackdel/): Acknowledge and delete stream entries in a single atomic operation |
| 31 | + |
| 32 | +These commands include `KEEPREF`, `DELREF`, and `ACKED` options that give you precise control over how consumer group references are handled during entry deletion. This simplifies common patterns where you need to clean up acknowledged entries while maintaining consumer group integrity. |
| 33 | + |
| 34 | +The `XADD` and `XTRIM` commands have also been extended with these same options, providing consistent behavior across all stream management operations. |
| 35 | + |
| 36 | +### Cluster monitoring improvements |
| 37 | +The new [CLUSTER SLOT-STATS](https://redis.io/docs/latest/commands/cluster-slot-stats/) command provides detailed per-slot usage metrics including: |
| 38 | +- Key count per slot |
| 39 | +- CPU time consumption |
| 40 | +- Network I/O statistics |
| 41 | + |
| 42 | +This enhanced visibility helps you optimize cluster performance and identify hotspots in your data distribution. |
| 43 | + |
| 44 | +### Vector search enhancements |
| 45 | +Redis 8.2 introduces the SVS-VAMANA vector index type, which supports vector compression and is optimized for Intel machines. This new index type can significantly reduce memory usage while maintaining search performance for vector similarity operations. |
| 46 | + |
| 47 | +The `VSIM` command now supports the `IN` operator for filtering expressions, giving you more flexibility when performing vector similarity searches with complex filtering criteria. |
| 48 | + |
| 49 | +## Improvements |
| 50 | + |
| 51 | +### Performance optimizations |
| 52 | +Redis 8.2 delivers substantial performance improvements across core operations: |
| 53 | + |
| 54 | +- **BITCOUNT**: Enhanced with prefetching optimizations for faster bit counting operations |
| 55 | +- **SCAN**: Optimized to perform expiration checks only on databases with volatile keys, reducing unnecessary overhead |
| 56 | +- **List operations**: `LREM`, `LPOS`, and `LINSERT` benefit from cached `string2ll` results in `quicklistCompare` |
| 57 | +- **Sorted set operations**: `ZRANK` and related commands use the same caching optimizations |
| 58 | +- **Key operations**: `COPY`, `RENAME`, and `RESTORE` are optimized when TTL is used |
| 59 | +- **Client management**: Reduced overhead in client cron operations to avoid blocking the main thread |
| 60 | + |
| 61 | +### Memory efficiency improvements |
| 62 | +- **JSON data types**: Memory footprint improvements through number inlining |
| 63 | +- **Memory tracking**: Reduced overhead associated with tracking malloc's usable memory |
| 64 | +- **Expiry handling**: Optimized expiry checks in scan callbacks |
| 65 | + |
| 66 | +### Enhanced metrics |
| 67 | +Redis 8.2 provides new metrics to help you monitor and troubleshoot your Redis instances: |
| 68 | + |
| 69 | +#### Memory metrics |
| 70 | +- `used_memory_peak_time`: Timestamp when `used_memory_peak` was reached |
| 71 | + |
| 72 | +#### Replication metrics |
| 73 | +- `master_current_sync_attempts`: Number of sync attempts since last disconnection |
| 74 | +- `master_total_sync_attempts`: Total number of sync attempts to master |
| 75 | +- `master_link_up_since_seconds`: Duration since the replication link was established |
| 76 | +- `total_disconnect_time_sec`: Cumulative time the replica has been disconnected |
| 77 | + |
| 78 | +These metrics provide better visibility into replication health and help you identify patterns in connection stability. |
| 79 | + |
| 80 | +## Security improvements |
| 81 | +Redis 8.2 includes important security fixes: |
| 82 | +- **CVE-2025-27151**: Fixed potential stack overflow and RCE vulnerability in redis-check-aof |
| 83 | + |
| 84 | +## Component versions |
| 85 | +Redis 8.2 continues the unified distribution approach introduced in Redis 8.0, delivering all functionality in a single Redis Open Source package without separate modules. |
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