Redis Open Source 8.2 release notes

Redis Open Source 8.2 release notes.

Redis Open Source 8.2.1 (August 2025)

Update urgency: MODERATE: Program an upgrade of the server, but it's not urgent.

Bug fixes

• #14240 INFO KEYSIZES - potential incorrect histogram updates on cluster mode with modules.
• #14274 Disable Active Defrag during flushing replica.
• #14276 XADD or XTRIM can crash the server after loading RDB.
• #Q6601 Potential crash when running FLUSHDB (MOD-10681).

Performance and resource utilization

• Query Engine - LeanVec and LVQ proprietary Intel optimizations were removed from Redis Open Source.
• #Q6621 Fix regression in INFO (MOD-10779).

Redis Open Source 8.2 (August 2025)

This is the General Availability release of Redis 8.2 in Redis Open Source.

Headlines

Redis 8.2 introduces major performance and memory footprint improvements, new commands, and command extensions.

Major changes compared to 8.0

• Streams - new commands: XDELEX and XACKDEL; extension to XADD and XTRIM.
• Bitmap - BITOP: new operators: DIFF, DIFF1, ANDOR, and ONE.
• Query Engine - new SVS-VAMANA vector index type which supports vector compression.
• More than 15 performance and resource utilization improvements.
• New metrics: per-slot usage metrics, key size distributions for basic data types, and more.

Binary distributions

• Alpine and Debian Docker images - https://hub.docker.com/_/redis
• Install using snap - see https://github.com/redis/redis-snap
• Install using brew - see https://github.com/redis/homebrew-redis
• Install using RPM - see https://github.com/redis/redis-rpm
• Install using Debian APT - see https://github.com/redis/redis-debian

Redis 8.0.0 was tested on the following operating systems

• Ubuntu 22.04 (Jammy Jellyfish), 24.04 (Noble Numbat)
• Rocky Linux 8.10, 9.5
• AlmaLinux 8.10, 9.5
• Debian 12 (Bookworm)
• macOS 13 (Ventura), 14 (Sonoma), 15 (Sequoia)

Security fixes (compared to 8.2-RC1)

• (CVE-2025-32023) Fix out-of-bounds write in HyperLogLog commands.
• (CVE-2025-48367) Retry accepting other connections even if the accepted connection reports an error.

New Features (compared to 8.2-RC1)

• #14141 Keyspace notifications - new event types:
  • OVERWRITTEN - the value of a key is completely overwritten
  • TYPE_CHANGED - key type change

Bug fixes (compared to 8.2-RC1)

• #14162 Crash when using evport with I/O threads.
• #14163 EVAL crash when error table is empty.
• #14144 Vector sets - RDB format is not compatible with big endian machines.
• #14165 Endless client blocking for blocking commands.
• #14164 Prevent CLIENT UNBLOCK from unblocking CLIENT PAUSE.
• #14216 TTL was not removed by the SET command.
• #14224 HINCRBYFLOAT removes field expiration on replica.

Performance and resource utilization improvements (compared to 8.2-RC1)

• #Q6430 More compression variants for the SVS-VAMANA vector index.
• #Q6535 SHARD_K_RATIO parameter - favor network latency over accuracy for KNN vector query in a Redis cluster (unstable feature) (MOD-10359).
• #14144 Vector set - improve RDB loading / RESTORE speed by storing the worst link info .

Modules API

• #14051 RedisModule_Get*, RedisModule_Set* - allow modules to access Redis configurations.
• #14114 RM_UnsubscribeFromKeyspaceEvents - unregister a module from specific keyspace notifications.

Redis Open Source 8.2-RC1 (July 2025)

This is the first Release Candidate of Redis Open Source 8.2.

Release Candidates are feature-complete pre-releases. Pre-releases are not suitable for production use.

Headlines

Redis 8.2 introduces major performance and memory footprint improvements, new commands, and command extensions.

Redis 8.2-RC1 is available as a Docker image and can be downloaded from Docker Hub. Additional distributions will be introduced in upcoming pre-releases.

Security fixes (compared to 8.2-M01)

• (CVE-2025-27151) redis-check-aof may lead to stack overflow and potential RCE

New Features (compared to 8.2-M01)

• #14130 Streams - new commands: XDELEX and XACKDEL; extension to XADD and XTRIM.
• #14039 New command: CLUSTER SLOT-STATS - get per-slot usage metrics such as key count, CPU time, and network I/O.
• #14122 VSIM - new IN operator for filtering expressions.
• #Q6329, #Q6394 - Query Engine - new SVS-VAMANA vector index type which supports vector compression (optimized for Intel machines).

Bug fixes (compared to 8.2-M01)

• #14143 Gracefully handle short read errors for hashes with TTL during full sync.

Performance and resource utilization improvements (compared to 8.2-M01)

• #14103 Optimize BITCOUNT by introducing prefetching.
• #14121 Optimize SCAN by performing expiration checks only on DBs with volatile keys.
• #14140 Optimize expiry check in scanCallback.
• #14131 Optimize LREM, LPOS, LINSERT, ZRANK, and more by caching string2ll results in quicklistCompare.
• #14088 Optimize COPY, RENAME, and RESTORE when TTL is used.
• #14074 Reduce the overhead associated with tracking malloc’s usable memory.
• #13900 Optimize the client’s cron to avoid blocking the main thread.
• #J1350 JSON - memory footprint improvement by inlining numbers (MOD-9511).

Metrics

• #14067 INFO: used_memory_peak_time - time when used_memory_peak was hit.
• #13990 INFO:
  • master_current_sync_attempts - number of times the replica attempted to sync to a master since last disconnection.
  • master_total_sync_attempts - number of times the replica attempted to sync to a master.
  • master_link_up_since_seconds - number of seconds since the link has been up.
  • total_disconnect_time_sec - total cumulative time the replica has been disconnected.