Redis Open Source 8.6 release notes

Redis Open Source 8.6 release notes.

Redis Open Source 8.6.0 (February 2026)

This is the General Availability release of Redis 8.6 in Redis Open Source.

Major changes compared to 8.4

• Substantial performance improvements.
• Substantial memory reduction for hashes (hashtable-encoded) and sorted sets (skiplist-encoded).
• Streams: XADD idempotency (at-most-once guarantee) with new IDMPAUTO and IDMP arguments.
• New eviction policies - least recently modified: volatile-lrm and allkeys-lrm.
• Hot keys detection and reporting; new command: HOTKEYS.
• TLS certificate-based automatic client authentication.
• Time series: support NaN values; new aggregators: COUNTNAN and COUNTALL.

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

Operating systems we test Redis 8.6 on

• Ubuntu 22.04 (Jammy Jellyfish), 24.04 (Noble Numbat)
• Rocky Linux 8.10, 9.5
• AlmaLinux 8.10, 9.5, 10.1
• Debian 12 (Bookworm), Debian 13 (Trixie)
• macOS 14 (Sonoma), 15 (Sequoia)

New Features (compared to 8.6-RC1)

• #14695 Keys memory size histograms.

Performance and resource utilization improvements (compared to 8.6-RC1)

• #14714 Optimize user ACL permission verification.
• #14692 Optimize peak memory metric collection.
• #14739 Avoid allocating and releasing list node in reply copy avoidance.
• #14713 Reduce per command syscalls by reusing cached time when hardware monotonic clock is available.
• #14726 Optimize XREADGROUP CLAIM.
• #13962 Vector set: replace manual popcount with __builtin_popcountll for binary vector distance (Intel, AMD, ARM).
• #14474 Vector set: vectorized the quantized 8-bit vector distance calculation (Intel, AMD).
• #14492 Vector set: vectorize binary quantization path for vectorsets distance calculation (Intel, AMD).

Configuration parameters

• #14719 cluster-slot-stats-enabled - per-slot resource consumptions statistics to collect.
• #14695 key-memory-histograms collect memory consumption histograms per data type.

Metrics

• #14695 db0_distrib_lists_sizes, db0_distrib_sets_sizes, db0_distrib_hashes_sizes, db0_distrib_zsets_sizes.

Known bugs and limitations

• Streams: avoid using XADD with the new IDMP or IDMPAUTO options when using appendonly yes with aof-use-rdb-preamble no (non default). This limitation will be removed in the next patch.

Redis Open Source 8.6-RC1 (January 2026)

This is the first Release Candidate of Redis 8.6 in Redis Open Source.

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

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

Operating systems we test Redis 8.6 on

• Ubuntu 22.04 (Jammy Jellyfish), 24.04 (Noble Numbat)
• Rocky Linux 8.10, 9.5, 10.1
• AlmaLinux 8.10, 9.5, 10.1
• Debian 12 (Bookworm), Debian 13 (Trixie)
• 14 (Sonoma), 15 (Sequoia)

New Features (compared to 8.4.0)

• #14615 Streams: XADD idempotency (at-most-once guarantee) with new IDMPAUTO and IDMP arguments.
• #14624 New eviction policies - least recently modified: volatile-lrm and allkeys-lrm.
• #14680 Hot keys detection and reporting; new command: HOTKEYS.
• #14610 TLS certificate-based automatic client authentication.
• RedisTimeSeries/RedisTimeSeries#1853 Time series: support NaN values; new aggregators: COUNTNAN and COUNTALL.

Security and privacy fixes

• #14645 Hide personally identifiable information from ACL log.
• #14659 ACL: Key-pattern bypass in MSETEX.
• RedisTimeSeries/RedisTimeSeries#1837, RedisJSON/RedisJSON#1474 Hide personally identifiable information from server log.
• RedisBloom/RedisBloom#950 Out-of-bounds read when loading an invalid RDB file (MOD-12802).

Bug fixes (compared to 8.4.0)

• #14545 ACL: AOF loading fails if ACL rules are changed and don't allow some commands in MULTI-EXEC.
• #14637 Atomic slot migration: wrong adjacent slot range behavior.
• #14567 Atomic slot migration: support delay trimming slots after finishing migrating slots.
• #14623 Streams: XTRIM/XADD with approx mode (~) don’t delete entries for DELREF/ACKED strategies.
• #14552 Streams: Incorrect behavior when using XDELEX...ACKED after XGROUP DESTROY.
• #14537 SCAN: restore original filter order (revert change introduced in 8.2).
• #14581 Rare server hang at shutdown.
• #14597 Panic when cluster node is uninitialized.
• #14583 FLUSHALL ASYNC on a writable replica may block the main thread for an extended period.
• #14504 Cluster: fix race condition in broadcast configuration.
• #14416 Fixed argument position handling in Redis APIs.
• RedisTimeSeries/RedisTimeSeries#1784, RedisTimeSeries/RedisTimeSeries#1839, RedisBloom/RedisBloom#952, RedisJSON/RedisJSON#1477 Atomic slot migration support.
• RedisBloom/RedisBloom#946 MEMORY USAGE: fix reported value (MOD-12799).
• RedisJSON/RedisJSON#1473 Adding escapes to already-escaped characters (MOD-8137).
• RedisJSON/RedisJSON#1475 JSON.CLEAR does not error if more than one path is specified (MOD-13109).

Performance and resource utilization improvements (compared to 8.4.0)

• #14608 Reply copy-avoidance path to reduce memory copies for bulk string replies.
• #14595 Hash: unify field name and value into a single struct.
• #14701 Sorted set: unify score and value into a single struct.
• #14662 Optimize listpack iterator on hash fields.
• #14699 Optimize set commands with expiration.
• #14700 Optimize prefetching.
• #14715 Optimize prefetch sizing logic.
• #14636 Optimize ZRANK.
• #14676 Utilize hardware clock by default on ARM AArch64.
• #14575 Disable RDB compression when diskless replication is used.

Modules API

• #14445
  • RM_CreateKeyMetaClass - define a new key-metadata class.
  • RM_ReleaseKeyMetaClass - release a key-metadata class.
  • RM_SetKeyMeta - attach or update a metadata value for a key under a specific metadata-key class.
  • RM_GetKeyMeta - get a metadata value for a key under a specific metadata-key class.

Configuration parameters

• #14624 maxmemory-policy: new eviction policies: volatile-lrm, allkeys-lrm.
• #14615 stream-idmp-duration, stream-idmp-maxsize - defaults for streams idempotent production.
• #14610 tls-auth-clients-user TLS certificate-based automatic client authentication.
• #14596 flushdb option for repl-diskless-load: always flush the entire dataset before diskless load.

Metrics

• #14610 acl_access_denied_tls_cert - failed TLS certificate–based authentication attempts.

Known bugs and limitations

• Redis Query Engine: In case of load rebalancing operations (such as Atomic Slot Migration) taking place during the lifetime of a cursor, there is a chance that some results may be missing.