Redis Knowledge Patch

Redis Knowledge Patch

Use this skill when upgrading, securing, configuring, or developing against Redis Open Source. Start with release and topology discovery, check the security floor and ACL implications, and then open the reference for the affected command family or operational task.

Reference index

Working method

1. Identify the exact Redis release, deployment topology, persistence mode, and enabled components before applying version-sensitive advice.
2. Check the security floor for the deployed minor line. Do not treat the patch number from a different minor line as an equivalent fix.
3. Re-audit ACL rules when moving from standalone modules or Redis Stack to integrated Redis components.
4. Check persistence and cluster caveats before enabling stream idempotency, backup workflows, or slot migration.
5. Open the topic reference before implementing an affected command. It holds maintenance-release floors and restrictions omitted from this quick view.

Breaking, security, and compatibility checks

Patch security-sensitive deployments first

Choose a fixed release from the deployed minor line. Important minimums include:

The five-path RCE group spans client unblock, RESTORE, Lua, Time Series, and probabilistic structures. The 8.10.1 group includes CMSketch RDB loading, TopK cleanup, the TLS pending-data list, SLOT_INFO RDB loading, three Vector Set paths, blocked-client reprocessing, and an embedded-NUL certificate bypass.

Account for integrated components

Search, JSON, Time Series, Bloom, Cuckoo, Count-min sketch, Top-k, and t-digest are integral components beginning in Redis 8. Binary distributions include them, redis-full.conf loads them all, and Vector Set is preview functionality.

Replication and persistence upgrades can start from module-free Redis, Redis using the former standalone modules, or Redis Stack 7.2 or 7.4. Plan component packaging and ACL changes as part of the same migration.

Re-audit ACLs

Broad categories such as @read and @write include commands from the integrated components. Replace unintended broad grants with narrower @search, @json, @timeseries, @bloom, @cuckoo, @cms, @topk, and @tdigest rules.

Search index access also depends on key patterns: a user's patterns must cover a superset of the index prefixes. Multi-key Time Series reads fail if any matching key is unreadable, while TS.QUERYINDEX reads metadata without requiring read access to those keys.

Remove obsolete vector assumptions

The proprietary LeanVec and LVQ Intel optimizations are absent from Redis Open Source starting in 8.2.1. Redis 8.2 provides compressed SVS-VAMANA; 8.2.2 allows the BUILD_INTEL_SVS_OPT build flag for Intel optimizations.

Respect persistence and migration caveats

XADD IDMPAUTO and IDMP arrived in Redis 8.6. Redis 8.6.0 warns against combining them with appendonly yes and aof-use-rdb-preamble no; Redis 8.6.2 fixes AOF rewrite and restoration of idempotency state.

CLUSTER MIGRATION moves slots atomically, but affected Search and Time Series multi-key queries can still return partial or duplicate results while a migration is in progress.

High-value command changes

Strings, counters, hashes, and sets

• DIGEST, DELEX, and SET extensions support atomic compare-and-set and compare-and-delete flows on strings.
• MSETEX atomically writes multiple string keys and updates expiration.
• INCREX combines integer or floating-point increments, bounds, and expiration for window-counter rate limiting.
• Compact hashes share field names among keys with the same schema; HIMPORT provides high-throughput bulk insertion for that encoding.
• SUNIONCARD and SDIFFCARD return union and difference cardinalities.

Lists and streams

• LMOVEM and blocking BLMOVEM move multiple list elements.
• XDELEX, XACKDEL, and extensions to XADD and XTRIM add DELREF and ACKED deletion-reference strategies.
• XREADGROUP CLAIM min-idle-time combines sufficiently idle pending entries and incoming entries in one read.
• XADD IDMPAUTO and IDMP provide at-most-once production; stream-idmp-duration and stream-idmp-maxsize supply defaults.
• XNACK lets a consumer explicitly release pending messages.
• XREAD and XREADGROUP accept MAXCOUNT and MAXSIZE reply bounds.

Core structures and notifications

• Array is a Redis data structure.
• BITOP supports DIFF, DIFF1, ANDOR, and ONE.
• ZUNION, ZINTER, ZUNIONSTORE, and ZINTERSTORE accept the COUNT aggregator.
• OVERWRITTEN reports full replacement, TYPE_CHANGED reports a type change, and hash subkey notifications emit field-level events.
• Replicated CF.LOADCHUNK chunks prevent silent Cuckoo Filter loss after failover on fixed maintenance releases.

Search, JSON, and Time Series

Vector and hybrid Search

• VSIM WITHATTRIBS returns an element's JSON attribute; EPSILON supplies a maximum distance.
• FT.HYBRID combines result sets with RRF or LINEAR scoring.
• In the original Redis 8.4 behavior, filtering after COMBINE is unavailable, the default response contains only key_id and score, and EXPLAINSCORE, YIELD_DISTANCE_AS, and WITHCURSOR are unsupported.
• A newer KNN argument requests fewer candidates per shard, and FT.PROFILE HYBRID profiles hybrid queries.
• search-default-scorer sets the default text and tag scorer; BM25STD is the new default.
• FT.ALIASLIST enumerates index aliases, and Search supports Malay and Tagalog stemming.
• FT.CREATE and FT.ALTER reject empty field names.

JSON and Time Series

• JSON.SET FPHA selects the floating-point type for a homogeneous floating-point array.
• TS.RANGE, TS.REVRANGE, TS.MRANGE, and TS.MREVRANGE can apply multiple aggregators in one command.
• Time Series accepts NaN and provides COUNTNAN and COUNTALL.
• TS.NRANGE and TS.NREVRANGE query multiple series grouped by timestamp.
• TS.READ optionally blocks while reading from time series.
• TS.QUERYLABELS discovers labels and their values.
• TS.MRANGE and TS.MREVRANGE EXCLUDEEMPTY omit series with no samples.

Operations quick reference

• Runtime memory tracking can be enabled only in non-clustered mode.
• volatile-lrm and allkeys-lrm select least-recently-modified eviction.
• HOTKEYS detects hot keys; HOTKEYS HELP is available from 8.6.1.
• INFO KEYSIZES reports size distributions for basic data types.
• CLUSTER SLOT-STATS reports per-slot key count, CPU time, and network I/O.
• key-memory-histograms collects per-type histograms and exposes database distribution metrics for lists, sets, hashes, and sorted sets.
• BACKUP performs node-side backup and restore using multi-part AOF.
• Modules can read and write Redis configuration and selectively unsubscribe from keyspace notifications.
• tls-auth-clients-user maps client certificates to a user; failed attempts increment acl_access_denied_tls_cert.
• Server-to-server TLS connections can authenticate peers by certificate.

Read the indexed reference before implementing any affected behavior. The references preserve exact maintenance floors, ACL boundaries, persistence warnings, topology restrictions, and command-specific constraints.