redis cheat sheet 7.x / 8.x

• redis-cli★
  Connect to localhost:6379.
• redis-cli -h host -p 6380 -a pass★
  Remote host, port, password.
• redis-cli -n 2
  Select logical DB 2 (0-15 by default).
• redis-cli --tls -u rediss://user:pw@host:6379
  TLS connection via URI.
• HELLO 3★
  Switch to RESP3 protocol (7.0+) — maps, push, etc.
• PING · ECHO "hi" · SELECT 0
  Liveness, echo, switch DB.
• redis-cli --scan --pattern "user:*"
  Safely stream matching keys.

• EXISTS key · TYPE key★
  Presence; value's data type.
• DEL k1 k2 · UNLINK k★
  Delete now / async (non-blocking) delete.
• RENAME k newk · COPY k k2
  Rename / copy a key (COPY 6.2+).
• SCAN 0 MATCH "user:*" COUNT 100★
  Cursor iteration — use instead of KEYS in prod.
• OBJECT ENCODING key★
  Internal encoding (7.0: listpack replaces ziplist).
• OBJECT FREQ / IDLETIME key
  LFU frequency / idle seconds for eviction insight.
• RANDOMKEY · DBSIZE
  Random key; total key count.

• EXPIRE key 60 · PEXPIRE key 60000★
  Expire in seconds / milliseconds.
• EXPIRE key 60 NX|XX|GT|LT★
  Conditional expire (7.0+): only if no TTL / greater / less.
• TTL key · PTTL key★
  Remaining life; -1 no expiry, -2 gone.
• EXPIRETIME key · PEXPIRETIME key
  Absolute Unix expiry time (7.0+).
• EXPIREAT key 1893456000
  Expire at an absolute timestamp.
• PERSIST key★
  Remove the TTL, make the key permanent.

• SET k v · GET k★
  Basic write / read.
• SET k v EX 60 NX★
  TTL + only-if-absent (lock pattern).
• SET k v NX GET
  7.0+ — set-if-absent and return the old value.
• SET k v KEEPTTL
  Overwrite value but preserve the existing TTL.
• INCR k · INCRBY k 5 · INCRBYFLOAT k 1.5★
  Atomic counters.
• MSET k1 v1 k2 v2 · MGET k1 k2★
  Multi-key set / get in one round-trip.
• APPEND k v · STRLEN k · GETRANGE k 0 4
  Append; length; substring.
• GETDEL k · GETEX k EX 30
  Get-and-delete / get-and-set-TTL (6.2+).

• LPUSH k v · RPUSH k v★
  Prepend / append elements.
• LPOP k [count] · RPOP k★
  Pop from head / tail.
• LRANGE k 0 -1★
  Range by index; -1 is the last element.
• LLEN k · LINDEX k 0 · LSET k 0 v
  Length; get / set by index.
• BLPOP k 5 · BRPOP k 5★
  Blocking pop — wait up to N seconds.
• LMOVE src dst LEFT RIGHT
  Atomic transfer between lists (reliable queues).
• LTRIM k 0 99 · LREM k 1 v
  Keep a window; remove occurrences.

• HSET k field v [f2 v2]★
  Set one or many fields.
• HGET k field · HMGET k f1 f2★
  Get one / several fields.
• HGETALL k★
  All field/value pairs (RESP3 returns a map).
• HDEL k field · HEXISTS k f
  Delete field; test presence.
• HINCRBY k field 1★
  Atomic per-field counter.
• HKEYS k · HVALS k · HLEN k · HSCAN k 0
  Fields, values, count, cursor scan.
• HGETEX k FIELDS 1 f · HGETDEL k ...
  8.0 — get with TTL option / get-and-delete fields.

• HEXPIRE k 60 FIELDS 1 field★
  Expire a single hash field in N seconds.
• HPEXPIRE k 500 FIELDS 1 field
  Millisecond precision.
• HEXPIREAT k 1893456000 FIELDS 1 f
  Expire a field at an absolute time.
• HTTL k FIELDS 1 field★
  Remaining TTL per field; HPTTL for ms.
• HEXPIRETIME k FIELDS 1 f
  Absolute expiry timestamp of a field.
• HPERSIST k FIELDS 1 field
  Remove a field's TTL — huge for session stores.

• SADD k m · SREM k m★
  Add / remove members.
• SISMEMBER k m · SMISMEMBER k m1 m2★
  Membership test (SMISMEMBER 6.2+).
• SMEMBERS k · SCARD k★
  All members; cardinality.
• SINTER k1 k2 · SUNION · SDIFF★
  Intersection / union / difference.
• SINTERCARD 2 k1 k2 LIMIT 10★
  7.0+ — size of intersection without materializing it.
• SRANDMEMBER k 3 · SPOP k
  Random members / pop a random member.

• ZADD k 100 m★
  Add member with a score; GT/LT/NX modifiers.
• ZRANGE k 0 -1 [REV] [WITHSCORES]★
  By rank; unified ranges (6.2+ replaces ZREVRANGE).
• ZRANGEBYSCORE k 10 50 · ZRANGEBYLEX
  By score / lexicographic range.
• ZRANK k m [WITHSCORE] · ZSCORE k m★
  Position / score of a member.
• ZINCRBY k 5 m · ZCARD k · ZCOUNT k 0 100
  Bump score; count total / within range.
• ZINTERCARD 2 k1 k2 · ZDIFF · ZUNION
  7.0+ intersect-cardinality; set-style ops (6.2+).
• ZPOPMIN k · ZPOPMAX k · BZPOPMIN k 5
  Pop lowest / highest; blocking variant.

• LMPOP 2 q1 q2 LEFT [COUNT 3]★
  Pop from the first non-empty list among many.
• BLMPOP 5 2 q1 q2 LEFT★
  Blocking multi-list pop — priority queues.
• ZMPOP 2 z1 z2 MIN
  Pop from the first non-empty sorted set.
• BZMPOP 5 2 z1 z2 MIN
  Blocking sorted-set multi-pop.
• // cleaner than chaining BRPOP per queue
  One command spans several keys with a priority order.

• SETBIT k 7 1 · GETBIT k 7★
  Flip / read a single bit — presence flags.
• BITCOUNT k [0 0 BIT]★
  Count set bits; 7.0 adds BIT-index ranges.
• BITPOS k 1 [0 -1 BIT]
  First set/clear bit; BIT ranges (7.0+).
• BITOP AND|OR|XOR|NOT dst k1 k2★
  Bitwise ops; 8.2 adds DIFF/DIFF1/ANDOR/ONE.
• BITFIELD k INCRBY u8 0 1 GET u8 0
  Packed integer fields inside one string.
• PFADD k m · PFCOUNT k · PFMERGE d k1 k2★
  HyperLogLog — ~unique count in 12KB, 0.81% error.

• XADD k * field v★
  Append an entry; * auto-generates the ID.
• XADD k MAXLEN ~ 1000 * ...★
  Append and cap length (~ = approximate trim).
• XLEN k · XRANGE k - + · XREVRANGE★
  Length; range scan of entries.
• XREAD BLOCK 0 STREAMS k $★
  Tail new entries, blocking.
• XGROUP CREATE k grp $★
  Create a consumer group.
• XREADGROUP GROUP grp c COUNT 10 STREAMS k >★
  Read as a group; > = never-delivered.
• XACK k grp id · XPENDING · XCLAIM
  Acknowledge; inspect / reclaim pending entries.
• XDELEX k ... · XACKDEL k ...
  8.0 — delete-with-condition / ack-and-delete.

• GEOADD k lng lat name★
  Store a point (lon, lat, member).
• GEOSEARCH k FROMMEMBER x BYRADIUS 5 km ASC★
  6.2+ unified radius/box search (replaces GEORADIUS).
• GEOSEARCH k FROMLONLAT x y BYBOX 10 10 km
  Rectangular area search.
• GEODIST k a b km★
  Distance between two members.
• GEOPOS k name · GEOHASH k name
  Coordinates / geohash string of a member.
• GEOSEARCHSTORE dst k ...
  Store search results into another key.

• MULTI … EXEC★
  Queue commands, run atomically as a unit.
• DISCARD
  Abort a queued transaction.
• WATCH key★
  Optimistic lock — EXEC aborts if the key changed.
• UNWATCH
  Forget all watched keys.
• // no rollback — queued errors still run others
  Redis txns are atomic, not rollback-based.

• SUBSCRIBE channel · PUBLISH channel msg★
  Classic broadcast to all subscribers.
• PSUBSCRIBE "news.*"★
  Pattern subscription across channels.
• SSUBSCRIBE channel · SPUBLISH channel msg★
  Sharded pub/sub (7.0+) — scales in a cluster.
• PUBSUB SHARDCHANNELS · SHARDNUMSUB
  Introspect sharded channels (7.0+).
• PUBSUB CHANNELS [pattern] · NUMSUB
  List active channels / subscriber counts.
• // sharded emits 'smessage', not 'message'
  Use SSUBSCRIBE for cluster-local, SUBSCRIBE for global.

• EVAL "return redis.call('GET',KEYS[1])" 1 k★
  Run an inline Lua script atomically.
• SCRIPT LOAD "..." → EVALSHA sha 1 k★
  Cache by SHA, call without re-sending the body.
• EVAL_RO / EVALSHA_RO
  7.0+ read-only variants — safe on replicas.
• SCRIPT EXISTS sha · SCRIPT FLUSH
  Check cache; clear all cached scripts.
• // EVAL scripts are ephemeral — lost on restart
  For durable logic use Functions (next card).

• FUNCTION LOAD "#!lua name=mylib ..."★
  Load a named library; persists & replicates like data.
• FCALL myfunc 1 key arg★
  Call a registered function by name.
• FCALL_RO myfunc 1 key
  Read-only call — runs on replicas.
• FUNCTION LIST · FUNCTION STATS
  Inspect libraries / running functions.
• FUNCTION DUMP · FUNCTION RESTORE
  Serialize / reload all libraries.
• FUNCTION DELETE mylib · FLUSH
  Remove one library / all of them.

• JSON.SET k $ '{"n":"Ada","tags":[]}'★
  Store a JSON document at the root path.
• JSON.GET k $.n★
  Fetch by JSONPath.
• JSON.SET k $.age 36
  Update a sub-path in place.
• JSON.NUMINCRBY k $.age 1
  Atomic numeric increment on a path.
• JSON.ARRAPPEND k $.tags '"db"'★
  Append to an array field.
• JSON.DEL k $.tmp · JSON.TYPE · JSON.OBJKEYS
  Delete a path; inspect type / keys.
• // index JSON with FT.CREATE ... ON JSON
  Query documents via the Query Engine.

• FT.CREATE idx ON JSON PREFIX 1 "doc:" SCHEMA $.name AS name TEXT $.age AS age NUMERIC★
  Define a secondary index over hashes/JSON.
• FT.SEARCH idx "@name:Ada @age:[30 40]"★
  Full-text + tag + numeric query.
• FT.AGGREGATE idx "*" GROUPBY 1 @city REDUCE COUNT 0 AS n★
  Group / reduce / sort like a mini-SQL.
• FT.SEARCH idx "@vec:[VECTOR_RANGE ...]"
  Vector KNN inside a query (stemming, fuzzy, synonyms too).
• FT.HYBRID ...
  8.2 — fuse full-text + vector with RRF ranking.
• FT.INFO idx · FT.DROPINDEX idx
  Inspect / drop an index (keeps the docs).

• VADD k VALUES 4 0.1 0.2 0.3 0.4 elem★
  Add a vector embedding under a member name.
• VSIM k VALUES 4 0.1 0.2 0.3 0.4 COUNT 10★
  Find the nearest members (semantic search).
• VSIM k ELE elem COUNT 5
  Similar items to an existing member (recommendations).
• VDIM k · VCARD k · VREM k elem
  Dimensions; count; remove a vector.
• // inspired by sorted set; beta API may change
  Complements Query-Engine vector fields for RAG.

• TS.CREATE temp RETENTION 86400000 LABELS sensor a★
  Create a series with retention & labels.
• TS.ADD temp * 21.5★
  Append a sample (* = now).
• TS.RANGE temp - + AGGREGATION avg 60000★
  Range query with downsampling buckets.
• TS.MRANGE - + FILTER sensor=a★
  Query many series by label filter.
• TS.CREATERULE src dst AGGREGATION avg 60000
  Auto-downsample into a compaction series.
• TS.INFO temp · TS.GET temp
  Metadata / latest sample.

• BF.ADD k item · BF.EXISTS k item★
  Bloom filter — "seen before?" no false negatives.
• CF.ADD / CF.EXISTS / CF.DEL k item
  Cuckoo filter — like Bloom but supports deletion.
• CMS.INCRBY k item 1 · CMS.QUERY
  Count-min sketch — approximate frequency counts.
• TOPK.ADD k item · TOPK.LIST k★
  Top-K — heavy hitters / trending items.
• TDIGEST.ADD k 12.5 · TDIGEST.QUANTILE k 0.99
  t-digest — percentiles over a stream (p99 latency).
• // tiny fixed memory for billions of items
  Trade exactness for massive space savings.

• SAVE · BGSAVE★
  RDB snapshot — blocking / background fork.
• BGREWRITEAOF★
  Compact the append-only file.
• CONFIG SET appendonly yes★
  Enable AOF; 7.0 uses multi-part AOF (base + incr + manifest).
• LASTSAVE
  Unix time of the last successful save.
• CONFIG SET appendfsync everysec
  Fsync policy: always / everysec / no.
• // RDB = compact snapshots; AOF = op log
  Combine both for the best durability trade-off.

• REPLICAOF host port★
  Make this node a replica (NO ONE to promote).
• INFO replication★
  Role, connected replicas, offsets, lag.
• WAIT numreplicas timeout★
  Block until N replicas ack the writes.
• CONFIG SET repl-diskless-sync yes
  Stream the RDB over the socket, skip disk.
• FAILOVER [TO host port]
  Coordinated, safe failover (6.2+).
• // Sentinel adds automatic failover + discovery
  redis-sentinel monitors & promotes replicas.

• CLUSTER INFO · CLUSTER NODES★
  Cluster health & node topology.
• CLUSTER SHARDS · CLUSTER SLOTS★
  Slot → node mapping (SHARDS 7.0+).
• CLUSTER KEYSLOT key
  Which of the 16384 hash slots a key lands in.
• CLUSTER ADDSLOTSRANGE 0 5000 · DELSLOTSRANGE
  7.0+ — assign slot ranges in one call.
• CLUSTER LINKS
  7.0+ — inspect inter-node link state.
• // use {tag} in keys to co-locate on one slot
  Hash tags keep related keys together for MULTI.

• ACL SETUSER alice on >pw ~cache:* +@read★
  User + password + key pattern + command category.
• ACL SETUSER alice (~session:* +set +get)★
  Selectors (7.0+) — extra permission sets in parens.
• ACL GETUSER alice · ACL LIST★
  Inspect a user / list all rules.
• ACL WHOAMI · ACL CAT
  Current user; list command categories.
• ACL DRYRUN alice GET foo★
  7.0+ — test if a user could run a command.
• AUTH [user] pass · ACL DELUSER alice
  Authenticate; remove a user.
• // 8.0: @search @json @timeseries @bloom cats
  New ACL categories fold module commands into @read/@write.

• CLIENT TRACKING ON★
  Server-assisted client-side caching invalidation.
• CLIENT NO-TOUCH ON
  7.2+ — read keys without bumping LRU/LFU.
• CLIENT NO-EVICT ON
  7.0+ — exempt this connection from eviction.
• CLIENT LIST · CLIENT INFO★
  Inspect connections & their state.
• CLIENT KILL ID n · CLIENT UNPAUSE
  Terminate a client; resume paused traffic.
• CLIENT SETNAME · CLIENT GETNAME
  Label a connection for observability.

• CONFIG GET maxmemory · CONFIG SET maxmemory 2gb★
  Read / change config at runtime.
• CONFIG SET maxmemory-policy allkeys-lru★
  Eviction policy when memory is full.
• INFO [section]★
  Server stats: memory, clients, stats, keyspace.
• DBSIZE · MEMORY USAGE key · MEMORY DOCTOR
  Key count; per-key bytes; memory advice.
• SLOWLOG GET [n|-1]
  Slow commands; -1 returns all (7.0+).
• CONFIG REWRITE · CONFIG RESETSTAT
  Persist config to file; reset counters.

Core

Streaming & probabilistic

Document & geo

AI

• CONFIG SET notify-keyspace-events KEA★
  Enable events (K keyspace, E keyevent, A all).
• PSUBSCRIBE "__keyevent@0__:expired"★
  React to key expirations (cache-invalidation hook).
• PSUBSCRIBE "__keyspace@0__:user:*"
  All events on matching keys.
• // 8.0 adds OVERWRITTEN & TYPE_CHANGED events
  Finer visibility into what changed.
• // events are best-effort, fire-and-forget
  Not durable — pair with streams if you need delivery.

• FLUSHDBwipes db
  Delete every key in the current database.
• FLUSHALLwipes all
  Delete every key in every database.
• KEYS *blocks
  Scans all keys — freezes the server in prod. Use SCAN.
• CONFIG SET appendonly nodurability
  Disables AOF — risk of data loss on crash.
• SHUTDOWN NOSAVEno save
  Stop the server without persisting.
• // rename-command in config to disable these
  Neuter FLUSHALL/KEYS on production instances.