Redis CLI Commands

Connecting

Default port is 6379. Build a URL for your host with the Redis connection string generator.

Example: connect over TLS to database 1 without leaving the password in your shell history.

export REDISCLI_AUTH='s3cret'
redis-cli -u rediss://[email protected]:6380/1 PING   # PONG over TLS
redis-cli -u rediss://[email protected]:6380/1

Keys

Use SCAN to list keys. KEYS walks the whole keyspace in one blocking call. Turn seconds into readable TTLs with the Redis TTL converter.

In 1bench: the Redis GUI shows keys as a namespace tree with types and TTLs, loaded with SCAN, so you can find a key without typing KEYS * against production.

Example: count the session keys, then list the ones that have no TTL.

redis-cli --scan --pattern 'session:*' | wc -l   # how many sessions exist
redis-cli --scan --pattern 'session:*' | while read -r k; do   # which never expire
  [ "$(redis-cli TTL "$k")" = "-1" ] && echo "$k"
done

Strings

Example: a per-minute rate limit for user 1001, built from INCR and EXPIRE ... NX.

redis-cli INCR rate:1001:202610121405              # (integer) 1, reject above 100
redis-cli EXPIRE rate:1001:202610121405 60 NX      # window closes after a minute

Hashes

HMSET still works but is deprecated. HSET takes multiple pairs.

In 1bench: the Redis GUI lets you edit several hash, list, set or sorted set fields and save them together. Each write checks the key has not changed since you loaded it and keeps its TTL.

Example: store a user profile as a hash, bump its login count and read three fields back.

redis-cli HSET user:1001 name "Ada Lovelace" email [email protected] plan pro logins 0
redis-cli HINCRBY user:1001 logins 1
redis-cli HMGET user:1001 name plan logins   # "Ada Lovelace", "pro", "1"

Sorted Sets

Since Redis 6.2, ZRANGE covers what ZREVRANGE and ZRANGEBYSCORE did. The old commands still run.

Example: a weekly leaderboard that adds points for two users and reads back the top three.

redis-cli ZINCRBY leaderboard:2026-w41 120 user:1001
redis-cli ZINCRBY leaderboard:2026-w41 95 user:1002
redis-cli ZRANGE leaderboard:2026-w41 0 2 REV WITHSCORES   # user:1001 120, user:1002 95

Streams

An append-only log with consumer groups. Entry IDs look like 1760270400000-0; * lets Redis pick one.

Example: create a billing consumer group, add an order, read it as worker-1 and acknowledge it.

redis-cli XGROUP CREATE orders billing $ MKSTREAM
redis-cli XADD orders '*' order_id 42 user 1001 total 49.90
redis-cli XREADGROUP GROUP billing worker-1 COUNT 1 STREAMS orders '>'   # returns ID 1760270400000-0
redis-cli XACK orders billing 1760270400000-0

Lists and Sets

Example: a job queue that parks each job on a processing list until the worker removes it.

redis-cli RPUSH jobs '{"id":7,"type":"invoice","order":42}'
redis-cli BLMOVE jobs jobs:processing LEFT RIGHT 5   # held here until the worker finishes
redis-cli LREM jobs:processing 1 '{"id":7,"type":"invoice","order":42}'

Pub/Sub

Messages go only to clients subscribed at that moment. Nothing is stored; use a stream when you need history.

Example: watch expiry events in one terminal while a 5-second session key expires in another.

redis-cli CONFIG SET notify-keyspace-events Ex
redis-cli PSUBSCRIBE '__keyevent@0__:expired'   # terminal 1: watch expiries

redis-cli SET session:abc 1001 EX 5              # terminal 2: fires in 5 seconds

Transactions and Lua

Example: take a lock with SET NX PX, then release it with Lua only if this worker still holds it.

cat > release.lua <<'EOF'   # delete the lock only if this worker holds it
if redis.call('GET', KEYS[1]) == ARGV[1] then
  return redis.call('DEL', KEYS[1])
end
return 0
EOF
redis-cli SET lock:order:42 worker-1 NX PX 30000
redis-cli --eval release.lua lock:order:42 , worker-1   # (integer) 1, lock released

JSON

JSON commands are built into Redis 8. On Redis 7 they need the RedisJSON module (Redis Stack). Shell quoting gets messy with nested JSON; the Redis escape tool helps.

Example: store a preferences document, append a language to its array and read the array back.

redis-cli JSON.SET user:1001:prefs '$' '{"theme":"dark","langs":["en"],"visits":0}'
redis-cli JSON.ARRAPPEND user:1001:prefs '$.langs' '"de"'
redis-cli JSON.GET user:1001:prefs '$.langs'   # [["en","de"]]

Server and Monitoring

Estimate memory before you load data with the Redis memory calculator.

In 1bench: the Redis GUI lays out INFO as a dashboard with memory, ops/sec, hit rate, evictions and per-database key counts.

Example: check memory use, fragmentation and eviction policy, then find the keys using the most memory.

redis-cli INFO memory | grep -E 'used_memory_human|maxmemory_human|mem_fragmentation_ratio'
redis-cli CONFIG GET maxmemory-policy
redis-cli --memkeys

Valkey and Dragonfly

Valkey is a fork of Redis 7.2.4, so every command above works and valkey-cli takes the same flags as redis-cli. Dragonfly speaks the Redis protocol on port 6379 and works with redis-cli; these rows differ.

Example: run Dragonfly in Docker as a password-protected cache and ping it with redis-cli.

docker run -d -p 6379:6379 --ulimit memlock=-1 \
  docker.dragonflydb.io/dragonflydb/dragonfly --requirepass s3cret --cache_mode=true
REDISCLI_AUTH=s3cret redis-cli PING

Gotchas

• KEYS * runs on the single command thread and checks every key before it returns, so on a large database every other client waits. Use SCAN or redis-cli --scan. SCAN can return a key twice and COUNT is a hint, not a page size.
• FLUSHALL wipes every database on the server, not only the one you selected, and there is no undo. Protect production with an ACL rule such as -flushall -flushdb for app users.
• DEL on a hash or list with millions of items blocks while it frees memory. UNLINK returns at once and frees in the background.
• A plain SET on an existing key removes its TTL. Add KEEPTTL, or set the TTL again in the same call with EX.
• In a cluster, multi-key commands such as MGET, MULTI blocks and Lua scripts fail with CROSSSLOT unless every key hashes to the same slot. Put the shared part in braces: {user:1001}:cart and {user:1001}:prefs.
• -a secret and passwords in -u URLs end up in shell history and process lists. Use --askpass or the REDISCLI_AUTH environment variable.