Redis Configuration Guide: redis.conf Settings, Slowlog, Advanced Options, Replication, and Persistence

This guide explains the most important redis.conf configuration options for running Redis in production.

Basic server settings : daemonize no (run in foreground; set to yes for background), pidfile /var/run/redis.pid (PID file location), port 6379 (listening port), timeout 0 (client idle timeout, 0 disables), loglevel notice (log severity, options: debug, verbose, notice, warning), and logfile stdout (log output, can be redirected to /dev/null).

Connection limits are controlled by maxclients 128, and memory usage by maxmemory <bytes> with policies such as volatile-lru, allkeys-lru, volatile-random, allkeys-random, volatile-ttl, and noeviction. When memory is exhausted, Redis evicts keys according to the selected policy or returns write errors.

Slowlog can be tuned with slowlog-log-slower-than 10000 (record commands slower than 10 ms) and slowlog-max-len (length of the log, unlimited but consumes memory). Use SLOWLOG RESET to free memory.

Advanced data‑structure settings include hash-max-zipmap-entries 512 and hash-max-zipmap-value 64 (compact hash encoding thresholds), activerehashing yes (periodic rehashing of hash tables), list-max-ziplist-entries 512 / list-max-ziplist-value 64 (list compact storage), set-max-intset-entries 512 (set compact integer set), and zset-max-ziplist-entries 128 / zset-max-ziplist-value 64 (zset compact storage).

Replication is configured with slaveof <masterip> <masterport>, masterauth <password> (password for authenticating to the master), and slave-serve-stale-data yes (whether a slave continues serving read‑only data when disconnected from the master).

Persistence options include the save directive (e.g., save 900 1 to snapshot after 1 change within 900 seconds), appendonly yes|no (AOF logging), and appendfsync no|always|everysec (fsync strategy for AOF).