Essential Redis Monitoring Metrics and Commands for Effective Operations

Monitoring Metrics

Performance

Memory

Basic activity

Persistence

Error

Monitoring Methods

redis-benchmark

redis-stat

redis-faina

redislive

redis-cli

monitor

showlog

Key slowlog commands:

get

(retrieve slow query log),

len

(log entry count),

reset

(clear log).

Relevant configuration:

slowlog-log-slower-than 1000 # threshold in microseconds
slowlog-max-len 100 # max number of log entries

The

info

command can fetch all or specific sections of server information.

server – server environment parameters

clients – client-related information

memory – memory statistics

persistence – persistence information

stats – general statistics

Replication – master‑slave replication details

CPU – CPU usage

cluster – cluster information

Keyspace – key‑value statistics

Example usage:

./redis-cli info | grep ops            # operations per second
./redis-cli info stats | grep ops
./redis-cli info server

Performance Monitoring

redis-cli info | grep ops # operations per second

Memory Monitoring

[root@CombCloud-2020110836 src]# ./redis-cli info | grep used | grep human
used_memory_human:2.99M  # total memory allocated by allocator
used_memory_rss_human:8.04M  # memory as seen by OS (top)
used_memory_peak_human:7.77M # peak memory consumption
used_memory_lua_human:37.00K # Lua engine memory usage

Blocked clients caused by BLPOP/BRPOP/BRPOPLPUSH:

./redis-cli info | grep blocked_clients
blocked_clients:0

Keys evicted due to max‑memory limit:

./redis-cli info | grep evicted_keys
evicted_keys:0

Memory fragmentation ratio:

./redis-cli info | grep mem_fragmentation_ratio
mem_fragmentation_ratio:2.74

Used memory:

./redis-cli info | grep used_memory:
used_memory:3133624

Basic Activity Metrics

Number of connected clients indicates unexpected connections; use

client list

to investigate.

./redis-cli info | grep connected_clients
connected_clients:1

./redis-cli info | grep connected
connected_clients:1   # client connections
connected_slaves:1    # slave connections

Persistence Metrics

./redis-cli info | grep rdb_last_save_time
rdb_last_save_time:1591876204  # timestamp of last RDB save
./redis-cli info | grep rdb_changes_since_last_save
rdb_changes_since_last_save:0   # changes since last save

Error Metrics

High rejected connections indicate low

maxclients

setting.

./redis-cli info | grep connected_clients
connected_clients:1

Keyspace misses (lookup failures):

./redis-cli info | grep keyspace
keyspace_misses:0

Replication backlog size and partial sync errors help assess replication health:

./redis-cli info | grep repl_backlog_size
repl_backlog_size:1048576
./redis-cli info | grep sync_partial_err
sync_partial_err:1

Redis Performance Test Commands

./redis-benchmark -c 100 -n 5000

This runs a benchmark with 100 concurrent connections and 5,000 requests.