Master Redis Monitoring: Key Metrics, Commands, and Performance Testing

Monitoring Metrics

Performance

Memory

Basic activity

Persistence

Error

Monitoring Methods

redis-benchmark

redis-stat

redis-faina

redislive

redis-cli

monitor

showlog

Slow Log Commands

get – retrieve slow‑query log entries

len – get the number of slow‑query log entries

reset – clear the slow‑query log

Slow Log Configuration

<code>slowlog-log-slower-than 1000  # threshold in microseconds
slowlog-max-len 100           # maximum number of log entries</code>

INFO Command Overview

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‑space statistics

Using INFO

<code>./redis-cli info | grep <section>
# Example: ./redis-cli info stats | grep ops</code>

Performance Monitoring

<code>redis-cli info | grep ops   # operations per second</code>

Memory Monitoring

<code>./redis-cli info | grep used_memory_human
used_memory_human:2.99M          # total memory allocated by allocator
used_memory_rss_human:8.04M      # memory seen by OS (top)
used_memory_peak_human:7.77M     # peak memory consumption
used_memory_lua_human:37.00K    # Lua engine memory usage</code>

Basic Activity Metrics

<code>./redis-cli info | grep connected_clients
connected_clients:1            # number of client connections
connected_slaves:1              # number of slave connections</code>

Persistence Metrics

<code>./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</code>

Error Metrics

<code># Connections rejected due to maxclients limit
# (increase maxclients if the number is high)
# Keyspace misses (lookup failures)
keyspace_misses:0
# Replication backlog size
repl_backlog_size:1048576
# Partial sync errors
sync_partial_err:1</code>

Redis Performance Test

<code>./redis-benchmark -c 100 -n 5000   # 100 clients, 5000 requests</code>

Source: https://blog.51cto.com/yht1990/2503819