Redis

Setup

Prometheus metrics for redis can be enabled using redis exporter. Once the exporter is setup check the following metrics to verify the setup:

• redis_up

• redis_uptime_in_seconds

Metrics

Request, Errors, and Latency

Metric	KPI
Request Counter redis_commands_total redis_connections_received_total	Request Rate rate(redis_commands_total[5m]) rate(redis_connections_received_total[5m])
Error Counter redis_rejected_connections_total	Error Ratio rate(request_connections[5m])/ rate(redis_connections_received_total[5m])
Latency Counter redis_commands_duration_seconds_total	Latency Average rate(redis_commands_duration_seconds_total[5m])/ rate(redis_commands_total[5m])

Resource

Metric	KPI
CPU Usage redis_cpu_user_seconds_total redis_cpu_sys_seconds_total	rate(redis_cpu_user_seconds_total[5m]) + rate(redis_cpu_sys_seconds_total[5m])
Memory Usage redis_memory_used_rss_bytes	redis_memory_used_rss_bytes / redis_memory_max_bytes
Network Bytes Received redis_net_input_bytes_total Network Bytes Transmitted redis_net_output_bytes_total	Data transfer rate rate(redis_net_input_bytes_total[5m) rate(redis_net_output_bytes_total[5m)
Current Redis Connected clients redis_connected_clients	redis_connected_clients / redis_config_maxclients

Alerts

KPI	Alert
Request Rate	RequestRateAnomaly
Error Ratio	ErrorRatioBreach and ErrorBuildup based on an availability SLO of 99.9
Latency Average	LatencyAverageBreach and LatencyAverageAnomaly
CPU Usage	Saturation with severity level of warning and critical when cpu utilization exceeds 70% and 90% respectively
Memory Usage	Saturation with severity level of warning and critical when memory utilization exceeds 65% and 75% respectively
Network Bytes	ResourceRateAnomaly
Client Connections	Saturation with severity level of warning and critical when it exceeds 80% and 90% respectively ResourceMayExhaust if connections are about to exceed the limit of 256 connections within the next 4 hours

Failure Alerts

RedisDown

Redis instance is down

1redis_up != 1

RedisUptimeReset

Redis instance restarted

1delta(redis_uptime_in_seconds[5m]) < 0

RedisMasterLinkDown

Redis master link down

1( 2 avg_over_time(redis_master_link_up[10m]) 3 and on (instance) 4 redis_instance_info{role="slave"} 5) == 0

RedisReplicationBroken

Redis instance lost a replica

1delta(redis_connected_slaves[1m]) < 0

RedisClusterFlapping

Changes have been detected in Redis replica connection

1changes(redis_connected_slaves[5m]) > 2

RedisRejectedConnections

Some connections to Redis have been rejected

1rate(redis_rejected_connections_total[1m]) * 60 > 0

RedisMissingMaster

Redis Master Missing

1count by (job, service, redis_mode, namespace,) 2 (redis_instance_info{role="master"}) == 0

RedisTooManyMasters

Standalone and HA setup should only have one master

1count by (job, service, namespace) 2 (redis_instance_info{role="master", redis_mode="standalone"}) > 1

RedisTooFewMastersInCluster

Redis cluster mode should have every instance in the role of "master"

1avg by (job, service, namespace) (redis_cluster_size) 2- 3count by (job, service, namespace) 4 (redis_instance_info{role="master", redis_mode="cluster"}) 5> 0

KPI Dashboard

Redis KPI Dashboard shows all the above mentioned KPIs