[redisreceiver] Add additional Redis metrics to redisreceiver for better observability

[shmsr]

Component(s)

receiver/redis

Is your feature request related to a problem? Please describe.

Redis provides extensive metrics through its INFO command that are valuable for monitoring Redis performance, memory usage, persistence operations, and replication health. Currently, the Redis receiver only collects a subset of these metrics, leaving gaps in observability. This enhancement request proposes adding several important metrics that are available in Redis INFO command output but not currently collected by the receiver.

Describe the solution you'd like

Memory Management Metrics

• redis.memory.overhead - Memory overhead used by Redis internal data structures
• redis.memory.startup - Initial memory consumed by Redis at startup
• redis.total_system_memory - Total system memory available

Persistence Metrics

• redis.rdb.last_save_time - Timestamp of last successful RDB save operation
• redis.rdb.saves - Total number of RDB saves performed
• redis.aof.rewrites - Number of AOF rewrite operations

and many more.

Example Redis INFO fields

used_memory_overhead:869640
used_memory_startup:799968
total_system_memory:51539607552
rdb_last_save_time:1750279003
rdb_saves:0
aof_rewrites:0
repl_backlog_size:1048576
repl_backlog_active:0
sync_full:0
sync_partial_ok:0
hz:10
total_forks:0

Describe alternatives you've considered

No response

Additional context

This enhancement aligns with the goal of providing comprehensive Redis monitoring capabilities. Some of the proposed metrics are commonly used.

[github-actions]

Pinging code owners:

• receiver/redis: @dmitryax @hughesjj

See Adding Labels via Comments if you do not have permissions to add labels yourself.

[shmsr]

I'd like to take this up.

[axw]

Sounds sensible to me. I'll optimistically assign you, let's see what the code owners have to say.