Run certain commands from the advanced cluster connection on multiple hosts

[mp911de]

RedisAdvancedClusterConnection still feels like redis-cli on certain commands. While key-bound commands are routed to the appropriate master, some key-less commands are executed only on the underlying node for the main cluster connection. Some commands can be executed either on masters, slaves, or both to improve the cluster feeling. Some commands imply to select, where to run, either slaves or masters to benefit from eventual consistency and performance. This will be handled in a future task.

Following commands should be executed on multiple hosts:

• CLIENT SETNAME: all nodes
• DBSIZE: master nodes, sum up the size from all master nodes
• FLUSHALL: master nodes
• FLUSHDB: master nodes
• KEYS: master nodes
• RANDOMKEY: run on a random master
• SCAN: master nodes
• SCRIPT FLUSH: all nodes
• SCRIPT KILL: all nodes
• SHUTDOWN: all nodes

[mp911de]

Omitting SCAN for now due the low benefit. Executing SCAN requires some effort in API design to also get rid the redis-cli feeling.