Get the node address of an executed command in cluster mode

[longxice]

Hi all,

I would like to use the node address for metrics. That helps to identify which commands are sent to a node in the cluster.
However, I don't sure the way to get it.

I intend to get the node address of the executed command as follows:
Step 1: Get the key slot by calling cmd.Slot().
Step 2: Use reflection to call clusterClient._pick(...).

However, after executing the command, there may be a hash slot change caused by Redis failover.

Could you point out the correct way?

[rueian]

Hi @longxice,

Unfortunately, getting the exact address is impossible currently. Unless we expend the CommandSlice
struct

rueidis/internal/cmds/builder.go

Lines 16 to 20 in 9a347d7

	type CommandSlice struct {
	s []string
	l int32
	r int32
	}

and inject destination into the it from here

rueidis/mux.go

Line 54 in 9a347d7

dst string

[rueian]

But we also need to consider if there is a notable performance impact due to the changes.

[longxice]

Hi @rueian

Thank you for your response.

I hope this feature will be released soon.

Thank you.

[rueian]

Yes, but we don’t have an ETA for this. This could have great impact in terms of performance. I currently have no idea how big it could be.

Also this may related ro #454.