feat: support round robin replica selection #2946
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In one of our production clusters, where we use
SlaveForKey
function to selectively runEVALSHA
, we noticed that the replica selection strategy was random and resulted in an uneven traffic pattern. During high throughput this started showing up with noticeable resource utilisation on some of the nodes compared to other. Ideally this wouldn't have made too big an issue but since we are running lua scripts andevalsha
, it was noticeable.I checked to see if there was a way for clients to inject a routing strategy via ClusterOptions but it isn't supported. Ideally, I think that might make more sense, especially since the client already supports
SlaveForKey
,MasterForKey
,ForEachMaster
andForEachSlave
methods. Immediately for our use case I decide to just add a new route strategy but it might make sense to support custom route functions.Please let me know if this makes sense to be merged back here.