MOVE errors when autoPipeline=true and all commands are custom

[jjsimps]

A lot of the calls that I perform to redis are to the JSON redis module, and so I need to use the custom redis.call() function. e.g. client.call('JSON.SET', 'some_key', '$', ...).

However, I noticed that I got the following error rather sporadically:

ReplyError: MOVED 6734 10.16.0.3:31002
    at new Promise (<anonymous>)
    at executeWithAutoPipelining(...)
    ...

I ended up figuring out why this happens:

It seems like when autoPipeline=true and ALL commands sent in the pipeline are custom commands (i.e. only commands sent via client.call(...), the commands are sent to a random node instead.

This is because when the pipelineSlot is calculated based on the keys, it has no keys to reference, as everything is considered as args. This results in a random pipeline slot being chosen. Which is often wrong, so it causes the pipeline to fail.

If there is a single native command though (for example redis.set()), then it is able to determine which node to send it to correctly, and everything works fine. Also, if i set autoPipeline=false, then I get zero move errors. These two observations were made as I was debugging the library code.

It seems like it would need a better way to determine which node to send it to. Either allowing to specify the number of keys with client.call() or a some sort of heuristic that inspects the first arg and assumes that is the key (like it is done elsewhere in the code).

[ezioda004]

I had faced this similar issue, and ended up putting all the JSON commands in autoPipeliningIgnoredCommands options. Ref.