Many duplicats

[Werner Grift]

As soon as I balance over many CMB instances I get a 20% duplicate message processed count.

Is this to be expected?

[boriwo]

No, you should see practically no duplicates at all. In CMB, Redis is the component that, among other things, eliminates duplicate message delivery. So if you do see many duplicates my guess is that your Redis is either not working, or not configured correctly. For example, say you have 3 Redis shards and 3 CMB nodes. Then the cmb.properties of each of the CMB nodes must list all three Redis shards. Basically each CMB node must be aware of the full list of Redis shards, otherwise you will see duplicates (as would be expected during a Redis outage as well).