[fsaintjacques]

Can you horizontaly scale the redis backend or it supports only one instance?

Why restrain to sequential reducers when you can parallelize with partitions and sorting?

[heynemann]

We do horizontally scale redis as a farm. I'll try to get more details on how we do it as I'm not the one responsible.

We thought of parallel reducers and it does make a lot of sense. The reason they are sequential is to get a first release out so we can juggle ideas with people. If you care to contribute we'd love it. Even if you just create an issue.