The recent deployment of cloudelastic, the third elasticsearch cluster we write to, has made our mediawiki job response times for writes incredibly erratic. Additionally cloudelastic isn't nearly as powerful ( ~1/10 the size) and can't always keep up with the full update rate. To support this use case we want to partition these jobs such that each cluster can be written to independently.
The overall goal is to allow cloudelastic to fall behind and catch back up at it's own pace, independent from the primary clusters. Any slowdowns with cloudelastic needs to have little, if any, impact on writes to the primary clusters.