Files
Matthew Oliver
2641814010
Add sharder daemon, manage_shard_ranges tool and probe tests
The sharder daemon visits container dbs and when necessary executes the sharding workflow on the db. The workflow is, in overview: - perform an audit of the container for sharding purposes. - move any misplaced objects that do not belong in the container to their correct shard. - move shard ranges from FOUND state to CREATED state by creating shard containers. - move shard ranges from CREATED to CLEAVED state by cleaving objects to shard dbs and replicating those dbs. By default this is done in batches of 2 shard ranges per visit. Additionally, when the auto_shard option is True (NOT yet recommeneded in production), the sharder will identify shard ranges for containers that have exceeded the threshold for sharding, and will also manage the sharding and shrinking of shard containers. The manage_shard_ranges tool provides a means to manually identify shard ranges and merge them to a container in order to trigger sharding. This is currently the recommended way to shard a container. Co-Authored-By: Alistair Coles <alistairncoles@gmail.com> Co-Authored-By: Tim Burke <tim.burke@gmail.com> Co-Authored-By: Clay Gerrard <clay.gerrard@gmail.com> Change-Id: I7f192209d4d5580f5a0aa6838f9f04e436cf6b1f