NewGCWorker creates a GCWorker instance.

NewMockGCWorker creates a MockGCWorker instance ONLY for test.

RunDistributedGCJob notifies TiKVs to do GC.

RunGCJob sends GC command to KV.

RunResolveLocks resolves all locks before the safePoint.

ConcurrencyDivisor reduces the input concurrency to avoid overwhelming the system.

RequestsPerThread is the number of requests handled by a single thread.

GCWorker periodically triggers GC process on tikv server.

MockGCWorker is for test.