Chunk and meta server: make "chunks available" protocol resilient to concurrent "stale chunks" RPC generated by the meta server in response to other than chunks available "events", for example chunk replication or recovery failure, by adding the corresponding chunk available RPC sequence number to the related stale chunk RPC(s). Ignore stale chunk RPCs if chunk id matches any of the chunk available RPC in flight, unless the stale chunk RPC's available chunk RPC sequence matches. The existing logic "prefers" that the corresponding stale chunks arrive prior to chunk available RPC completion.