normal replication RS0 Region-A HLog-0 RS1 HLog-1 Peer Cluster RS0 HLog-0 RS1 HLog-1 Peer Cluster Region-A Region-A moved from RS0 to RS1 For region A, Both RS0’s HLog & RS1’s HLog will be replicated replicated to peer cluster in parallel. For region A, Only RS0’s HLog will be replicated to peer cluster. Normal replication - problem #1 Put K0, V0, t1 Put K0, V0, t2 t1 t2 Put K0, V0, t5 t4 of the serial peer. ❏ Barrier: Will store the region’s openNum as its barrier for each region when RS open it. ❏ Last Pushed Sequence ID VS WAL Position: ❏ Last Pushed Sequence ID is a sequence id for

Result-5 Cell-6 Cell-8 Cell-2 Result-2 Cell-3 RegionServer Row Data RPC Response Recieved from RS Results get from scanner.next() Cell-9 Size of cell-1 > 1MB scan.setCaching(2).setAllowPartialResults(true) Result-5 Cell-6 Cell-8 Cell-2 Result-2 Cell-3 RegionServer Row Data RPC Response Recieved from RS Results get from scanner.next() Cell-1 Cell-2 Result-1 Cell-3 Cell-4 Result-2 Cell-5 Result-3 Cell-7 Result-5 Cell-6 Cell-8 Cell-2 Result-2 Cell-3 Cell-9 RegionServer Row Data RPC Response Recieved from RS Results get from scanner.next() Cell-1 Result-1 Cell-4 Result-3 Cell-5 Result-4 Cell-7 Result-5