Consistency interval marker assisted in-band commands in distributed systems

interval replication coordinator n1°1d; target E — E writes with current 320 interval ID 325 4 write acks 300 consistency interval end msg 305 consistency interval ack 4 310A consistency interval ID msg > consistency interval 330 marker >

interval transition msg 315 indicating that all interval markers received

FIG. 3

nodes insert consistency interval marker into write stream to replication target £2

nodes send writes to replication target including new interval ID E

FIG. 4

block 1 block 2 block 2 block 3 dirty block list dirty block list E m node one node two m M network M block 2 block 1 block 2 _ _ block 2 block 3 preliminary block _°°nfl'ct node one node two “st write log write log E 550 5512 replication target E 1 2 2 3 node one node two dirty block list dirty block list @ fi interval coordinator M2

FIG. 5

block 1 block 2 block 2 block 3 block 4 block 6 block 5 block 7 dirty block list dirty block list m fi mock 3 DIOGK 8 in-progress in'Pr°9r_eSS b|0ck "St b|OCk IISI 600 w node one node two 1 1 0 network 1 1 2 _ m _ block 2 block 1 block 2 block 3 block 2 block 3 final block block 4 block 6 conflict list E block 5 block 7 node one node two write log write log 1 2 2 3 E E 4 5 6 7 replication target E node one node two dirty block list dirty block list @ m interval coordinator E FIG. 6

interval replication coordinator n1°1d; target E — E writes with current 700 interval ID 705 write acks 710 periodic list of 4 ‘ modified blocks 715 consistency interval end msg > 720 list of modified blocks 725 preliminary list of block conflicts ’ writes for non conflict 730 blocks 740 final list of modified blocks 745 final list of block conflicts F conflict resolving 750 writes D consistency interval 760 marker > interval transition msg 765 indicating that all interval ‘ markers received

FIG. 7