System and method for block conflict resolution within consistency interval marker based replication

• Main Authors: Tawri, Deepak, Karr, Ronald S, Colgrove, John A, Krishnamurthy, Raghu, Kekre, Anand A, Baird, Robert, Kiselev, Oleg
• Format: Patent
• Language: English
• Published: 16.12.2008

One goal of consistency interval replication is to achieve a consistent copy of data generated by independent streams of writes from nodes in a clustered/distributed environment. Two writes to the same block from different nodes may arrive at a replication target in a different order from the order in which they were written to primary storage. A consistency interval coordinator may analyze a list of blocks modified during a consistency interval to determine conflict blocks written to by two different nodes during the same consistency interval. Conflict resolution may involve a node reading data for a conflict block from primary storage and forwarding it to the replication target or a node completing a suspended in-progress write for the conflict block. Once the conflicts have been resolved, the replication target may checkpoint the data modified during the interval and nodes may resume writes to the conflict blocks for the new interval.