GFS Consistency Model
Explore the Google File System (GFS) consistency model, focusing on how it manages file mutations and concurrent writes. Learn the implications for data consistency, application design strategies using appends, and contrasts with Hadoop Distributed File System (HDFS). Understand how these models impact real-world distributed file system operation and data processing.
GFS provides a custom consistency model for write operations.
The state of a file region after a mutation depends on the type of mutation, whether it succeeds or fails and whether there are concurrent mutations.
Note: A file region is consistent if all clients will always see the same data, regardless of the replica they read from.
A region within a file
A region is defined after a file data mutation if it is consistent and clients will see what the mutation writes in its entirety.
A region can be:
- Defined and consistent: When a mutation succeeds without interference from concurrent writes, the affected region is defined. All clients will always see what the mutation