Chain manager repair for strong consistency remains unfinished #60

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opened 2016-03-29 10:51:50 +00:00 by slfritchie · 0 comments

slfritchie commented

2016-03-29 10:51:50 +00:00

(Migrated from github.com)

Current chain manager repair is eventual consistency mode only. Strong consistency remains future work.

One component that's missing is a FLU operation to undo partial writes: e.g. chain is [A,B], a partial write to A at {File,Offset} is not successfully replicated to B. Then the chain transitions to [B] and then to [B] ++ repairing=[A]. The bytes at {File,Offset} are unwritten on B and therefore must be un-written on A by repair.

Current chain manager repair is eventual consistency mode only. Strong consistency remains future work. One component that's missing is a FLU operation to undo partial writes: e.g. chain is [A,B], a partial write to A at {File,Offset} is not successfully replicated to B. Then the chain transitions to [B] and then to [B] ++ repairing=[A]. The bytes at {File,Offset} are unwritten on B and therefore must be un-written on A by repair.