POSIX close(2) is broken

Re:POSIX close(2) is broken by eis on Saturday December 17, 2011 @06:20AM (#3364030)

Is eventually known consistency even possible if at any point while the notification of consistency is being transferred to you, the system can enter a non/eventual-consistent state again?

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Re:POSIX close(2) is broken by cperciva on Saturday December 17, 2011 @06:28AM (#3364043)

By "eventually known consistency" I don't mean "at some point I will know that the system is consistent"; rather, I mean "at some point I will know that the system is consistent with respect to operation X" (or alternatively "... with respect to all operations performed before time T").

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Re:POSIX close(2) is broken by nknight on Saturday December 17, 2011 @06:34AM (#3364052)

There's actually two distinct things you might want to know:

1) The current state of the system.

2) Whether the current state of the system is equal to or later than one reflecting your change.

#1 is technically unknowable without a locking mechanism, but #2 is theoretically possible. Assuming reliable time synchronization, your worst-case scenario would be a timestamp on every record, and checking the timestamp on each node (you can do this with Cassandra, for example).

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