Three-phase commit protocol: Difference between revisions

Revision as of 21:59, 28 March 2020

Revision as of 18:43, 22 April 2020

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==Solution==

The pre-commit phase introduced above helps us to recover from the case when a participant failure or both coordinator and participant node failure during commit phase. When the recovery coordinator takes over after coordinator failure during commit phase of [[two-phase commit]], the new pre-commit comes handy as follows: On querying participants, if it learns that some nodes are in commit phase then it assumes that previous coordinator before crashing has made the decision to commit. Hence it can shepherd the protocol to commit. Similarly, if a participant says that it doesn’t receive PrepareToCommit message, then the new coordinator can assume that the previous coordinator failed even before it startedcompleted the PrepareToCommit phase. Hence it can safely assume no other participant would have committed the changes and hence safely abort the transaction.

==Extensions==