Talk:Two-phase commit protocol: Difference between revisions

Revision as of 19:11, 6 September 2006

Revision as of 09:18, 30 October 2006

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As per earlier comments, I wonder if more discussion could be given in the "Disadvantages" paragraph regarding what it actually means to be biased towards aborts rather than towards commits.

[[User:Nbeckman|Nels Beckman]] 19:11, 6 September 2006 (UTC)

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I just modified the section on disadvantages, since it contained some mistakes.

1. The usual 2PC uses a timeout to avoid that the coordinator blocks forever. This is the reason why the protocol is biased towards aborts.

2. I removed the passage "Also it cannot recover from cases where a node has failed in the commit stage (due to internal or network failures) after indicating that it is ready to commit. In this case, resources that committed prior to this failure cannot be rolled back." This will never occur if the protocol is implemented properly: A cohort will only vote for commit if it can guarantee successful completion, even in the case of a failure. So, prior to voting for commit the cohort will log the necessary information for transaction redo.