Handling of Network Partitions by 2PC / Two Phase Commit Protocol handling Network Partitions / How does 2PC handle Network Partition failure?
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| Figure - Network Partition - Single network broken into two |
Handling Network Partitions
It refers to the failure of a network
device that leads to the break of one network into two. For more information,
visit Network Partition definitions in Wikipedia and Symantec sites.
During the execution of a
transaction T, if any Network Partition happens, then there are two
possibilities of execution of transaction T.
Possibility 1
The coordinator site and all the other
participating sites may belong to one of the partitions. That is, no sites are
disconnected from the other physically. For this case, we do not need to worry.
The reason is, all the components executing transaction T are available in one
partition. Hence, 2PC does not have anything to do with this failure.
Possibility 2
The coordinator site and all the
other participating sites may belong to several partitions. In this case, the Network
Partition affects the execution.
Now, the sites that are in a
partition which is disconnected from coordinator execute 2PC for handling coordinator failure.
The sites that are in a partition
along with the coordinator execute 2PC for
handling site failure.