Consider six transactions T1, T2, T3, T4, and T5 with:
T1 initiated at site S1 and spawning an agent at site S2,
T2 initiated at site S3 and spawning an agent at site S1,
T3 initiated at site S1 and spawning an agent at site S3,
T4 initiated at site S2 and spawning an agent at site S3,
T5 initiated at site S3.
The locking information for these transactions is shown in following table.

(a) Produce the local wait-for-graphs (WFGs) for each of the sites. What can you conclude from the local WFGs?
(b) Using the above transactions, demonstrate how Obermarck€™s method for distributed deadlock detection works. What can you conclude from the global WFG?

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Transaction Data items locked by transaction Data items transaction is waiting for Site involved in operations ㄒ