Vector Logical time

In a vector clock system with 3 processes, if process P1 has vector [2,1,0] and receives a message from process P2 with vector [1,3,1], what will P1's vector be after processing this message?

a: [2,3,1] Explanation

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b: [3,4,1] Explanation

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c: [3,3,1] Explanation

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d: [2,4,1] Explanation

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When a process performs a local event (not involving message passing), what changes in its vector clock?

a: All components are incremented Explanation

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b: Only its own component is incremented Explanation

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c: The vector remains unchanged Explanation

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d: All components are set to the maximum value Explanation

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In the vector clock algorithm, what information does a process include when sending a message?

a: Only its own clock value Explanation

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b: Its complete current vector timestamp Explanation

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c: The difference between current and previous vector Explanation

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d: Only the components that have changed Explanation

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Consider two events with vectors A=[3,2,4] and B=[2,3,4]. What is the causal relationship between these events?

a: A happens before B Explanation

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b: B happens before A Explanation

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c: A and B are concurrent Explanation

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d: A and B are identical Explanation

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In a distributed system running vector clocks, what does it mean when a process cannot proceed with event processing?

a: The system has detected a deadlock cycle Explanation

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b: The process is waiting for a message to arrive before updating its clock Explanation

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c: The vector clock has reached its maximum value Explanation

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d: Another process has failed Explanation

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What is the purpose of the 'tick' or increment value in vector clock implementations?

a: To synchronize with physical time Explanation

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b: To differentiate between processes with different execution speeds Explanation

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c: To prevent integer overflow Explanation

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d: To compress the vector size Explanation

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In the context of distributed consistency, why might a system show inconsistent states even with vector clocks?

a: Vector clocks are inherently unreliable Explanation

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b: Message passing creates temporary states where not all causal dependencies have been resolved Explanation

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c: The vector clock algorithm has bugs Explanation

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d: Physical clock drift affects vector clocks Explanation

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What is the computational complexity of determining the causal relationship between two events using their vector timestamps?

a: O(1) - constant time Explanation

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b: O(log n) - logarithmic in number of processes Explanation

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c: O(n) - linear in number of processes Explanation

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d: O(n²) - quadratic in number of processes Explanation

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In a vector clock system, under what conditions can we guarantee that all events in the system can be assigned a total ordering?

a: When all processes use the same tick increment Explanation

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b: When we use additional tie-breaking rules (like process IDs) for concurrent events Explanation

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c: When the system has no message passing Explanation

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d: When all clocks are synchronized to physical time Explanation

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