🕐Logic clock

What is logic clock？

A logical clock is a mechanism for capturing chronological and causal relationships in a distributed system. Often, distributed systems may have no physically synchronous global clock. In many applications (such as distributed GNU make), if two processes never interact, the lack of synchronization is unobservable and in these applications it is enough for the processes to agree on the event ordering (i.e., logical clock) rather than the wall-clock time.[1] The first logical clock implementation, the Lamport timestamps, was proposed by Leslie Lamport in 1978 (Turing Award in 2013).

Local vs global time

In logical clock systems each process has two data structures: logical local time and logical global time. Logical local time is used by the process to mark its own events, and logical global time is the local information about global time. A special protocol is used to update logical local time after each local event, and logical global time when processes exchange data

Algorithms

Some noteworthy logical clock algorithms are:

• Lamport timestamps, which are monotonically increasing software counters.

• Vector clocks, that allow for partial ordering of events in a distributed system.

• Version vectors, order replicas, according to updates, in an optimistic replicated system.

• Matrix clocks, an extension of vector clocks that also contains information about other processes' views of the system.

The role of Logic clock in AOS

The Logic Clock plays a crucial role in the AOS network, enabling secure and efficient verification of AI models and inferences. It serves as a decentralized clock that provides a logical ordering of events and transactions within the network. This logical ordering is essential for maintaining consistency and preventing conflicts or double-spending issues when multiple entities attempt to verify or sample AI models concurrently.

The Logic Clock ensures that each verification or sampling request is processed in a deterministic and reproducible manner, regardless of the order in which it was received by different nodes in the network. This mechanism guarantees that all nodes reach consensus on the state of the AI models and their associated inferences, even in the presence of network latencies or node failures.

Furthermore, the Logic Clock facilitates the creation of checkpoints or snapshots of the AI model states at specific logical times. These checkpoints can be used for efficient rollbacks or replays of the verification process, enabling enhanced auditing and accountability within the AOS network. Overall, the Logic Clock is a fundamental component that underpins the security, consistency, and verifiability of AI inferences in the AOS network, bolstering trust in the AI systems deployed on the Hetu protocol and the Eigenlayer.