摘要:
The backup-in-the-middle primary-backup configuration is created by placing a backup-in-the-middle forwarder in the routing path between the primary and the environment. The backup-in-the-middle forwarder intercepts output messages along with required state information sent by the primary to the environment. The backup-in-the-middle forwarder backs up the primary by updating its state information and forwards the output packets to the environment.
摘要:
The backup-in-the-middle primary-backup configuration is created by placing a backup-in-the-middle forwarder in the routing path between the primary and the environment. The backup-in-the-middle forwarder intercepts output messages along with required state information sent by the primary to the environment. The backup-in-the-middle forwarder backs up the primary by updating its state information and forwards the output packets to the environment.
摘要:
A primary-backup replication capability is disclosed. A primary process and a backup process participate in a synchronization process configured to synchronize state information of the primary and backup processes. The synchronization process operates in periods of time referred to as epochs. During the current epoch, the primary process computes state update information representing changes to the state information of the primary process since a previous epoch, and also buffers output messages generated during the current epoch in an associated output buffer dedicated for use in the current epoch. The primary process initiates a new epoch independent of receiving, from the backup process, a state update acknowledgement for the previous epoch. The output messages buffered for the current epoch are released from the associated output buffer after the primary process receives a state update acknowledgment for the current epoch and all output buffers of all previous epochs are empty.
摘要:
A primary-backup replication capability is disclosed. A primary process and a backup process participate in a synchronization process configured to synchronize state information of the primary and backup processes. The synchronization process operates in periods of time referred to as epochs. During the current epoch, the primary process computes state update information representing changes to the state information of the primary process since a previous epoch, and also buffers output messages generated during the current epoch in an associated output buffer dedicated for use in the current epoch. The primary process initiates a new epoch independent of receiving, from the backup process, a state update acknowledgement for the previous epoch. The output messages buffered for the current epoch are released from the associated output buffer after the primary process receives a state update acknowledgment for the current epoch and all output buffers of all previous epochs are empty.
摘要:
The method includes determining a timestamp corresponding to a received data packet associated with the virtual machine and releasing the data packet from a buffer based on the timestamp and a time another data packet is released from the buffer.
摘要:
The method includes determining a timestamp corresponding to a received data packet associated with the virtual machine and releasing the data packet from a buffer based on the timestamp and a time another data packet is released from the buffer.
摘要:
Methods and apparatus are provided for incremental analysis of one or more properties of a program. According to one aspect of the invention, at least one property of a software program is evaluated, given one or more changes to the software program. Nodes in a derivation graph are identified corresponding to changed edges in a control flow graph representation of the software program, wherein the derivation graph describes an earlier evaluation of the software program. In addition, at least one of the identified nodes in the derivation graph is updated and the derivation graph is traversed outward from a location of a change. The revised derivation graph can optionally be further processed to remove false errors.
摘要:
The present disclosure generally discloses improvements in computer performance for supporting a routing decision validation capability configured to support validation of routing decisions in a communication system. The routing decision validation capability may be configured to validate routing decisions in a communication system including a communication network and a network operating system that is configured to provide control functions for the communication network. The routing decision validation capability may be configured to validate routing decisions for the communication network before the routing decisions are satisfied within the communication network. The routing decision validation capability may be configured to validate routing decisions for the communication network by receiving a routing intent, determining a routing decision for the routing intent, generating a witness for the routing decision, evaluating the witness for the routing decision, and determining whether the routing decision is valid for the routing intent based on the evaluation of the witness for the routing decision.
摘要:
A method and apparatus are provided a method and apparatus for reducing a program that preserves branching time properties, including existential and universal aspects. An alternating transition system (ATS) is abstracted, formed by a product of a program, M, with an alternating tree automaton, A, for a property, f. The disclosed program abstraction method generates the abstract program and an altered version of the branching time property, f. An automated program check, such as a model check, is performed on the abstract program for the altered branching time property. The invention provides semantic completeness: i.e., whenever a program satisfies a property, this can be shown using a finite-state abstract ATS produced by the method. Choice predicates can be employed to help resolve nondeterminism at OR states, and rank functions can be employed to help preserve progress properties.