Diagnosing distributed virtual network malfunction

A non-transitory, computer-readable storage medium encoded with instructions executable by a processor to diagnose one or more malfunctions in a virtual network having a network functionality implemented by hypervisors in a distributed manner set by a virtual network controller, each hypervisor performing part of the network functionality, the instructions comprising:

• receiving user input of observed facts about the virtual network, the observed facts including identifiers of virtual components in the virtual network;
• adding the observed facts to a knowledge base;
• in response to the identifiers of the virtual components, querying agents on the hypervisors and the virtual network controller for collected facts related to the virtual components;
• receiving and adding the collected facts to the knowledge base;
• and
• applying logic rules to the knowledge base to produce one or more diagnoses of the virtual network.

A system, comprising:

• physical host computers;
• hypervisors on the physical host computers;
• a virtual network controller setting a distributed manner by which the hypervisors implement a network functionality, each hypervisor performing part of the network functionality;
• agents on the hypervisors and the virtual network controller;
• a diagnostic tool comprising a logic engine configured to:
• receive user input of observed facts about the virtual network, the observed facts including identifiers of virtual components in the virtual networking system;
• add the observed facts to a knowledge base;
• in response to the identifiers of the virtual components, query the agents for collected facts related to the virtual components;
• receiving and adding the collected facts to the knowledge base;
• and
• applying logic rules to the knowledge base to produce one or more diagnoses of the virtual network.