Host Network Membership Maintenance During Controller Disconnection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In software-defined data centers, hosts may experience communication disruptions due to outdated or inaccurate overlay network membership information when disconnected from the controller, leading to issues with broadcasting, unknown destination, or multicast data packets.
Innovation Solution
Hosts are configured to maintain network membership by identifying and selecting other hosts within the control logical network, allowing them to send broadcast, unknown destination, or multicast data packets even when disconnected from the controller, using a process that updates and replicates data packets within network segments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a host relies on the controller for overlay network membership information, then the controller can centrally manage network membership, but the host cannot communicate with new network members when disconnected from the controller
Solution Approach 1:
The host performs preliminary actions by caching membership information locally and proactively discovering new members through broadcast packets before disconnection occurs. This ensures that even when disconnected from the controller, the host retains the ability to communicate with network members without waiting for controller updates.
Solution Approach 2:
The host becomes self-sufficient by maintaining its own membership information through local caching and active discovery mechanisms. Instead of passively relying on controller updates, the host independently manages its membership state by monitoring broadcast packets and updating its local database, enabling autonomous operation during controller disconnection.
2Ease of operation
If the host waits for controller connection restoration to update membership information, then the controller can maintain centralized control, but the host cannot send broadcast or multicast packets to new members during disconnection
Solution Approach 1:
The host performs preliminary discovery of new members and updates its membership information proactively during the disconnection period by monitoring broadcast packets. This preliminary action ensures that when the connection is restored, the host already has up-to-date membership information and can immediately communicate with all network members without delay.
Solution Approach 2:
The host maintains continuous operation by persistently sending broadcast packets and monitoring for membership updates even during controller disconnection. This continuous action ensures that the host remains informed of network changes and can maintain communication without interruption once the connection is restored, eliminating communication delays.
3Loss of information
If the host uses broadcast packets to discover members during disconnection, then the host can maintain network awareness, but the controller cannot actively push updates to the disconnected host
Solution Approach 1:
The host independently manages its membership information by actively monitoring broadcast packets and updating its local database without requiring controller intervention. This self-service approach ensures accurate membership information is maintained through passive listening and active discovery, avoiding the complexity of implementing sophisticated pull-based update mechanisms during disconnection.
Data Source
AI summary
Exemplary methods, apparatuses, and systems maintain network membership information for a host when it is disconnected from a controller. When the host detects a loss of connectivity with the network controller, the host identifies and selects one or more hosts that are members of a control logical network. The control logical network includes hosts configured to run data compute nodes that are members of the overlay network, regardless of whether or not each of the hosts is currently running a data compute node that is a member of the overlay network. The host then sends any broadcast, unknown destination, or multicast (BUM) data packet(s) to the selected one or more hosts.