Anycast CDN Route Controller for Load Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current content distribution networks face challenges in efficiently managing load and reducing latency across geographically dispersed servers, particularly in unstable networks with frequent internal routing changes, which can disrupt connections and increase retrieval times for digital content.
Innovation Solution
The implementation of an anycast content delivery network (CDN) system that dynamically redirects content requests to the closest available cache server based on network cost, latency, and load conditions, using a route controller to manage traffic and provide either anycast or unicast IP addresses to optimize content delivery, while avoiding overloaded or unstable servers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If content requests are distributed to geographically dispersed servers, then content delivery efficiency is improved, but connection stability deteriorates in networks with frequent routing changes
Solution Approach 1:
The system implements feedback mechanisms where the anycast address resolution process monitors network conditions and server status, dynamically adjusting routing decisions. When a cache server becomes unavailable or overloaded, the system receives feedback about this state and redirects subsequent requests to alternative servers, thereby maintaining connection stability while preserving content delivery efficiency.
Solution Approach 2:
The patent employs dynamic server selection where the resolving server adaptively chooses which cache server to return based on current network conditions and server availability. This dynamic approach allows the system to respond to changing network topologies and server states, maintaining both high content delivery efficiency and connection stability in unstable networks.
2Loss of time
If multiple cache servers are used to reduce latency, then content retrieval speed is improved, but system complexity increases
Solution Approach 1:
The anycast address serves multiple functions simultaneously: it acts as a single unified endpoint for clients, enables automatic load distribution across multiple cache servers, and provides implicit failover capability. This multi-functionality reduces system complexity by eliminating the need for complex client-side server selection logic while maintaining low latency through distributed cache servers.
Solution Approach 2:
The anycast address acts as an intermediary that simplifies the interaction between clients and multiple cache servers. Clients only need to know the anycast address, while the underlying complexity of server selection, load balancing, and failover is handled automatically by the network routing infrastructure and resolving servers, thereby reducing overall system complexity.
3Productivity
If dynamic server selection is implemented to optimize content delivery, then load distribution is improved, but routing overhead increases
Solution Approach 1:
The system implements self-service routing where each resolving server independently determines the optimal cache server to service requests based on current network conditions and server status. This eliminates the need for centralized routing control and complex routing protocols, reducing routing overhead while maintaining effective load distribution across the cache server network.
Data Source
AI summary
A system includes first and second cache servers a domain name server, and a route controller. The cache servers are each configured to respond to an anycast address. Additionally, the first cache server is configured to respond to a first unicast address, and the second cache server is configured to respond to a second unicast address. The router controller configured to determine wither the status of the first cache server is non-overloaded, overloaded, or offline. The route controller is further configured to instruct the domain name server to provide the second unicast address when the status is overloaded or offline, and modify routing of the anycast address to direct a content request sent to the anycast address to the second cache server when the status is offline. The domain name server is configured to receive a request from a requestor for a cache server address. Additionally, the domain name server is configured to provide an anycast address to the requestor when the status of the first cache server is non-overloaded, and provide the second unicast address to the requestor when the status of the first cache server is offline or overloaded.