Abstract: Methods for determining and utilizing server performance metrics in a network are provided. For example, such methods can involve determining the service availability and metric measurements of types of services provided by a content delivery machine. User weightings can be used to indicate whether more traffic should be sent to one content server address compared to another. DNS servers use the test result updates and/or user weightings to determine the best server to return in response to a request to resolve a given DNS name. Computer systems and apparatus for carrying out such methods are also provided.

Abstract: A system and method providing a testing, monitoring and debugging framework that supports testing web clients with complex and advanced feature sets. The system and method allows multiple web clients to be simultaneously tested on the same physical machine without conflict and records a full range of performance and debugging information by providing detailed measurements at a combination of application and networking layers.

Abstract: Techniques are provided for using the mobility support features of IPv6 to allow client and server nodes to communicate without the continuing intervention of a load-balancing node that selected the server node. A load-balancing node intercepts a TCP SYN packet addressed to a virtual IP address. The load-balancing node selects a server node from among multiple server nodes, and sends the packet toward the server node. The server node sends an IPv6 packet toward the client node. The packet contains a Binding Update option that specifies the virtual IP address as a Home Address. This information causes the client node to replace destination addresses in outgoing IP packets so that packets that the client node would have sent toward the virtual IP address are sent toward the selected server node's IP address instead. Consequently, the IP packets are routed toward the selected server node instead of the load-balancing node.

Abstract: A distributed DNS network includes a central origin server that actually controls the zone, and edge DNS cache servers configured to cache the DNS content of the origin server. The edge DNS cache servers are published as the authoritative servers for customer domains instead of the origin server. When a request for a DNS record results in a cache miss, the edge DNS cache servers get the information from the origin server and cache it for use in response to future requests. Multiple edge DNS cache servers can be deployed at multiple locations. Since an unlimited number of edge DNS cache servers can be deployed, the system is highly scalable. The disclosed techniques protect against DoS attacks, as DNS requests are not made to the origin server directly.

Abstract: A method and mechanism for a distributed on-demand computing system. The system automatically provisions distributed computing servers with customer application programs. The parameters of each customer application program are taken into account when a server is selected for hosting the program. The system monitors the status and performance of each distributed computing server. The system provisions additional servers when traffic levels exceed a predetermined level for a customer's application program and, as traffic demand decreases to a predetermined level, servers can be un-provisioned and returned back to a server pool for later provisioning. The system tries to fill up one server at a time with customer application programs before dispatching new requests to another server. The customer is charged a fee based on the usage of the distributed computing servers.

Abstract: A distributed DNS network includes a central origin server that actually controls the zone, and edge DNS cache servers configured to cache the DNS content of the origin server. The edge DNS cache servers are published as the authoritative servers for customer domains instead of the origin server. When a request for a DNS record results in a cache miss, the edge DNS cache servers get the information from the origin server and cache it for use in response to future requests. Multiple edge DNS cache servers can be deployed at multiple locations. Since an unlimited number of edge DNS cache servers can be deployed, the system is highly scalable. The disclosed techniques protect against DoS attacks, as DNS requests are not made to the origin server directly.

Abstract: A dynamic image delivery system receives a client request for an image at an image caching server. The image caching server measures the client's network access speed and looks for an appropriate pre-rendered copy of the requested image that is rendered for the client's network access speed in local storage. If the appropriate rendered copy is found, then the image caching server sends the rendered image to the client. If it is not found, then the image caching server dynamically renders a copy of the image and sends it to the client.

Abstract: Techniques are provided that allow client and server nodes to communicate without the continuing intervention of a load-balancing node that selected the server node. A load-balancing node intercepts a TCP SYN packet addressed to a virtual IP address. The load-balancing node selects a server node from among multiple server nodes, and sends the packet toward the server node. The server node sends an IPv6 packet toward the client node. The packet contains a Binding Update option that specifies the virtual IP address as a Home Address. This information causes the client node to replace destination addresses in outgoing IP packets so that packets that the client node would have sent toward the virtual IP address are sent toward the selected server node's IP address instead. Consequently, the IP packets are routed toward the selected server node instead of the load-balancing node.

Abstract: A dynamic image delivery system receives a client request for an image at an image caching server. The image caching server measures the client's network access speed and looks for an appropriate pre-rendered copy of the requested image that is rendered for the client's network access speed in local storage. If the appropriate rendered copy is found, then the image caching server sends the rendered image to the client. If it is not found, then the image caching server dynamically renders a copy of the image and sends it to the client.

Abstract: A network of point of presence servers allows a customer to organize their web site by functions where functions are mapped into domain names. The functions have requirements that define what is needed by a server to satisfy the function. The domain names are mapped into resources or servers that can be addressed by the domain name and that satisfy requests for the function that domain name has been defined to support. This method of organization allows individual elements of a web page to be retrieved from different resources and gives the name server the control to direct users to an available and optimal server for a given resource.

Abstract: A method and apparatus for establishing session persistence between a client and an origin server are provided. The session persistence can be managed by an intermediate cache server. The persistence is established by inserting an identifier and origin server address in a cookie or URL. Alternatively, the persistence is established by a table mapping a source IP address or a session ID to a specific origin server. Subsequent requests from the same client are mapped to the same origin server using these methods of establishing persistence.

Abstract: A method and apparatus for serving content requests using global and local load balancing techniques is provided. Web site content is cached using two or more point of presences (POPs), wherein each POP has at least one DNS server. Each DNS server is associated with the same anycast IP address. A domain name resolution request is transmitted to the POP in closest network proximity for resolution based on the anycast IP address. Once the domain name resolution request is received at a particular POP, local load balancing techniques are performed to dynamically select the appropriate Web server at the POP for use in resolving the domain name resolution request. Approaches are described for handling bursts of traffic at a particular POP, security, and recovering from the failure of various components of the system.

Abstract: A method and apparatus for the automatic migration of data via a distributed computer network allows a customer to select content files that are to be transferred to a group of edge servers. Origin sites store all of a customer's available content files. An edge server maintains a dynamic number of popular files in its memory for the customer. The files are ranked from most popular to least popular and when a file has been requested from an edge server a sufficient number of times to become more popular than the lowest popular stored file, the file is obtained from an origin site. The edge servers are grouped into two service levels: regional and global. The customer is charged a higher fee to store its popular files on the global edge servers compared to a regional set of edge servers because of greater coverage.

Abstract: A content delivery and global traffic management network system provides a plurality of caching servers connected to a network. The caching servers host customer content that can be cached and stored, and respond to requests for Web content from clients. If the requested content does not exist in memory or on disk, it generates a request to an origin site to obtain the content. A DNS Server load balances network requests among customer Web servers and directs client requests for hosted customer content to the appropriate caching server. The customer pays a service that provides the content delivery and global traffic management network system a fee for usage of the content delivery and global traffic management network system.

Abstract: A method for operating a network of point of presence servers sharing a hostname includes receiving a request from a user for a web page at a first web address, determining traffic loads of a plurality of customer web servers, determining a customer web server from the plurality of customer web servers, the customer web server having a traffic load lower than traffic loads of remaining customer web servers, directing the request from the user to the customer web server, receiving a request from the user for static content on the web page at a second web address, determining the point of presence server from the network of point of presence servers that is appropriate for the request, the point of presence server having service metrics more appropriate than service metrics of remaining point of presence servers from the network.

Abstract: A method and apparatus for establishing session persistence between a client and an origin server are provided. The session persistence can be managed by an intermediate cache server. The persistence is established by inserting an identifier and origin server address in a cookie or URL. Alternatively, the persistence is established by a table mapping a source IP address or a session ID to a specific origin server. Subsequent requests from the same client are mapped to the same origin server using these methods of establishing persistence.

Abstract: A method for determining metrics of a content delivery and global traffic management network provides service metric probes that determine the service availability and metric measurements of types of services provided by a content delivery machine. Latency probes are also provided for determining the latency of various servers within a network. Service metric probes consult a configuration file containing each DNS name in its area and the set of services. Each server in the network has a metric test associated with each service supported by the server which the service metric probes periodically performs metric tests on and records the metric test results which are periodically sent to all of the DNS servers in the network. DNS servers use the test result updates to determine the best server to return for a given DNS name. The latency probe calculates the latency from its location to a client's location using the round trip time for sending a packet to the client to obtain the latency value for that client.

Abstract: A method and apparatus for the automatic migration of data via a distributed computer network allows a customer to select content files that are to be transferred to a group of edge servers. Origin sites store all of a customer's available content files. An edge server maintains a dynamic number of popular files in its memory for the customer. The files are ranked from most popular to least popular and when a file has been requested from an edge server a sufficient number of times to become more popular than the lowest popular stored file, the file is obtained from an origin site. The edge servers are grouped into two service levels: regional and global. The customer is charged a higher fee to store its popular files on the global edge servers compared to a regional set of edge servers because of greater coverage.

Abstract: A method for operating a network of point of presence servers includes receiving a request from a user for a web page at a first web address, determining traffic loads of a plurality of customer web servers, determining a customer web server from the plurality of customer web servers, the customer web server having a traffic load lower than traffic loads of remaining customer web servers, directing the request from the user to the customer web server, receiving a request from the user for static content on the web page at a second web address, determining the point of presence server from the network of point of presence servers that is appropriate for the request, the point of presence server having service metrics more appropriate than service metrics of remaining point of presence servers from the network.

Abstract: A method for determining metrics of a content delivery and global traffic management network provides service metric probes that determine the service availability and metric measurements of types of services provided by a content delivery machine. Latency probes are also provided for determining the latency of various servers within a network. Service metric probes consult a configuration file containing each DNS name in its area and the set of services. Each server in the network has a metric test associated with each service supported by the server which the service metric probes periodically performs metric tests on and records the metric test results which are periodically sent to all of the DNS servers in the network. DNS servers use the test result updates to determine the best server to return for a given DNS name. The latency probe calculates the latency from its location to a client's location using the round trip time for sending a packet to the client to obtain the latency value for that client.