Abstract: The present invention provides for a method and apparatus for comparison of network systems using live traffic in real-time. The inventive technique presents real-world workload in real-time with no external impact (i.e. no impact on the system under test), and it enables comparison against a production system for correctness verification. A preferred embodiment of the invention is a testing tool for the pseudo-live testing of CDN content staging servers, According to the invention, traffic between clients and the live production CDN servers is monitored by a simulator device, which then replicates this workload onto a system under test (SUT). The simulator detects divergences between the outputs from the SUT and live production servers, allowing detection of erroneous behavior. To the extent possible, the SUT is completely isolated from the outside world so that errors or crashes by this system do not affect either the CDN customers or the end users. Thus, the SUT does not interact with end users (i.e.

Abstract: The present invention leverages an existing content delivery network infrastructure to provide a system that enhances performance for any application that uses the Internet Protocol (IP) as its underlying transport mechanism. An overlay network comprises a set of edge nodes, intermediate nodes, and gateway nodes. This network provides optimized routing of IP packets. Internet application users can use the overlay to obtain improved performance during normal network conditions, to obtain or maintain good performance where normal default BGP routing would otherwise force the user over congested or poorly performing paths, or to enable the user to maintain communications to a target server application even during network outages.

Abstract: An application deployment model for enterprise applications to enable applications to be deployed to and executed from a globally distributed computing platform, such as an Internet content delivery network (CDN). According to the invention, application developers separate their Web application into two layers: a highly distributed edge layer and a centralized origin layer. In a representative embodiment, the edge layer supports a servlet container that executes a Web tier, typically the presentation layer of a given Java-based application. Where necessary, the edge layer communicates with code running on an origin server to respond to a given request. In an alternative embodiment, the edge layer supports a more fully-provisioned application server that executes both Web tier (e.g., presentation) and Enterprise tier application (e.g., business logic) components.

Abstract: An application deployment model for enterprise applications to enable such applications to be deployed to and executed from a globally distributed computing platform, such as an Internet content delivery network (CDN). According to the invention, application developers separate their Web application into two layers: a highly distributed edge layer and a centralized origin layer. In a representative embodiment, the edge layer supports a servlet container that executes a Web tier, typically the presentation layer of a given Java-based application. Where necessary, the edge layer communicates with code running on an origin server to respond to a given request. In an alternative embodiment, the edge layer supports a more fully-provisioned application server that executes both Web tier (e.g., presentation) and Enterprise tier application (e.g., business logic) components.

Abstract: The present invention provides for a method and apparatus for comparison of network systems using live traffic in real-time. The inventive technique presents real-world workload in real-time with no external impact (i.e. no impact on the system under test), and it enables comparison against a production system for correctness verification. A preferred embodiment of the invention is a testing tool for the pseudo-live testing of CDN content staging servers, According to the invention, traffic between clients and the live production CDN servers is monitored by a simulator device, which then replicates this workload onto a system under test (SUT). The simulator detects divergences between the outputs from the SUT and live production servers, allowing detection of erroneous behavior. To the extent possible, the SUT is completely isolated from the outside world so that errors or crashes by this system do not affect either the CDN customers or the end users. Thus, the SUT does not interact with end users (i.e.

Abstract: An application deployment model for enterprise applications to enable such applications to be deployed to and executed from a globally distributed computing platform, such as an Internet content delivery network (CDN). According to the invention, application developers separate their Web application into two layers: a highly distributed edge layer and a centralized origin layer. In a representative embodiment, the edge layer supports a servlet container that executes a Web tier, typically the presentation layer of a given Java-based application. Where necessary, the edge layer communicates with code running on an origin server to respond to a given request. In an alternative embodiment, the edge layer supports a more fully-provisioned application server that executes both Web tier (e.g., presentation) and Enterprise tier application (e.g., business logic) components.

Abstract: An application deployment model for enterprise applications enables such applications to be deployed to and executed from a globally distributed computing platform, such as an edge server in an Internet content delivery network (CDN). In a representative embodiment, a CDN edge server supports application server code that executes a Web tier and/or Enterprise tier component of a given Java-based application. When multiple instances of the application server code are executed, given resources (e.g., memory, CPU, disk and network I/O) are monitored, and the application server instances are terminated or rate-limited to prevent over-utilization by any particular instance. In addition, a given application running in a given application server instance is restricted from taking certain actions, e.g., reading or writing from a file system, so that it cannot interfere with or access data from another customer's application.

Abstract: A data recording device including recording media having a set of at least two alternate regions thereon for each data segment, whereby each data segment has a corresponding set of at least two alternate regions on the recording media; a transducer positionable to write data on and read data from the recording media; and a controller for recording one or more data segments on the recording media in response to one or more write commands, the controller including a selector wherein for each of said one or more data segments the selector selects one region from the set of alternate regions corresponding to that data segment and positions the transducer to write that data segment on the selected region. To reduce the access time for each write operation, the selector selects the one region from the set of alternate regions based on shortest access time required to access each of the regions in the set of alternate regions for recording data.