Veritas Operating Corporation

Symantec Operating Corporation

Burton A Hipp

Emily Hipp

Yuh-yen Yeh

Rajeev Bharadhwaj

William C Romans

Carlos Wong

Yuh-Yen Yeh

A system or network may provide for communication between two or more applications. The communication is achieved by initiating communication between a first and second application. The communication is directed from the first application to a second virtual address of the second application. An actual address associated with the second application is determined. A first data channel is established between a first computer associated with the first application and a second computer associated with the second application over a control channel, to coordinate the communication over the first data channel. The communication is then directed to the actual address associated with the second application over the data channel. Further, the first data channel is taken down and a second data channel is established to maintain communication without the knowledge of the first and second applications.

Virtual endpoint

The present invention provides virtual mapping of system resource identifiers in use by a software application for the purpose of making the running state of an application node independent. By adding a layer of indirection between the application and the resource, new system resources are reallocated and then can be mapped to the application's existing resource requirements while it is running, without the application detecting a failure or change in resource handles. This layer of indirection makes the application's system resource identifier(system RID) transparent to the application. RID's are usually numeric in form, but can also be alphanumeric. RID's are unique to a machine, and can be reused once all claims to a specfic RID have been given up.

Virtual resource ID mapping

To achieve the foregoing, and in accordance with the purpose of the present invention, a system or network is disclosed which provides for a dynamic symbolic link (DSL) and the resolution of that DSL. The invention provides a method and apparatus that renames a first pathname to a target pathname, determines a variable within the target pathname, defines the first pathname as a symbolic link and associates the symbolic link with a virtual pathname. The present invention further defines a specification associated with the virtual pathname including associating the variable with the virtual pathname. In associating the symbolic link with the virtual pathname, the present invention further define a declaration within the virtual pathname.

Dynamic symbolic link resolution

A method, system and computer program product for creating a virtual network identity, by using a virtual IP address and hostname, in a software application for the express purpose of making the application node-independent (where node is defined as a particular machine running a given operating system at a specific moment in time) is disclosed. By virtualizing the IP address and hostname, a running software application can be moved from one node to another within a computer network, allowing for process migration and the reallocation of system resources.

IP virtualization

An overlay filesystem is described. The overlay filesystem is capable of accessing files from a first layer or a second layer based on one or more criteria. The overlay filesystem is also capable of saving changes made to any files in a different layer while preserving the original files in the original layer.

Method and system for an overlay filesystem

A virtual network environment to be used by a set of applications for the express purpose of isolating the applications from other applications on the same node or network is disclosed. The virtual network environment encapsulates a set of applications within a virtual network and prevents applications from interfering, either maliciously or unintentionally, with other applications outside of its virtual network environment. This virtual network environment provides security and network isolation between applications, as is required in a hosted application environment.

Virtual network environment

The present invention provides virtual mapping of system resource identifiers in use by a software application for the purpose of making the running state of an application node independent. By adding a layer of indirection between the application and the resource, new system resources are reallocated and then can be mapped to the application's existing resource requirements while it is running, without the application detecting a failure or change in resource handles. This layer of indirection makes the application's system resource identifier (system RID) transparent to the application. RID's are usually numeric in form, but can also be alphanumeric. RID's are unique to a machine, and can be reused once all claims to a specific RID have been given up.

A system, methods, and computer program products are disclosed for creating virtual application templates for the purpose of propagating a single application snapshot into multiple, distinct images. Snapshot virtual templates allow multiple application instances to use the same fixed resource identifier by making the resource identifier virtual, privatizing it, and dynamically mapping it to a unique system resource identifier. When a snapshot is cloned from a virtual template, the common or shared data is used exactly as is, whereas the non-sharable data is either copied-on-write, multiplexed, virtualized, or customized-on-duplication. The present invention notes access to modified resources, fixed system IDs/keys and unique process-related identifies and automatically inserts a level of abstraction between these resources and the application. The resources contained in a snapshot virtual template can be dynamically redirected at restore time. Access to memory and storage is managed in a copy-on-write fashion. System resource handles are managed in a virtualize-on-allocate fashion or by a multiplex-on-access mechanism. Process-unique resources are managed in a redirect-on-duplicate fashion. Rules may be defined through an application configurator that allows some degree of control over the creation of non-sharable data. The snapshot virtual template is constructed by dividing the snapshot image into sharable and non-sharable data. Knowledge of which system resources can be shared is encoded in the application snapshot/restore framework.

Snapshot image for the application state of unshareable and shareable data

To achieve the foregoing, and in accordance with the purpose of the present invention, a method and apparatus is disclosed which provides communication between at least two applications. The communication is achieved by accepting a connection from a second application on a first port and allocating a second port to receive the communication from the second application. Once the second port has been allocated the second port translation is recorded. The communication is sent to the first port from the second application and received on the second port. The communication is then delivered to a first application from the second port. In one embodiment the first application requests the communication from the first port and the first port is translated to determine the second port such that the communication is delivered to the first application in the step of delivering the communication to the first application.

Virtual port multiplexing

The present invention saves all process state, memory, and dependencies related to a software application to a snapshot image. Interprocess communication (IPC) mechanisms such as shared memory and semaphores must be preserved in the snapshot image as well. IPC mechanisms include any resource that is shared between two process or any communication mechanism or channel that allow two processes to communicate or interoperate is a form of IPC. Between snapshots, memory deltas are flushed to the snapshot image, so that only the modified-pages need be updated. Software modules are included to track usage of resources and their corresponding handles. At snapshot time, state is saved by querying the operating system kernel, the application snapshot/restore framework components, and the process management subsystem that allows applications to retrieve internal process-specific information not available through existing system calls. At restore time, the reverse sequence of steps for the snapshot procedure is followed and state is restored by making requests to the kernel, the application snapshot/restore framework, and the process management subsystem.

Growing community of inventors

Elk Grove, CA, United States of America

Burton A Hipp