Abstract: A service discovery protocol may allow clients to discover services on a proximity basis. A service device that provides one or more computing services may support a proximity communication link. A client device may form a proximity communication link with the service device. The client device may directly request from the service device a document that describes an interface to access a service provided by the service device. The service device may provide the document directly to the client device over proximity communication link. The document may include a service advertisement for the service, and the service advertisement may include a schema specifying an interface to at least a portion the service. The client device may use the information from the document to access the service. The client device may support a transport connection in addition to the proximity communication link, and the client device may make the document available to other devices over the transport connection.

Abstract: A system and method for providing an open network computing platform designed for peer-to-peer computing. The peer-to-peer platform may provide protocols for peer-to-peer services and applications that allow peers to discover each other, communicate with each other, and cooperate with each other to form peer groups. The protocols may include a peer membership protocol, a peer discovery protocol, a peer resolver protocol, a peer information protocol, a pipe binding protocol, and a peer endpoint protocol. Services and applications that participate in the protocols may be provided to deal with higher-level concepts. Advertisements may be used to publish peer resources. The peer-to-peer platform provides the ability to replicate information toward end users and may enable peers to find content that is closest to them. The peer-to-peer protocols and unique peer identifiers may allow peer nodes to move to different locations and access services and other content independent of network physical addresses.

Abstract: A system and method for uniquely identifying peers and other resources in a peer-to-peer networking environment. In one embodiment, every peer in the peer-to-peer network may have a unique peer identifier. Other peer-to-peer network resources may also have unique identifiers, including peer groups, services, applications, pipes, endpoints, content and resource advertisements. Identifiers may serve to canonically refer to resources. Identifiers may be embedded in advertisements for resources. In one embodiment, a peer identifier may identify a peer group in which the peer is a member peer. In one embodiment, a peer may have a different peer identifier for each group in which it is a member peer. In one embodiment, an identifier may be bound to a network address of the resource. If the resource changes network addresses, the identifier may be bound to the new network address. Thus, identifiers provide dynamic addressing for resources in the peer-to-peer environment.

Abstract: A distributed computing environment may employ spaces to provide a rendezvous mechanism that brokers services or content to clients. Services may advertise themselves in a space. Clients may find the advertisements in a space and use the information from an advertisement to access a service using a messaging mechanism. A space discovery protocol may be provided to find a space. A client may instantiate a discovery service to locate spaces. A listener agent may be configured associated with one or more spaces to listen for discovery requests. The listener agent may listen on various network interfaces, and may receive requests from clients looking for a space(s). The listener agent then responds with the service advertisement(s) or URIs for the service advertisements of the requested space(s). In one embodiment, the listener agent may be separate from the space and its functionality orthogonal to the functionality of the space.

Abstract: A system and method for providing peer groups in a peer-to-peer environment. A peer group may be one or more peers in a peer-to-peer environment that share a set of network services and content. A peer group may define an implicit scope for messages originating from members peers of the peer group. A peer group may provide redundant services and content for greater reliability. In one embodiment, interaction among peers and peer groups in the peer-to-peer environment may be implemented using protocols that are platform-independent as to programming language implementations and network transports. In one embodiment, peers may discover existing peer groups and join the existing peer groups. In one embodiment, peers may create new peer groups.

Abstract: Embodiments of a shared resource distributed index mechanism that peers in a peer-to-peer network may utilize to distribute index entries corresponding to resources to indexes of shared resources among one or more other peers. These indexes may be used to direct queries to peers where the queries are most likely to be answered. When a query is received by a rendezvous peer including one or more indexes, contents of the query may be “looked up” in the index to find matches. The results of the lookup may include information on one or peer(s) that may hold advertisement(s) to the resource requested by the query. The query may then be forwarded to one or more peers that may hold the advertisement for the resource. Embodiments may provide “loosely-coupled” distribution of index entries for use in querying for resources in the peer-to-peer network.

Abstract: A system and method for providing message-based leasing of resources in a distributed computing environment. Services may issue leases to clients and provide operations on those leases. The lease functionality of a service may be defined in an XML message schema. Gates may be used to perform lease operations. Leases may be granted for a period that may be negotiated. Leasing messages for performing leasing operations may be defined. An automatic lease renewal mechanism may be implemented to relieve the client of the responsibility of handling lease renewal messages. In one embodiment, of an automatic lease renewal mechanism, each gate may receive renewal messages and automatically respond to them without help from the client process. In another embodiment, a client gate may monitor elapsed time and send a lease renewal message prior to the expiration of a current lease period. In one embodiment, the renewal request may claim the lease at a current access level or at a different access level.

Abstract: A secure interface between clients and services in a distributed computing environment is described. Method gates may provide an interface to remotely invoke functions of a service. A method gate may be generated from an advertisement that may include definitions for one or more messages for remotely invoking functions of the service. A client may generate messages containing representations of method calls. The service may invoke functions that correspond to the set of messages. A method gate on the service may unmarshal the message and invoke the function. The client may receive the results of the function directly. Alternatively, the results may be stored, an advertisement to the results may be provided, and a gate may be generated to access the results. Message gates may perform the sending and receiving of the messages between the client and service. In one embodiment, functions of the service may be computer programming language (e.g. Java) methods.

Abstract: A system and method for providing rendezvous nodes in a peer-to-peer networking environment is described. Rendezvous nodes preferably cache information about network resources that may be useful to peer nodes on a peer-to-peer network. In one embodiment, a network of rendezvous nodes may help peer nodes to discover network resources over long-range on the peer-to-peer network. Network resource may include, but may not be limited to peer nodes, peer groups, services, content, and communication channels. In one embodiment, rendezvous nodes may respond to discovery query messages from peer nodes. The discovery query messages may specify desired network resource information. In one embodiment, rendezvous nodes may provide route discovery for network resources. In one embodiment, a peer node may be pre-configured with a pre-defined set of rendezvous nodes to access on startup. These bootstrapping rendezvous may help the peer node discover network resources that it needs to start up.

Abstract: Embodiments of a decentralized mechanism for detecting the presence of entities in a peer-to-peer network. In one embodiment, using pipes, a peer may uniquely and independently generate an identity for a peer-to-peer network entity. The identity may be used to probe the peer-to-peer network for presence of instances of the corresponding entity on other peers regardless of which peer the identity was generated on and without using a central identity repository or presence system. In one embodiment, net crawling may be used to map identities and resolve the locations of instances of the corresponding entities. An entity may move anywhere on the network, and the decentralized mechanism for detecting entity presence may be used to locate the instance(s) of the entity.

Abstract: A system and method for establishing communications channels between and among peers in a peer-to-peer networking environment. Pipes may be used as communication channels for sending and receiving messages and other data between services or applications over input and output endpoints. Pipes may be asynchronous, unidirectional, stateless and unreliable. Bidirectional pipes may also be supported. Pipes may have ends that may be moved around and bound to different peers at different times. Point-to-point and propagate pipes may be supported. Pipes may connect peers that have a direct physical link and peers that do not have a direct link. Peers may communicate through pipes without knowing on which peer a pipe endpoint is bound. A message is sent to all peer endpoints currently connected (listening) to the pipe. The set of connected endpoints may be obtained from a pipe service using a pipe binding protocol.

Abstract: System and method for the dynamic and transparent migration of services in a peer-to-peer networking environment. Member peers in a peer group using a peer-to-peer platform may cooperate to provide redundant instances of services to member peers. Dynamic migration of a service may be performed by unbinding one or more peer-to-peer platform pipes from a peer hosting an instance of the service and binding the pipes to another peer hosting a different instance of the service. Using pipes, services may transparently failover from one physical peer endpoint to another in order to mask a service or peer failure, or to access a newly published instance of a service. Thus, a collection of peers may provide a high level of fault tolerance, where, for example, a new peer at a different location may replace a crashed peer, with the new peer taking over the existing pipe to keep the communication going.

Abstract: A system and method for sending, resolving, and receiving queries for information on the status of network resources. A peer computing system may include one or more resolver nodes on a network for resolving queries for a resource to particular resource instances. The resolver nodes may receive query messages from peer nodes on the network. Each query message may request information about a resource implemented by one or more peer nodes on the network. The query messages may be formatted in accordance with a peer resolver protocol. The resolver node may determine a particular instance of the resource hosted on a particular peer node to receive the query. The resolver node may use a variety of criteria to determine a particular resource instance. The resolver node may forward the query message to the determined resource instance.

Abstract: A system and method for interaction and access to shared content among clients and services in a distributed computing environment. A client may access a space service. The space service may store one or more XML service advertisements and/or other XML content in a space, and each of the service advertisements may include information which is usable to access and execute a corresponding service. The space service may include an XML schema which specifies one or more messages usable to invoke functions of the space service. For example, the schema may specify methods for reading advertisements from the space and publishing advertisements in the space. In accessing the space service, the client may send information such as an XML message (as specified in the schema) to the space service at an Internet address. In accessing the space service, the client may search the one or more service advertisements stored in the space. The client may select one of the service advertisements from the space.

Abstract: A system and method for providing resources to networked devices for participating in a peer-to-peer environment. In one embodiment, a peer computing system on a network may include one or more bootstrap nodes that may provide, to devices coupled to the network, mechanisms for accessing resources for participating in the peer-to-peer environment. The bootstrap nodes may be peer nodes. The resources may give the devices access to services each of which may implement peer-to-peer platform protocols. The devices may be pre-configured to access one or more predefined peer nodes for information on bootstrap nodes. Alternatively, devices may use a bootstrapping mechanism to locate bootstrap nodes on the network.

Abstract: A virtual heap for a process executing within a virtual machine is described. In one embodiment, the virtual persistent heap may allow the running of an application on a physical heap that is smaller than may otherwise be required. As an example, the virtual persistent heap may be an order of magnitude larger than the physical, in-memory heap. This feature is important for small consumer and appliance devices, as these devices may have a limited amount of memory. In one embodiment, the virtual heap may be maintained on non-volatile memory storage external to the device running the virtual machine, and portions of the heap for the current execution state of the process may be cached in and out of a “physical” heap resident in local memory on the device. For example, the device may connect to a server on the Internet, and the server may provide non-volatile storage space for the virtual heap.

Abstract: A system and method for providing message-based leasing of resources in a distributed computing environment. Services may issue leases to clients and provide operations on those leases. The lease functionality of a service may be defined in an XML message schema. Gates may be used to perform lease operations. Leases may be granted for a period that may be negotiated. Leasing messages for performing leasing operations may be defined. The leasing messages may include messages to renew a lease and to cancel a lease. Services may specify an address where leasing messages may be sent. A lease renewal mechanism may be provided in which a gate may receive lease renewal messages and automatically respond to them. A mechanism to detect stale advertisements in a space may be provided. When a service publishes its advertisement in a space, the service obtains a lease on the publishing of its advertisement. Each advertisement may include a time by which the service may renew the advertisement.

Abstract: Various embodiments of a mechanism for a client to specify a display service to be used by a service for displaying data for the client in a distributed computing environment are described. A display service on or associated with the device on which the client resides that the client wishes to use to display the results of the service. When the client runs the service, the client may send a message to the service specifying the service advertisement of the client's display service. The service may then generate a message channel that allows it to send messages to the client's display service. Thus, when displaying results, the service invoked by the client becomes a client of the client's display service and sends its results, directly or by reference, for display to that display service.

Abstract: A caching mechanism for a virtual persistent heap. A feature of a virtual persistent heap is the method used to cache portions of the virtual persistent heap into the physical heap. The caching mechanism may be effective with small consumer and appliance devices that typically have a small amount of memory and that may be using flash devices as persistent storage. In the caching mechanism, the virtual persistent heap may be divided into cache lines. A cache line is the smallest amount of virtual persistent heap space that can be loaded or flushed at one time. Caching in and caching out operations are used to load cache lines into the heap or to flush dirty cache lines into the store. Different cache line sizes may be used for different regions of the heap. Translation between a virtual persistent heap address and the heap may be simplified by the caching mechanism.

Abstract: A method and system for performing generational garbage collection on a virtual heap in a virtual machine is provided. The garbage collection method is suited for use with small consumer and appliance devices that have a small amount of memory and may be using flash devices as persistent storage. The garbage collection method may provide good performance where only a portion of the virtual heap may be cached in the physical heap. The virtual heap may use a single address space for both objects in the store and the in-memory heap. In one embodiment, a single garbage collector is run on the virtual heap address space. The garbage collection method may remove non-referenced objects from the virtual heap. The garbage collection method may also include a compaction phase to reduce or eliminate fragmentation, and to improve locality of objects within the virtual heap.