Abstract: Systems and methods for providing a development and deployment platform for Software as a Service (SaaS) providers are disclosed. The platform may provide an application programming interface (API) through which customers may configure virtualized grids of language-level virtual machines (VMs), networks, and storage resources. A grid may be horizontally scalable and programmatically configurable by a customer and/or customer code. The platform may allow dynamic scaling of resources (up and down) to match changing demands, by allowing customers and/or customer code to programmatically alter their own system level structure at runtime, through the API. The grid may be accessed by both on-grid and off-grid processes, through internal and external connectivity resources provided by the platform. The platform may provide common utilities for end-user services, deployment operations, and development tasks (e.g., debugging), and may include frameworks and macro-components (e.g. web servers).

Abstract: Methods and apparatus provide for a Process Descriptor to obtain an identity of an entity controlling resources of a plurality of computer systems linked via a network which access a common set of network file systems. Via a process abstraction, the Process Descriptor allows a user to describe a run-time configuration for a process to be run with the entity. The entity instantiates an instance for the process of the first application according to the first run-time configuration. For each process described by the process abstraction, the process' run-time configuration includes one or more unique network address associated with the process and network file systems, from the common set of network file systems, accessible by the process. By associating a unique network address with the process, communication with that process' instance is available wherever the instance is executing within the entity.

Abstract: Systems and methods for providing a development and deployment platform for Software as a Service (SaaS) providers are disclosed. The platform may provide an application programming interface (API) through which customers may configure virtualized grids of language-level virtual machines (VMs), networks, and storage resources. A grid may be horizontally scalable and programmatically configurable by a customer and/or customer code. The platform may allow dynamic scaling of resources (up and down) to match changing demands, by allowing customers and/or customer code to programmatically alter their own system level structure at runtime, through the API. The grid may be accessed by both on-grid and off-grid processes, through internal and external connectivity resources provided by the platform. The platform may provide common utilities for end-user services, deployment operations, and development tasks (e.g., debugging), and may include frameworks and macro-components (e.g. web servers).

Abstract: A system consistent with the present invention reduces the number of redundant class descriptors that are sent during remote method calls by using serialization contexts. “Serialization contexts” are dictionary objects that map a class descriptor to a corresponding integer handle. When possible, the integer handle, rather than the full class descriptor, is passed, saving processing time in RMI calls.

Abstract: A homogeneous execution environment operates within a heterogeneous client-server network. A client selects a server and transmits a procedure call with parameters. In response, a server dynamically and securely downloads code to a compute server; invokes a generic compute method; executes the code on the compute server; and returns the results to the calling client method, preserving the result on the compute server if requested. This technique is efficient in that it does not require multiple copies of code to be downloaded or compiled since server byte-codes can be executed on each of the different systems, therefore downloading or compiling multiple copies of code can be avoided. The code can be compiled once and downloaded as needed to the various servers as byte-codes and then executed.

Abstract: A distributed computer system uses a single interface at the client site to handle calls to call both active and passive remote objects. Accordingly, the calling process does not need to be aware of distinctions between active and passive objects. Further, remote objects are aggregated into common groups of objects, thereby providing greater security between objects of disparate groups and efficiency between related objects of the same group. Preferably, different groups are run on different Java virtual machines.

Abstract: A system consistent with the present invention enables a program in a distributed system to determine whether downloaded code is trustworthy before using the downloaded code to communicate with other programs or services in the distributed system. A client that downloads proxy code from a service can verify that both the service and the downloaded code are trustworthy before using the code to communicate with the service. “Trustworthy” code is code the client knows will enforce the client's security constraints in communicating with the service, e.g., mutual authentication, confidentiality, and integrity.

Abstract: In an object-oriented data processing system, methods and systems in accordance with the present invention provide a proxy class dynamically generated at runtime that implements a list of interfaces specified at runtime such that a method invocation through an interface on an instance of the class is encoded and dispatched uniformly to an object that performs the invocation of the requested method. The generation of the proxy class at runtime and the specification at runtime of the list of interfaces implemented by the proxy class allow the interfaces to be used to be chosen at runtime before generation of the proxy class. Since the proxy class does not need to be created before compile time, the interface list implemented by the proxy class does not need to be known at the time the source code is written.

Abstract: A method and system is provided to uniquely identify a remote method to invoke on a server using a hash value computed from the method signature sent from the client to the server with the call request. When a client wishes to invoke a remote method located on a server, the client sends a hash value identifying the remote method to the server in the “remote method invocation” (RMI) call. In one implementation, this hash value is created by applying a hash function to the method string name and the parameter type list and possibly the return type. When the server receives the RMI call, the server identifies which method is being called using the received hash value. The server maintains a mapping of hash values to their associated remote methods located on the server and references the correct method using the hash value. Additionally, in one implementation, the server creates the mapping table dynamically when a remote object is created.

Abstract: Systems consistent with the present invention a method and apparatus is provided for selectively supplying a state change associated with remote objects in a distributed system. The method involves registering a request from a computational entity to receive notification as to a state change associated with a remote object. Registration of a notification request causes the creation of a remote weak reference to the remote object including an identifier of a location of the remote object. Periodically, a request is sent to a location based on the identifier of the remote weak reference. When it is determined that a state change associated with the remote object has occurred, the registered computational entity is notified accordingly.

Abstract: Downloading code for communicating with a device that joins a network. When the device joins the network, it transmits a multicast packet including a reference to code for use in communicating with the device. Receivers in the network use the reference to download the code for constructing objects to communicate with the device, and the receivers respond with a reference to a lookup service in the network. Using the reference from the receivers, the device registers with the lookup service.

Abstract: Remote method invocation using a generic proxy class. A client machine transmits a call for invocation of a method of a remote object including an identifier for the method object. A server machine receives the identifier and uses generic code to invoke the method object and return an indication of the invoked method along with any relevant parameters.

Abstract: In a distributed computing system, a first process may register interest in an event occurring in another address space or physical machine in such a way as to allow the subsequent notification of the event's occurrence to contain an object that includes methods that are to be run on receipt of the notification. When the notification is received, either by the first process or by some other entity designated by the first process to be the final point of notification, the methods may be executed as specified by the first process.

Abstract: A system consistent with the present invention reduces the number of redundant class descriptors that are sent during remote method calls by using serialization contexts. “Serialization contexts” are dictionary objects that map a class descriptor to a corresponding integer handle. When possible, the integer handle, rather than the full class descriptor, is passed, saving processing time in RMI calls.

Abstract: A homogeneous execution environment operates within a heterogeneous client-server network. A client selects a server and transmits a procedure call with parameters. In response, the system dynamically and securely downloads code to a compute server; invokes a generic compute method; executes the code on the compute server; and returns the results to the calling client method, preserving the result on the compute server if requested. This technique is efficient in that it does not require multiple copies of code to be downloaded or compiled since server byte-codes can be executed on each of the different systems. The code can be compiled once and downloaded as needed to the various servers as byte-codes and then executed.

Abstract: Event notification in a distributed system using an object maintained in serialized form, referred to as a marshalled object. For event notification, a machine registers with a device to receive notification of particular events within a network, and a marshalled object is transmitted with a registration request.

Abstract: Disclosed is a single mode optical waveguide fiber having a core refractive index profile in which the profile parameters are selected to provide an attenuation minimum. A set of profiles having the same general shape and dimensions is shown to have a group of profiles contained in a sub-set which exhibit a minimum of attenuation as compared to the remaining members of the set. The members of the sub-set have been found to have the lowest effective group index, ngeff, and the lowest change in &bgr;2 under waveguide fiber bending.

Abstract: In a distributed computing system, a first process may register interest in an event occurring in another address space or physical machine in such a way as to allow the subsequent notification of the event's occurrence to contain an object that includes methods that are to be run on receipt of the notification. When the notification is received, either by the first process or by some other entity designated by the first process to be the final point of notification, the methods may be executed as specified by the first process.

Abstract: In a client-server environment it would be desirable to have a number of servers capable of processing a broad range of applications such as compute intensive applications or graphic operations such as rendering. In a heterogeneous client-server environment, conventional systems statically stored executables on a server for later execution. This required extensive storage as well as many programmer hours porting applications to the server machine from client machines which had different object modules. This invention solves these problems by creating a homogeneous execution environment within a heterogenous client-server network. Accordingly, this system dynamically downloads code on a compute server, executes the code on the compute server, and returns the results to the calling client method. This technique does not require multiple copies of code to be downloaded nor compiled since the server code can be executed on all the different systems.

Abstract: Disclosed is a single mode optical waveguide fiber having a core refractive index profile in which the profile parameters are selected to provide an attenuation minimum. A set of profiles having the same general shape and dimensions is shown to have a group of profiles contained in a sub-set which exhibit a minimum of attenuation as compared to the remaining members of the set. The members of the sub-set have been found to have the lowest effective group index, ngeff, and the lowest change in &bgr;2 under waveguide fiber bending.