Abstract: Techniques for constructing a software application are provided. A data model of the application is represented as a relational model. Control logic of the application is defined as a mapping from a current state of the application data model and one or more application inputs to a new state of the application data model and one or more application outputs, described by relational algebra components.

Abstract: A method, system and computer program product for compressing state changes to a datum in a primary data storage system. One embodiment of the invention involves receiving a first state-change entry describing at least a first transformation of the datum and an first value of the datum and receiving a second state-change entry describing at least a second transformation of the datum an a second value of the datum. The first and second state-change entries are reduced to a compressed state-change entry including a compressed transformation and a compressed value that are functionally equivalent applying the first transformation and first value, then applying the second transformation and second value, to the datum. The techniques of the invention may be utilized, for example, in redo and undo database replication operations.

Abstract: One embodiment of the present method and apparatus for synchronization of client transactions executed by an autonomous client enables a client operating on a limited connection to a server to log transactions executed against a locally stored server database state. Logged transactions are then synchronized with a current server database state by delivering the transaction log to the server, which re-executes each logged client transaction against the current server database state, thereby reducing synchronization-related transaction conflicts.

Abstract: Methods and apparatus for dynamic runtime partitioning of network-based client/server applications using a Model-View-Controller pattern are provided. Such dynamic partitioning is accomplished by requiring that the application specify: (i) that access to the Model be done through an application programming interface (API) which allows the system runtime to dynamically allocate and access Model storage on the client and/or server; and (ii) that access to the View be done through an API which allows the system runtime to dynamically allocate and access View components on the client and/or server. This enables applications written and tested in such a manner (referred to herein as the “canonical form”) to execute in a non-distributed mode or in a dynamically partitioned mode in which client/server issues are not a factor. This greatly facilitates development of the application.

Abstract: A server allocation controller provides an improved distributed data processing system for facilitating dynamic allocation of computing resources. The server allocation controller supports transaction and parallel services across multiple data centers enabling dynamic allocation of computing resources based on the current workload and service level agreements. The server allocation controller provides a method for dynamic re-partitioning of the workload to handle workload surges. Computing resources are dynamically assigned among transaction and parallel application classes, based on the current and predicted workload. Based on a service level agreement, the server allocation controller monitors and predicts the load on the system. If the current or predicted load cannot be handled with the current system configuration the server allocation controller determines additional resources needed to handle the current or predicted workload. The server cluster is reconfigured to meet the service level agreement.

Abstract: An on-demand manager provides an improved distributed data processing system for facilitating dynamic allocation of computing resources among multiple domains based on a current workload and service level agreements. Based on a service level agreement, the on-demand manager monitors and predicts the load on the system. If the current or predicted load cannot be handled with the current system configuration, the on-demand manager determines additional resources needed to handle the workload. If the service level agreement violations cannot be handled by reconfiguring resources at a domain, the on-demand manager sends a resource request to other domains. These other domains analyze their own commitments and may accept the resource request, reject the request, or counter-propose with an offer of resources and a corresponding service level agreement.

Abstract: Techniques are provided which enable relaxed transactional isolation and optimistic concurrency control in a distributed client-server architecture, and which address the problems of server overloading and network delays known to exist in conventional distributed client-server architectures. In particular, the invention preferably provides client-side caching techniques which advantageously serve to reduce server overloading and effects of network delay.

Abstract: A method for manipulating objects in isolation, in accordance with the invention, includes providing a shared object, B, from an object provider for use on a distributed object system. A new class of objects are provided which include a facade object, Bf, for B and a versionable representation object, Bv, for B wherein Bf supports a same interface as B. B is permitted to be manipulated in a given context isolated from other contexts for the object B wherein the object provider and an object user are unaware of the production and manipulation of the new class of objects. Method invocations on Bf in the given context are delegated to Bv to associate an instance of Bv with the given context such that one or more versions of object B are persistently maintained in the distributed object system.

Abstract: A method for programming and executing long running transactions between interface devices and a server includes the steps of providing a predicate set and a transform set on the interface devices pursuant to an activity to be performed by the long running transaction, the predicate set defining conditions for which updates to states in accordance with the activity are to be made and the transform set for applying the updated states pursuant to the predicate set, committing the activity for processing upon establishment of communication with the server from the interface device, establishing communication with the server from the interface device to initiate the long running transaction, replaying the predicate set and the transform set for the server to determine if the long running transaction is capable of being committed on the server and if capable of being committed on the server, committing the long running transaction to update states of the server wherein a plurality of interface devices are capable

Abstract: In a data processing environment where a client requests a server to perform part of its processing, a method of updating the client's version of server-related data without requiring the client to be a server, includes steps of: receiving, at a control point server, a first request from the client requesting that server-related data be transferred from the control point server to the client; and in response to the first request, sending the server-related data from the control point server to the client, along with a unique bind token identifying a version number of the server-related data such that each time the server-related data changes a new unique bind token is associated with the data, where the client uses the server-related data to form a second request for the server to perform part of the client's processing, and where the client sends said bind token to the server as part of the second request.

Abstract: A method of performing workload management within an object-oriented client/server computing environment wherein one of a plurality of servers is chosen to satisfy a client request based on at least one workload management policy, said method, which takes place within the client, includes steps of: deciding whether a client application program has issued a request for a server to do some work; forming an extended object reference based on said request, said extended object reference having, in addition to a server address field and an object key field, at least one additional field; accessing workload management policy data based on said extended object reference; and selecting one of said plurality of servers based on said accessed workload management policy data.

Abstract: A system and method for a general and extensible infrastructure providing monitoring and recovery of interdependent systems in a distributed/clustered system is disclosed. Subsystems, built without provision for high availability, are incorporated into the infrastructure without modification to core subsystem function. The infrastructure is comprised of one or more computing nodes connected by one or more interconnection networks, and running one or more distributed subsystems. The infrastructure monitors the computing nodes using one or more heartbeat and membership protocols, and monitors the said distributed subsystems by subsystem-specific monitors. Events detected by monitors are sent to event handlers. Event handlers process events by filtering them through activities such as event correlation, removal of duplicates, and rollup.