International Business Machines Corporation

Convergys Cmg Utah Inc.

Trilogy Development Group, Inc.

Whisperwire, Inc.

Ahmed Gheith

Patrick Joseph Bohrer

James Xenidis

Ramakrishnan Rajamony

Kanak Behari Agarwal

Michael D Kistler

Eric Van Hensbergen

Brian Lee White Eagle

Aditya Kumar

James Lyle Peterson

Ronald Lynn Rockhold

Tracy James Bashore

Andrew R Malota

Elmootazbellah Nabil Elnozahy

Andrew James Declercq

Charles Erickson

Rod Mancisidor

Karthick Rajamani

Lixin Zhang

William Evan Speight

John Bruce Carter

William Chan

Volker Strumpen

Matteo Frigo

Eric Van Hansbergen

Yu Zhang

Hua Wang

Balaram Sinharoy

Kun Wang

Peter H Hochschild

Hazim Shafi

Richard Ormond Simpson

Rob Norris

A request to access to a logical location in a file stored in a content addressable storage (CAS) system can be processed by retrieving first tree data from a first node in a first hash tree that represents a first version of the file. Based on the first tree data, a second node is selected from which a CAS signature is compared to a reserved CAS signature to determine the proper file version. In response to a match, a third node is accessed in a second hash tree that represents a second version of the file. Tree data is retrieved from a third node.

File versions within content addressable storage

A request to access to a logical location in a file stored in a content addressable storage (CAS) system can be handled by retrieving first tree data from a first node in a hash tree that represents the file, the first tree data including a first hash tree depth, a first CAS signature, a block size and a file size. Based on the tree data, a second node is selected from a higher level in the hash tree. Second tree data from the second node of the hash tree that represents the file is retrieved, including a second CAS signature. The second CAS signature is determined to match a reserved CAS signature, and in response, an indication that the requested logical location is unallocated within the file is provided.

Files having unallocated portions within content addressable storage

For location-based communication with mobile devices, a set of callee conditions is received at a caller's device, which has to be satisfied by a callee according to information descriptive of a condition of the callee. The state information is distinct from the location and a time of the callee's presence at the location. An evaluation is made that each device associated with each potential callee in a first subset has been present at the location at a specified time, and that each potential callee in the first subset satisfies the set of callee conditions. At the caller's device, an instruction is received for making a telecommunication call to a device of a potential callee in a first subset. The call is initiated from the caller's device to mobile devices associated with the first subset of potential callees.

Callee condition based communication with mobile devices

A method, system, and computer program product for scalable and self-healing architecture for client-server operations in transient connectivity conditions are provided in the illustrative embodiments. An application in a second system receives a request from a first system, the request requesting data from a type of service. A first response responds to the request. The request is queued in a service queue corresponding to the type of the service, to make the request available to a third system that provides the type of the service. A notification is received that a second response from the third data processing system has been posted into a session specific queue, the second response being responsive to the request. In response to another request received from the first system, a third response is sent to the first system, the third response including the data from the second response from the session specific queue.

Scalable self-healing architecture for client-server operations in transient connectivity conditions

A dynamic data distribution system allows publication of data values for hierarchical keys (paths) and subscriptions to key (path) patterns which include wildcard characters. Permission to publish or subscribe is controlled by an access control list associated with each key. An agent receives a publication request from a client, verifies client access permissions on the subject key, and transmits the publication to a data storage server which performs the write. Following a successful write, the agent forwards the publication to a message routing exchange which routes the publication to the session queue for all clients that are permitted to receive the publication and have subscribed to a key pattern matching this publication. For data synchronization, the data storage server assigns a virtual time stamp to each write, and the subscriber verifies the count of updates received for a subscription within a sliding window of virtual time stamps.

Dynamic distribution of persistent data

A method for managing data access in a mobile device is provided in the illustrative embodiments. Using a data manager executing in the mobile device, a data item is configured in a data model. A value parameter of the data item is populated with data and a status parameter of the data item is populated with a status indication. A subscription to the data item is received from a mobile application executing in the mobile device. In response to the subscription, the data and the status of the data item are sent to the mobile application.

Managing data access in mobile devices

To provide client-side fault-tolerance in a publish-subscribe system, a message is received on a channel from a server. At a function executing using a processor and a memory, a determination is made whether the message contains a heartbeat data. When the message contains the heartbeat data, a determination is made whether a content signature contained in the message matches a last known content signature saved from a previous message. When the content signature contained in the message does not match the last known content signature saved from a previous message, a refresh message is sent to the channel.

Client-side fault tolerance in a publish-subscribe system

A simulation technique that handles accesses to a frame of memory via a proxy object provides improved throughput in simulation environments. The proxy object, if present, processes the access at a head of a linked list of frames. If a check frame is not inserted in the list, the memory frame handles the request directly, but if a check frame is inserted, then the check operation is performed. The check frame can be a synchronization frame that blocks access to a memory frame while the check frame is present, or the check frame may be a breakpoint, watch or exception frame that calls a suitable handling routine. Additional check frames may be chained between the interface and the memory subsystem to handle synchronization, breakpoints, memory watches or other accesses to or information gathering associated with the memory frame.

Memory frame proxy architecture for synchronization and check handling in a simulator

Simulation method using memory frame proxy architecture for synchronization and check handling

To manage channel ownership in a publish-subscribe data processing environment, a determination is made at a first server that a subscription request from a client relates to a channel, the channel having a channel identifier. At an exchange component in a messaging middleware, a session queue associated with the client is bound to the channel. A mandatory delivery message is configured to be routed using a publisher identifier by the exchange component, the publisher identifier being related to the channel identifier. The mandatory delivery message is communicated from the first server to the exchange component to indicate an intent of the first server to become a publisher of the channel. The mandatory delivery message causes the channel ownership of the channel to be limited to a single publisher.

Channel ownership in a publish-subscribe system

A system, and computer usable program product for fast remote communication and computation between processors are provided in the illustrative embodiments. A direct core to core communication unit (DCC) is configured to operate with a first processor, the first processor being a remote processor. A memory associated with the DCC receives a set of bytes, the set of bytes being sent from a second processor. An operation specified in the set of bytes is executed at the remote processor such that the operation is invoked without causing a software thread to execute.

Fast remote communication and computation between processors using store and load operations on direct core-to-core memory

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Austin, TX, United States of America

Ahmed Gheith