Microsoft Technology Licensing, LLC

Hewlett-packard Development Company, L.P.

Digital Equipment Corporation

Compaq Information Technologies Group, L.p.

Microsoft Corporation

Thomas Lee Rodeheffer

Gopala Krishna R Kakivaya

Richard L Hasha

Mark David Lillibridge

Chandramohan Amyangot Thekkath

Edward Pearce Wobber

Yuan Yu

Martin Abadi

Douglas Brian Terry

Charles Patrick Thacker

Lidong Zhou

Vijayan Prabhakaran

Darrell Anderson

Venugopalan Ramasubramanian

Fang Yu

Andreas Georg Nowatzyk

Andrew David Birrell

Leslie B Lamport

Raymond Paul Stata

Erwin Oertli

Ramakrishna Rao Kotla

Roger Michael Needham

Hallam G Murray, Jr

K Mani Chandy

Michael D Schroeder

Edwin H Satterthwaite, Jr

Meg Walraed-Sullivan

Gopala Krishna Kakivaya

A machine-implemented method includes automatically determining that a host device is restarting from a disruptive stoppage of operations and that in-process write transactions by the host device to respective pages of non-volatile storage may have been interrupted. The method includes, in response to the determination, automatically scanning the non-volatile storage for all metadata-containing storage pages with respective identifications S(i) and having corresponding metadata relating each respective storage page S(i) to a corresponding data page P(j) and a corresponding version number V(k). The method includes automatically identifying scanned storage pages S(i) that have for their corresponding data page P(j) a most recent version number HV(k) and, in some cases, a secondmost recent version number. The method includes designating for expungement scanned storage pages S(i) that are not both of committed and having the more recent of the most recent and secondmost recent version number for their corresponding data structure page P(j).

Cyclic commit transaction protocol

A cyclic commit protocol is used to store relationships between transactions and is used by the technology to determine whether a transaction is committed or not. The protocol allows creation of a cycle of transactions which can be used to recover the state of a storage device after a host failure by identifying the last committed version of intention records as committed or uncommitted based on the data stored in the physical pages.

A circuit-based digital communications network is provided for a large data center environment that utilizes circuit switching in lieu of packet switching in order to lower the cost of the network and to gain performance efficiencies. A method for transmitting data in such a network comprises sending a setup request for a path for transmitting the data to a destination node and then speculatively sending the data to the destination node before the setup request is completed.

Data center network using circuit switching

A cryptographically-secure component provides access-undeniability and verifiable revocation for clients with respect to downloaded content items from a server. A cryptographically-secure component is implemented in a client. When the client wants to purchase and download a content item from the server, the server requests an encryption key from the client. The client generates an encryption key that is bound to a state of the client that is associated with decrypting the content item. The server encrypts the content item using the encryption key and sends the encrypted content item to the client. Because the encryption key used to encrypt the content item is bound to the state associated with the client decrypting the content item, if the client desires to view the content item the client may first advance its state to the bound state to retrieve the decryption key.

Offline data access using trusted hardware

A system is disclosed for creating and implementing an access control policy framework in a weakly coherent distributed collection. A collection manager may sign certificates forming equivalence classes of replicas that share a specific authority. The collection manager and/or certain privileged replicas may issue certificates that delegate authority for control of item policy and replica policy. Further certificates may be signed that create one or more items, set policy for these one or more items, and define a set of operations authorized on the one or more items. The certificates issued according to the present system for creating and implementing a control policy framework cannot be modified or simply overridden. Once a policy certificate is issued, it may only be revoked by the collection manager or by a replica having revocation authority.

Access control policy in a weakly-coherent distributed collection

Methods, systems and computer program products are provided for rendezvousing resource requests with corresponding resources. Doubly linked sorted lists are traversed using modulo arithmetic in both directions. Sorted lists can be partitioned based on a multiple proximity metrics. Node routing tables provide a logarithmic index to nodes within the ID space of the federation infrastructure to facilitate more efficient routing. Messages can be routed to nodes within a ring and proximally routed to nodes in other partitioned rings.

Rendezvousing resource requests with corresponding resources

A distributed system includes full and partial replicas of a set of data items that may be inserted, modified, or deleted by any replica. Replicas may occasionally synchronize with other arbitrarily chosen replicas to learn about updates. A replica's knowledge includes one or more knowledge fragments, where each fragment indicates a set of items. A type of knowledge fragment, called a star knowledge fragment, contains versions associated with all items in the system. Star knowledge fragments are compact because the set of items stored at a replica need not be explicitly listed. Once all replicas know of all updates in the system, partial and full replicas will have the same compact star knowledge fragment.

Accumulating star knowledge in replicated data protocol

The present invention extends to methods, systems, and computer program products for rendezvousing resource requests with corresponding resources. Doubly linked sorted lists are traversed using modulo arithmetic in both directions. Sorted lists can be partitioned based on a multiple proximity metrics. Node routing tables provide a logarithmic index to nodes within the ID space of the federation infrastructure to facilitate more efficient routing. Messages can be routed to nodes within a ring and proximally routed to nodes in other partitioned rings.

A method and apparatus are provided for detecting data races that overcome the limitations of the prior art. In some embodiments, this is accomplished by detecting a first access to an object, determining whether the first access is associated with a suspicious pattern, automatically refining a pattern detection granularity from the object to a memory location within the object if a determination is made that the first access is associated with the suspicious pattern, and reporting the data race if a second access associated with the suspicious pattern occurs at the memory location after the pattern detection granularity is refined.

Adaptive granularity refinement in detecting potential data races

A system is disclosed for synchronizing partially-replicated collections using the concept of item-set knowledge and move-out notifications. Move-out notifications are provided to allow removal of changed items from replicas when the change in the item takes that item outside of the interest set of the replicas.

Move-in/move-out notification for partial replica synchronization

The present invention extends to methods, systems, and computer program products for establishing and maintaining membership within a federation infrastructure. A joining node submits a join message to an existing federation infrastructure. The federation infrastructure routes the join message to a processing node. The processing node facilitates identification of predecessor, successor, neighborhood, and routing nodes (for the joining node) within a ring of nodes. The joining node exchanges messages with identified nodes to obtain state information for the identified nodes and other nodes within the ring. Nodes periodically exchange state information, including state information for other nodes, such that state information for the ring is efficiently propagated to all nodes in the ring even when communication between some nodes is lost. Instance IDs, phase values, and freshness values are used to determine when state information is stale and/or is to be updated.

Establishing membership within a federation infrastructure

Criteria are defined for determining when additional stack dumps would be saved and presented (e.g., to the developer). This provides more information for the developer to use for debugging, and yet does not overburden the developer with irrelevant information. Suspicious activity worthy of an additional stack dumps may be defined as a thread accessing an already suspicious location that is different than the original thread, a write access being made and no write access having yet been made to the target location, or if the lockset being held by the thread accessing the location is omitted from the intersection of all locksets involved in stack dumps for the location.

Systems and methods of reporting multiple threads involved in a potential data race

A network includes multiple segments and bridges interconnecting the segments, with hosts coupled to the segments. The bridges are smart bridges that each perform a host location initialization function. The host location initialization function in one bridge is performed in corporation with all other bridges in the bridged network via an instance through a propagation order spanning tree (POST). The initialization method includes obtaining prior host location information which is at least a partial representation of the host locations in the bridged network before the network topology change, obtaining hints on host location changes resulting from the network topology change, and modifying the prior host location information according to the hints to construct host location information for initialization. Location information for at least a portion of the hosts in the bridged network is preserved or discovered quickly each time when the network topology changes.

Growing community of inventors

Mountain View, CA, United States of America

Thomas Lee Rodeheffer