Microsoft Technology Licensing, LLC

Microsoft Corporation

Thomas Ewan Jolly

David Matthew Kruse

James T Pinkerton

Mathew George

Prashanth Prahalad

Roopesh C Battepati

Daniel Edward Lovinger

Mingdong Shang

Sriram Srinivasan

Brian Scott Aust

Eileen C Brown

Diaa E Fathalla

Vikrant H Desai

Systems and methods are disclosed for clients and servers operating in a scaled cluster environment. Efficiencies are introduced to the process of connecting a client to a clustered environment by providing the client with the ability to attempt a connection with multiple servers in parallel. Servers operating the in the clustered environment are also capable of providing persistent storage of file handles and other state information. Ownership of the state information and persistent handles may be transferred between servers, thereby providing clients with the opportunity to move from one server to another while maintaining access to resources in the clustered environment.

SMB2 scaleout

A lease system is described herein that allows clients to request a lease to a remote file, wherein the lease permits access to the file across multiple applications using multiple handles without extra round trips to a server. When multiple applications on the same client (or multiple components of the same application) request access to the same file, the client specifies the same lease identifier to the server for each open request or may handle the request from the cache based on the existing lease. Because the server identifies the client's cache at the client level rather than the individual file request level, the client receives fewer break notifications and is able to cache remote files in more circumstances. Thus, by providing the ability to cache data in more circumstances common with modern applications, the lease system reduces bandwidth, improves server scalability, and provides faster access to data.

Access requests with cache intentions

Described are embodiments directed at providing a witness service that sends notifications with a resource state to clients. Embodiments provide a protocol that includes various messages for registering and receiving notifications regarding the state of a resource. The protocol may include a message for requesting node information from a first node in a cluster. The node information identifies nodes in the cluster that provide a witness service, which monitors a resource. The protocol includes a message that is used to register with the witness service for notifications regarding a state, or state change, of a network or cluster resource. The protocol also includes messages for sending notifications with state information of the resource.

Providing a witness service

Aspects of the subject matter described herein relate to client-side caching. In aspects, when a client receives a request for data that is located on a remote server, the client first checks a local cache to see if the data is stored in the local cache. If the data is not stored in the local cache, the client may check a peer cache to see if the data is stored in the peer cache. If the data is not stored in the peer cache, the client obtains the data from the remote server, caches it locally, and publishes to the peer cache that the client has a copy of the data.

Populating and using caches in client-side caching

Client-based caching of remote files

An application instance identifier is employed with various systems and methods in order to provide a requestor with continuous access to a resource when operating in a client clustered environment. A requestor residing on a first client may attempt to access a resource. The first client sends a request to access the resource. The request may be associated with an application instance identifier that identifies the requestor. At some point, the first client fails and the requestor is associated with a second client via a failover mechanism. The second client sends a second request to access the resource on behalf of the requestor. The second request is associated with the requestor's application instance identifier. The application instance identifier is used to identify the second request as belonging to the same requestor as the first request, thereby granting the second request to access the resource while avoiding a conflict situation.

Clustered client failover

Aspects of the subject matter described herein relate to synchronizing for directory actions performed while offline. In aspects, file system objects that reside on a remote data store are made available for offline use. While offline, a client receives an indication that a directory is to be deleted or renamed. In response, the client modifies its local copy of the directory and its descendants if any and stores one or more tombstones that include information that the client can use when synchronizing the changes made to the directory when the client is reconnected to the remote data store. When the client reconnects to the remote data store, the client synchronizes changes made while offline with the remote data store. Resolution conflict mechanisms may be used during this synchronization.

Synchronizing for directory changes performed while offline

A system and method for providing information control block (ICB) tracking streams for Universal Disk Format (UDF) file systems. The streams assist in tracking the location of the ICBs on the media, and promote clustering of ICBs. Both of these factors increase the speed of the UDF file system by greatly reducing the time to scan and locate files.

Growing community of inventors

Redmond, WA, United States of America

Thomas Ewan Jolly