Abstract: A cluster based file service may operate on a cluster of two or more independent devices that have access to a common data storage. The file service may have a namespace definition with each device in the cluster, but may be modified by any device operating the file service. Each instance of the file service may identify and capture a command that changes the namespace structure and cause the change to be propagated to the other members of cluster. If one of the devices in the cluster does not successfully perform an update to the namespace structure, that device may be brought offline. The cluster based file service may permit adding or removing devices from the cluster while the file service is operating, and may provide a high throughput and high availability file service.

Abstract: Aspects of the subject matter described herein relate to a distributed network name. In aspects, computers of a cluster have components of a distributed network name service. The network name service has a leader and clones that are hosted on the computers of the cluster. The leader is responsible for updating a name server with network names and addresses of the computers. The leader is also responsible for configuring a security server that allows clients to securely access the computers. The network name service provides credentials to local security authorities of the computers so that a client that attempts to access a service of the computers can be authenticated.

Abstract: The present invention extends to methods, systems, and computer program products for sharing volumes between clustered nodes. Embodiments of the invention include a Clustered Shared Volume File System (CsvFs) that appears to clients as a local file system. The CsvFs communicates to a node where a disk is mounted to coordinate access to files on the disks. CsvFs uses Opportunistic Locks (oplocks) to decide when direct access to a volume is safe. CsvFs can be extended with oplock upgrade mechanisms that allow a coordinating node to tell CsvFs when it is safe to attempt to upgrade oplock. CsvFs also uses a transitivity property of oplocks to be able to grant (delegate) oplocks to clients that are on top of CsvFs.

Abstract: Defining a storage topology of a distributed computing system including a set of machine nodes. A method includes dynamically receiving from a number of nodes in the distributed computing system information about storage devices. Each node sends information about storage devices connected to that particular node. The information is sent dynamically from each node as conditions related to storage change and as a result of conditions related to storage changing. From the received information, the method includes dynamically constructing a storage topology representation of the distributed computed system.

Abstract: Implementing point in time back-up. A method that may be practiced in a distributed computing environment. The distributed computing environment includes a number of computing system nodes. The method includes at a first node in the computing environment, taking a snapshot of a cluster volume. The cluster volume stores data items (e.g. files/blocks). Taking a snapshot includes marking a point in time for data items in the volume. The method further includes receiving a notification that a different node in the computing environment than the first node, has determined to change a data item in the cluster volume at a point after the marked point in time from an old version of the data item to a new version of the data item. The method further includes at the first node, saving the old version of the data item prior to modification.

Abstract: Coordinating methods of I/O access to a shared data store. A method includes at a node, in a distributed system, performing one or more I/O operations on the shared data store using direct I/O access on a virtual data container. Direct I/O access includes performing I/O operations directly from the node to the shared data store including not having an owner node perform the I/O operation on the shared data store on the node's behalf. The owner node is a different node than the node doing the direct I/O operation. The owner node accesses the shared data store through a local data container. The method further includes determining that one or more subsequent I/O operations should be performed using redirected I/O access, where I/O operations are directed through a centralized node. The method further includes indicating to nodes in the distributed system to switch to redirected I/O access method.

Abstract: Aspects of the subject matter described herein relate to client affinity in distributed load balancing systems. In aspects, a request from a requester is sent to each server of a cluster. Each server determines whether it has affinity to the requester. If so, the server responds to the request. Otherwise, if the request would normally be load balanced to the server, the server queries the other servers in the cluster to determine whether any of them have affinity to the requester. If one of them does, the server drops the request and allows the other server to respond to the request; otherwise, the server responds to the request.

Abstract: Described is a technology in a network load balancing system (node cluster), by which client affinity is preserved across cluster configuration changes, including for new connections from a previous client. Each node maintains a list of the clients that are to remain (have affinity, or “stickiness”) with that node, including following bucket redistribution resulting from convergence. Each affinity list is communicated during convergence so that other nodes may build an exception list or lists. Via a node's exception list, the node that owns a bucket corresponding to a client knows of the affinity with another node and thus drops any packets from that client. Affinity may expire, whereby the node having affinity with that client releases it and notifies the node owning the bucket for that client that the client is no longer to be treated as an exception.

Abstract: Described is a technology by which a storage volume is shared by cluster nodes of a server cluster. In one implementation, each node includes a redirector that provides shared access to the volume from that node. The redirector routes file system metadata requests from applications and the like through a first (e.g., SMB) communications path to the owning node, and routes file system read and write data to the storage device through a second, high-speed communications path such as direct direct block level I/O. An owning node maintains ownership of the storage device through a persistent reservation mechanism that writes a key to a registration table associated with the storage device. Non-owning nodes write a shared key. The owning node validates the shared keys against cluster membership data, and preempts (e.g., removes) any key deemed not valid. Security mechanisms for controlling access are also described.

Abstract: Described is a technology in a network load balancing system (node cluster), by which client affinity is preserved across cluster configuration changes, including for new connections from a previous client. Each node maintains a list of the clients that are to remain (have affinity, or “stickiness”) with that node, including following bucket redistribution resulting from convergence. Each affinity list is communicated during convergence so that other nodes may build an exception list or lists. Via a node's exception list, the node that owns a bucket corresponding to a client knows of the affinity with another node and thus drops any packets from that client. Affinity may expire, whereby the node having affinity with that client releases it and notifies the node owning the bucket for that client that the client is no longer to be treated as an exception.

Abstract: Described is a technology by which a storage volume is shared by cluster nodes of a server cluster. In one implementation, each node includes a redirector that provides shared access to the volume from that node. The redirector routes file system metadata requests from applications and the like through a first (e.g., SMB) communications path to the owning node, and routes file system read and write data to the storage device through a second, high-speed communications path such as direct direct block level I/O. An owning node maintains ownership of the storage device through a persistent reservation mechanism that writes a key to a registration table associated with the storage device. Non-owning nodes write a shared key. The owning node validates the shared keys against cluster membership data, and preempts (e.g., removes) any key deemed not valid. Security mechanisms for controlling access are also described.

Abstract: Aspects of the subject matter described herein relate to client affinity in distributed load balancing systems. In aspects, a request from a requester is sent to each server of a cluster. Each server determines whether it has affinity to the requester. If so, the server responds to the request. Otherwise, if the request would normally be load balanced to the server, the server queries the other servers in the cluster to determine whether any of them have affinity to the requester. If one of them does, the server drops the request and allows the other server to respond to the request; otherwise, the server responds to the request.

Abstract: A method for writing compressed audio data to a compact disc media is provided. The method includes selecting songs to be written in a session and reserving a first track. After the first is reserved, the method proceeds to writing a first temporary data structure and audio data to a second track following the first track. After the second track is closed, part of first temporary data structure (e.g., the recompiled INFO.CD3 part) is written to the reserved first track and the session is closed. Another method includes beginning a session writing the compressed audio data to the compact disc media. A track that includes a file system and an audio data section is then written. The writing of the track further includes writing an INFO.CD3 file, writing an ISO file system, and writing a FILEINFO.LC file following the ISO file system. Once the audio data section is written, the method proceeds to closing the track and closing the session.

Abstract: A method for writing compressed audio data to a compact disc media is provided. The method includes selecting songs to be written in a session and reserving a first track. After the first is reserved, the method proceeds to writing a first temporary data structure and audio data to a second track following the first track. After the second track is closed, part of first temporary data structure (e.g., the recompiled INFO.CD3 part) is written to the reserved first track and the session is closed. Another method includes beginning a session writing the compressed audio data to the compact disc media. A track that includes a file system and an audio data section is then written. The writing of the track further includes writing an INFO.CD3 file, writing an ISO file system, and writing a FILEINFO.LC file following the ISO file system. Once the audio data section is written, the method proceeds to closing the track and closing the session.

Abstract: An improved file system and method for incrementally recording data on compact discs is disclosed. The improved file system and method employs compact discs physically formatted in accordance with the so-called Orange Book specification. Files to be stored are selected from time to time and are divided into packets. The packets are then recorded in a program area of the compact disc together with link, run-in and run-out blocks in a format compatible with the Orange Book rules for linking incrementally recorded packets. File linking information is also stored with each file. If desired, files may, but need not, be recorded in a form compatible with existing CD-ROM and drivers adhering to the ISO-9660 standard. As selected files are recorded, file and directory information are stored in a first storage area either in a host system or in a track of the compact disc in a double linked and highly efficient format.

Abstract: An improved file system and method for incrementally recording data on compact discs is disclosed. The improved file system and method employs compact discs physically formatted in accordance with the so-called Orange Book specification. Files to be stored are selected from time to time and are divided into packets. The packets are then recorded in a program area of the compact disc together with link, run-in and run-out blocks in a format compatible with the Orange Book rules for linking incrementally recorded packets. File linking information is also stored with each file. If desired, files may, but need not, be recorded in a form compatible with existing CD-ROM and drivers adhering to the ISO-9660 standard. As selected files are recorded, file and directory information are stored in a first storage area either in a host system or in a track of the compact disc in a double linked and highly efficient format.

Abstract: Disclosed is a system for minimizing the utilization of an I/O bus by a first data-writing peripheral device that is connected to the I/O bus. The system has a second peripheral device that shares the I/O bus connection. The system includes the operations of transferring data to a drive buffer that is in the first data-writing peripheral device. The transferring being configured to continue until the drive buffer has reached a full state. Performing a pre-write calibration of the first data-writing peripheral device after the drive buffer has reached the full state. Commencing a writing of a portion of the data contained in the drive buffer, such that the first data received by the drive buffer is written first. The system further including releasing the I/O bus connection by placing a write thread of the first data-writing peripheral device in a sleep mode.