102 results about "Lock manager" patented technology

Techniques for concurrent access to a resource object, such as a database, include generating a lock data structure for a particular resource object. The lock data structure includes data values for a resource object identification, a lock type, and a version number. The version number is related to a number of changes to the resource object since the lock data structure was generated. A request is received from a requesting process. The request is for a requested lock type for access to the particular resource object. It is determined whether to grant the request based on the requested lock type and the lock type in the lock data structure. By carrying a lock version number in a lock data structure managed by a lock manager, improved optimistic locking is provided in a database. In particular, the approach enables introduction of optimistic locking to a legacy database without requiring burdensome changes to a database table schema.

A method of controlling concurrent users of a distributed resource on a network is disclosed. In one aspect, there are one or more local lock managers executing on corresponding hosts and cooperating as a distributed lock manager. The resource is limited to a maximum number of concurrent users. A user identification for each user is associated with one host. In response to a request associated with a particular user associated with a first host, a lock is requested from a first local lock manager process executing on the first host. A related method of handling a request for a count-limited resource includes receiving a request from a client process for the computer resource. If it is determined that the request exceeds a maximum count for the resource, then it is determined whether a current time is within a retry time period of the client's first request. If it is determined the current time is within the retry time period, then it is automatically determined again whether the request exceeds the maximum count for the resource. If it is determined that the request does not exceed the maximum count, then the resource is provided to the client process.

A method, system and program code for implementing distributed locks to be maintained through the use of on disk heartbeats. An instance of a node need only maintain a single heartbeat for all locks associated with the node and all of its processes. The node updates its heartbeat by accessing common storage, either virtual or physical, and updating a timestamp value in its heartbeat within a predetermined time interval, otherwise the heartbeat becomes stale. Expired heartbeats can be cleared or broken to allow redistribution of any locks associated therewith. The inventive technique may be implemented in a traditional computer environment or in a fully or partially virtualized environment and requires no use of an IP network or a separate network based lock manager.

A method and a distributed locking system for the management of lock resources in a distributed files system having several lock managers, each managing lock resources in its respective domain. Each lock manager maintains a registry lock file that comprises of a list of all locked files and a list of lock requests. The registry lock files of all lock managers in the distributed locking system are saved in a central database. Furthermore, the system enables concurrent locking operations of different file sharing protocols on the same file system resources.

A multi-protocol lock manager efficiently manages granting, revoking and releasing of various types of locks on files or regions of files located on a file server, such as a filer. The various locks are associated with multiple different file access protocols, each having its own semantics. The multi-protocol lock manager allows the filer to take appropriate actions with respect to locking requests and other file access operations, while ensuring that the actions taken are always consistent with semantic requirements for each lock, as established by the associated file access protocol.

A method may involve: a node included in a cluster looking up a file in a metadata name cache; in response to a miss for the file in the metadata name cache, the node creating a metadata name cache entry for the file in the metadata name cache, where the metadata name cache entry includes a copy of a cookie associated with metadata allocated to the file; in response to a lock on the metadata changing state for the node, the node modifying the cookie associated with the metadata, where the lock changes state for the node in response to a request to a global lock manager for the lock on the metadata; and comparing the copy of the cookie stored in the metadata name cache entry to a current value of the cookie associated with the metadata to determine if the metadata name cache entry is valid.

Disclosed is a method, system, and program for transaction management. An indication is received that a transaction is beginning. An operation identifier for the transaction is generated. Actions are logged for the transaction identified by the operation identifier, wherein the actions include requests, corresponding reverse requests, and locks granted.

Also disclosed is a method, system, and program for locking management. A command is received that specifies an operation identifier. It is determined whether the command is associated with a transaction using the operation identifier. If it is determined that the command is associated with a transaction, operating at a transaction level of locking.

Further disclosed is a method, system, and program for lock management. Under control of a lock manager, (i) lock request queuing is performed, (ii) heartbeat functions are performed, and (iii) state information is maintained.

A transaction manager may be paused so that transactions managed by the transaction manager are prevented from making transactional state changes. When all transactions being coordinated by a transaction manager are paused, the transaction manager may be said to be paused or frozen. While the transaction manager is paused, the transactions that the transaction manager is supporting may not be allowed to complete. A transaction manager may be configured to obtain permission from a transaction freeze manager in order to transition the state of a transaction. The transaction freeze manager may function as a read/write lock manager controlling locks on a transaction freeze object. In servicing a transaction state transition request, the transaction freeze manager may grant the transaction manager a read lock on the transaction freeze object. In servicing a transaction manager pause request, the transaction freeze manager may grant an administrative entity a write lock on the transaction freeze object.

A method and system are disclosed for migrating network resources to improve network utilization, for use in a multi-node network wherein nodes of the network share network resources. The method comprises the steps of identifying a group of nodes that share one of the network resources, and identifying one of the nodes satisfying a specified condition based on at least one defined access latency metric. The shared resource is moved to the identified one of the nodes to reduce overall access latency to access the shared resource by said group of nodes. One embodiment of the invention provides a method and system to synchronize tasks in a distributed computation using network attached devices (NADs). A second embodiment of the invention provides a method and system to reduce lock latency and network traffic by migrating lock managers to coupling facility locations closest to nodes seeking resource access.

In a shared data system comprising one or more primary nodes and a plurality of secondary nodes, global lock manager on a primary node manages locks for shared resources by exchanging an abstract lock state with local lock managers on the secondary nodes. The abstract lock state includes a particular representation of all of the applications on the nodes that are requesting or are granted locks. The exchange of these particular lock states instead of individual requests improves performance by increasing concurrency and reducing off-machine communication. A global deadlock detector on a node detects and resolves global deadlocks, in conjunction with local deadlock detectors on the secondary nodes.

Distributed transaction and lock management techniques are disclosed that manage and regulate access to distributed data. A lock manager module is provided for regulating access to resources by applications in a system having a number of nodes each communicatively coupled to a network. The module can be configured to be fault tolerant. In one embodiment, the module uses a totally ordered transport that imposes total ordering protocols on messaging between nodes. The module can exploit the multicast ability of the network (e.g., Ethernet or other network features that enable multicast). The module includes a queue for each resource, the queue identifying the node that owns distributed lock for that resource. Each queue can be replicated across the nodes in a distributed configuration.

The invention provides a dynamic password lock system capable of changing a password with date (or time), which comprises a lock body and a temporary password generator. A fixed password of the password lock is stored in a non-volatile memory in the lock body; a temporary password for unlocking is calculated by a specific algorithm (such as one-way hash function and the like) according to the fixed password and the date; and with the alteration of the fixed password or the change of date, the temporary password correspondingly and automatically changes in a calculable way. Therefore, the temporary password can be calculated by a password lock manager knowing the fixed password in the password lock without touching the password lock; and after the password lock is used by a temporary user, the temporary user can unlock the password lock with the temporary password in a specific time period.

A transaction manager may be paused so that the transactions it manages are prevented from making transaction state changes. While the transaction manager is paused, the transactions that the transaction manager is executing may not be allowed to complete. A transaction manager may be configured to obtain permission from a transaction freeze manager in order to transition the state of a transaction. The transaction freeze manager may function as a read/write lock manager controlling locks on a transaction freeze object. In servicing a transaction state transition request, the transaction freeze manager may grant the transaction manager a read lock on the transaction freeze object. In servicing a transaction manager pause request, the transaction freeze manager may grant an administrative entity a write lock on the transaction freeze object.

The invention provides a dynamic password electronic lock system in which a password changes according to random codes. The system is composed of a lock body and a temporary password generator. A fixed password of a password lock is stored in a nonvolatile storage of the lock body, when a temporary user uses the electronic lock, the electronic lock generates the random codes R, a temporary password used for unlocking is obtained through calculation of the fixed password and the random codes according to a special algorithm (such as a one-way hash function), and automatic calculable changing is performed on the temporary password along with changes of the fixed password or differences of the random codes generates each time. Thus, the temporary password can be obtained through calculation when a password lock manager mastering the fixed password in the password lock receives the random codes, and after the system is delivered to the temporary password lock user, the temporary password lock user can perform unlocking through the temporary password in an effective period of time.

A method and system for asserting a lock in a distributed file system is provided. All distributed locks have a lease for a limited time period, wherein the lease may be renewed periodically. A lock manager data structure is provided to maintain mode compatibility of locks granted to different client nodes for the same object. The process of acquiring or reasserting a lock includes determining whether there are other valid locks in use, as well as whether a valid lock is in operation in a conflicting or compatible mode with a requested lock. A new lock lease may be granted and a lock lease which has expired may be reasserted if a conflicting lease is not present.

It's an object-based storage system to model attributes of distributed locks, a distributed storage system for storage of multi-client visit to the sharing of resources, aimed at enhancing the efficiency of Reading lock visit. The present invention include data locking and metadata management for the management of locks, running on the object-based storage system, data management lock-operation in various storage devices on the target, including data objects name space module, access patterns attribute value module installed, local Queue processing module and functional processing module; Each data lock manager responsible for data management object locking, metadata management lock-operation in various metadata servers, including metadata objects name space module, local Queue processing module and functional processing modules, each metadata management lock-lock for metadata management. The invention uses the object storage technology by expanding access pattern attribute value and improves the efficiency of Reading lock visit.

A generic lock manager service is provided which allows locks and lock requests to be recovered across system failures and restarts. When a lock request that includes a request to isolate a particular data object is received, the lock manager service examines a lock request queue to determine if the queue contains a second lock request for the data object specified in the lock request. If no second lock request is present, a sequence identifier is assigned to the lock request indicating a lock request processing order for the data object specified in the lock request, and the lock request is persisted in a persistent storage. If a second lock request is present, a maximum sequence identifier of all lock requests directed to the data object is identified. The next higher sequence identifier is assigned to the lock request and the lock request is also persisted in a persistent storage.

The invention provides a dynamic coded lock system for acquiring codes by virtue of table look-up. The dynamic coded lock system comprises a lock body and a temporary code generator, wherein a fixed code and a key-value data table of a coded lock are stored in a nonvolatile memory in the lock body; when an electronic lock is used by a temporary user, a key code R is displayed by the electronic lock, a temporary code for unlocking the lock is obtained by finding a corresponding value code X in the data table by virtue of the key code R, besides, the fixed code can be used as a parameter to convert the value code X into the temporary code for use, and the temporary code is calculably changed along the changing of the fixed code or the difference of key codes displayed in each time. Therefore, the temporary code can be calculated by a coded lock manager knowing the fixed code and the data table in the coded lock when the key code is received, and after the temporary code is passed to the temporary coded lock user, the lock can be locked by the temporary coded lock user by virtue of the temporary code in a valid time period.

Messages between trading partners can be processed persistently using a persistence framework, which can include a transaction manager, a locking manager, and a logging mechanism. A transaction manager can initiate a transaction for a request, and can enlist and modify any object or resource useful in processing the request. A locking manager can lock any of these objects, using inflated and/or individual locks, to prevent other resources or transactions from accessing the object during the transaction. A logging component can track any modifications of the object, while a transaction manager can manage state for the object. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures, and the claims.

A compute cluster including multiple compute nodes may implement distributed lock management using conditional updates to a distributed key value data store. It may be determined, at one or more compute nodes of a compute cluster, that particular lock is available based on a respective lock entry for the particular lock maintained in a lock manager table at a key value data store. The key value data store may be configured to perform conditional write requests for updates to data store at the key value, and may maintain data according to a distributed durability scheme. Compute nodes that determine that a lock is available may send a conditional write request to the key value data store in order to acquire the particular lock. The compute node that acquired the particular lock may be identified based on the successfully completed conditional write request to the respective lock entry.

A method for handling service requests in a data processing system is disclosed. In response to a service request, a priority of the service request is determined by mapping a context of the service request to a service level agreement (SLA). SLA-aware and timeout-conscious and preemptive and replayable lock manager is designed to account for different operational goals and different importance to satisfy various SLAs. An average processing time of the service request is then calculated based on statistical results. The service request will be allowed to process if the determined average processing time meets historical guarantee situations.