Browse Definitions :
Definition

OpLock (opportunistic lock)

Opportunistic lock (OpLock) is a form of file locking used to facilitate caching and access control and improve performance.

OpLocks are made to enable simultaneous file access by multiple users while also improving performance for synchronized caches. In a synchronized cache, when a client requests a file from a server, the shared file may be cached to avoid subsequent trips over the network to retrieve it.

OpLock is part of the Server message block (SMB) protocol, also known as the Common Internet File System (CIFS) protocol.  OpLocks include batch locks, exclusive locks and level 2 OpLocks.

Batch locks are used where frequent open and close requests can be paired; the system ignores unnecessary close requests if the file is to be reopened, thus reducing the performance impact of the requests.

Exclusive locks are used when a client is the only entity or process that has the file open. In that case, all changes are cached before sending the file back to the server.

Level 2 OpLocks come into effect when an OpLock held by a client is opened by a third party, substituting the client’s former exclusive lock.

An OpLock is not a command but a request typically sent from client to server and fulfilled under allowable conditions or the particular opportunity for which it is named. When a lock is no longer valid a break is sent to the client to end it.

There are some implications that OpLocks can cause corruption and performance issues in ISAM  (Indexed Sequential Access Method) databases. As a result, some companies – Symantec among them -- have recommended disabling OpLocks as a best practice.

This was last updated in May 2015

Continue Reading About OpLock (opportunistic lock)

SearchCompliance
  • OPSEC (operations security)

    OPSEC (operations security) is a security and risk management process and strategy that classifies information, then determines ...

  • smart contract

    A smart contract is a decentralized application that executes business logic in response to events.

  • compliance risk

    Compliance risk is an organization's potential exposure to legal penalties, financial forfeiture and material loss, resulting ...

SearchSecurity
  • threat modeling

    Threat modeling is a procedure for optimizing application, system or business process security by identifying objectives and ...

  • social engineering

    Social engineering is an attack vector that relies heavily on human interaction and often involves manipulating people into ...

  • distributed denial-of-service (DDoS) attack

    A distributed denial-of-service (DDoS) attack is one in which multiple compromised computer systems attack a target, such as a ...

SearchHealthIT
SearchDisasterRecovery
  • change control

    Change control is a systematic approach to managing all changes made to a product or system.

  • disaster recovery (DR)

    Disaster recovery (DR) is an organization's ability to respond to and recover from an event that affects business operations.

  • risk mitigation

    Risk mitigation is a strategy to prepare for and lessen the effects of threats faced by a business.

SearchStorage
  • race condition

    A race condition is an undesirable situation that occurs when a device or system attempts to perform two or more operations at ...

  • storage security

    Storage security is the group of parameters and settings that make storage resources available to authorized users and trusted ...

  • cloud storage

    Cloud storage is a service model in which data is transmitted and stored on remote storage systems, where it is maintained, ...

Close