Distributed Databases Questions Medium
A distributed lock in distributed databases refers to a mechanism used to coordinate and manage concurrent access to shared resources across multiple nodes or servers in a distributed database system. It ensures that only one transaction or process can access a particular resource at a time, preventing conflicts and maintaining data consistency.
In a distributed database environment, where data is spread across multiple nodes, it is crucial to ensure that concurrent transactions do not interfere with each other and maintain the integrity of the data. Distributed locks play a vital role in achieving this by providing a synchronization mechanism.
When a transaction or process needs to access a resource, it requests a lock on that resource. The distributed lock manager, which is responsible for managing locks across the distributed system, grants the lock if it is available. If the lock is already held by another transaction, the requesting transaction is put on hold until the lock is released.
Distributed locks can be of different types, such as shared locks and exclusive locks. A shared lock allows multiple transactions to read the resource simultaneously but prevents any transaction from modifying it. An exclusive lock, on the other hand, grants exclusive access to a single transaction, preventing any other transaction from reading or modifying the resource.
The distributed lock manager keeps track of the locks granted to transactions and ensures that they are released appropriately. It also handles deadlock detection and resolution, where multiple transactions are waiting for resources held by each other, leading to a deadlock situation.
Overall, distributed locks are essential in distributed databases to maintain data consistency, prevent conflicts, and ensure proper synchronization among concurrent transactions accessing shared resources.