Distributed-Lock

Implementing Distributed Locking with Redis and IDistributedLock Distributed locking is a critical feature for ensuring resource safety in distributed applications. Here’s how you can implement a distributed lock using the IDistributedLock interface and Redis as the backing store, leveraging the StackExchange.Redis library. Step 1: Implement the IDistributedLock Interface Let’s start by creating the RedisDistributedLock class to implement the IDistributedLock interface: using StackExchange.Redis; using System; using System.Threading.Tasks; public class RedisDistributedLock : IDistributedLock { private readonly IDatabase _database; private readonly string _lockKey; private string _lockToken; public RedisDistributedLock(IDatabase database, string lockKey) { _database = database; _lockKey = lockKey; _lockToken = Guid.NewGuid().ToString(); } public async Task<bool> AcquireLockAsync(string resource, TimeSpan leaseTime) { _lockToken = Guid.NewGuid().ToString(); return await _database.StringSetAsync(resource, _lockToken, leaseTime, When.NotExists); } public async Task RenewLockAsync(TimeSpan leaseTime) { if (!await _database.StringGetAsync(_lockKey).ConfigureAwait(false).Equals(_lockToken)) { throw new InvalidOperationException("Cannot renew a lock that is not held."); } await _database.KeyExpireAsync(_lockKey, leaseTime); } public async Task ReleaseLockAsync() { var token = await _database.StringGetAsync(_lockKey); if (token == _lockToken) { await _database.KeyDeleteAsync(_lockKey); } } public void Dispose() { ReleaseLockAsync().GetAwaiter().GetResult(); } } Step 2: Create a Sample Console Application Next, build a console application to demonstrate the functionality of the RedisDistributedLock: ...

RedisDistributedLock Implementation in Aspect-Oriented Programming (AOP) Aspect-Oriented Programming (AOP) lends itself well to distributed resource management tasks such as locking. Below is an implementation of a Redis-based distributed lock using the StackExchange.Redis library, focusing on resource isolation and concurrency control. RedisDistributedLock Class Here is the complete implementation: using StackExchange.Redis; using System; using System.Threading.Tasks; public class RedisDistributedLock : IDisposable { private readonly IDatabase _redisDb; private readonly string _lockKey; private readonly string _lockValue; private bool _acquired; public RedisDistributedLock(IDatabase redisDb, string resourceKey) { _redisDb = redisDb; _lockKey = $"lock:{resourceKey}"; _lockValue = Guid.NewGuid().ToString(); // random token } /// <summary> /// Attempts to acquire a lock for the specified lock key with a given expiry. /// </summary> /// <param name="expiry">Duration for lock expiry.</param> /// <returns>True if the lock was acquired; otherwise, false.</returns> public async Task<bool> AcquireAsync(TimeSpan expiry) { _acquired = await _redisDb.StringSetAsync( key: _lockKey, value: _lockValue, expiry: expiry, when: When.NotExists); return _acquired; } /// <summary> /// Releases the lock if it’s still held by this instance. /// </summary> public async Task ReleaseAsync() { if (_acquired) { // Verify token before deleting. var currentValue = await _redisDb.StringGetAsync(_lockKey); if (currentValue == _lockValue) { await _redisDb.KeyDeleteAsync(_lockKey); } _acquired = false; } } /// <summary> /// Cleanup method ensuring the lock is freed. /// </summary> public void Dispose() { ReleaseAsync().GetAwaiter().GetResult(); } } Acquiring and Releasing the Lock Using the RedisDistributedLock class to acquire and release locks ensures concurrency control in distributed systems. ...

Understanding Distributed Locks: Use Cases, Benefits, and Implementation Distributed locks play a vital role in ensuring safe and synchronized access to shared resources in distributed systems. Let’s explore when and why to use distributed locks, their benefits, and practical implementation examples. 1. Introduction to Distributed Locks A distributed lock ensures that only one process or service can access a shared resource at a time, even in a system with multiple nodes. For example, you can use distributed locks to: ...