abp/docs/en/Distributed-Locking.md

Distributed Locking

Distributed locking is very useful to manage many processes that request the same object. In a normal case, accessing the same object from different applications can corrupt the value of resources. In terms of accuracy, we may need to protect the value that's why a lock will be necessary.

To use in ABP, you should download the below NuGet package or can open any command apps and run the below command.

abp add-package Volo.Abp.DistributedLocking

using Volo.Abp.DistributedLocking; 
namespace AbpDemo
{
    public class MyService : ITransientDependency
    {
        private readonly IAbpDistributedLock _distributedLock;
		public MyService(IAbpDistributedLock distributedLock)
        {
            _distributedLock = distributedLock;
        }
        
        public async Task MyMethodAsync()
        {
            await using (var handle = await _distributedLock.TryAcquireAsync("NameOfLock"))
            {
                if (handle != null)
                {
                    //your code
                }
            }   
        }
    }
}

This provider contains a method named TryAcquireAsync and this method returns null if the lock could not be handled. name is mandatory. It keeps the locked provider name. This name should be unique, otherwise it will be seen as a different lock. timeout is set as default. If it fells deadlock and doesn't work properly you can use define the time to kill it. cancellationToken is set as default. It enables cooperative cancellation between threads, thread pool work items, or Task objects

ABP depends on DistributedLock.Core library which provides a distributed locking system for concurrency control in a distributed environment. There are many distributed lock providers including Redis, SqlServer and ZooKeeper. You may use the one you want. ABP implements the Redis provider for you and you may customize the others yourselves.

Firstly, you should add DistributedLock.Redis NuGet package to your project, then add the following code into the ConfigureService method of your ABP module class.

using Medallion.Threading;
using Medallion.Threading.Redis;
namespace AbpDemo
{
	public class MyModule : AbpModule
	{
		public override void ConfigureServices(ServiceConfigurationContext context)
		{
			//the other configurations
			var configuration = context.Services.GetConfiguration();
			
			context.Services.AddSingleton<IDistributedLockProvider>(sp =>
			{
				var connection = ConnectionMultiplexer.Connect(configuration["Redis:Configuration"]);
				return new RedisDistributedSynchronizationProvider(connection.GetDatabase());
			});
		}
	}
}

Also, you should add your Redis configuration in appsetting.json. You may change the structure of the JSON file but it must match with the above configuration code.

"Redis": {
    "Configuration": "127.0.0.1"
}

As mentioned the above, this implemantition is for Redis and for more detail you can visit the official site.