DistributedLeaseManager.AzureCosmosDb

DistributedLeaseManager.AzureCosmosDb

Description

A simple C#/.NET distributed lease/lock manager (DLM) implementation.

Inspired by the https://github.com/fbeltrao/azfunctions-distributed-locking

This library contains a lease storage implemented using the Azure Cosmos DB.

Usage

1. (Optionally) Register your Azure Cosmos DB Client in the DI container

2. Register the Distributed Lease Manager in the DI container:

   builder.Services.AddCosmosDbDistributedLeaseManager("DatabaseName", "DistributedLeases");

   or specify the Cosmos DB connection string in case you skipped the first step:

   builder.Services.AddCosmosDbDistributedLeaseManager("ConnectionString", "DatabaseName", "DistributedLeases");

   or utilize one of the overloads that accepts an action in order to also customize the partition key path:

   builder.Services.AddCosmosDbDistributedLeaseManager(
       "AccountEndpoint=https://localhost:8081/;AccountKey=C2y6yDjf5/R+ob0N8A7Cgv30VRDJIWEHLM+4QDU5DE2nQ9nDuVTqobD4b8mGGyPMbIZnqyMsEcaGQy67XIw/Jw==",
       options =>
       {
           options.DatabaseName = "DatabaseName";
           options.ContainerName = "DistributedLeases";
           options.PartitionKeyPath = "/partitionKey";
       }); 

   Note: Partition Key Path must start with /. Nested partition key paths such as /my/partitionKey are not supported.

3. Inside your controller/service inject the IDistributedLeaseManager and call the TryAcquireLease method. Verify if the result was successful - if it was then you can proceed with the operation; otherwise, someone else has acquired the lease:

   await using var leaseResult = await leaseManager.TryAcquireLease(resourceId, TimeSpan.FromSeconds(5));
   
   if (!leaseResult.IsSuccessful)
   {
       // Someone else has required the lease for the resource.
       // You may want to either retry the acqusition or abort the operation.
   }
   else
   {
       // You are the lease owner now and can safely process the resource.
       // The lease will be released either when the leaseResult gets disposed
       // or when the lease expires (in the example above, in 5 seconds)
   }