├── DynamoLock
    ├── ILockTableProvisioner.cs
    ├── ILocalLockTracker.cs
    ├── IHeartbeatDispatcher.cs
    ├── IDistributedLockManager.cs
    ├── DynamoLock.csproj
    ├── ServiceCollectionExtensions.cs
    ├── LocalLockTracker.cs
    ├── LockTableProvisioner.cs
    ├── HeartbeatDispatcher.cs
    └── DynamoDbLockManager.cs
├── Docker.Testify
    ├── PortsInUseException.cs
    ├── Docker.Testify.csproj
    └── DockerSetup.cs
├── DynamoLock.Tests
    ├── DynamoLock.Tests.csproj
    ├── DynamoDbDockerSetup.cs
    └── DynamoDbLockerManagerTests.cs
├── LICENSE.md
├── DynamoLock.sln
├── README.md
└── .gitignore


/DynamoLock/ILockTableProvisioner.cs:
--------------------------------------------------------------------------------
1 | using System.Threading.Tasks;
2 | 
3 | namespace DynamoLock
4 | {
5 |     public interface ILockTableProvisioner
6 |     {
7 |         Task Provision();
8 |     }
9 | }


--------------------------------------------------------------------------------
/DynamoLock/ILocalLockTracker.cs:
--------------------------------------------------------------------------------
 1 | using System.Collections.Generic;
 2 | 
 3 | namespace DynamoLock
 4 | {
 5 |     public interface ILocalLockTracker
 6 |     {
 7 |         void Add(string id);
 8 |         void Remove(string id);
 9 |         void Clear();
10 |         ICollection<string> GetSnapshot();
11 |     }
12 | }


--------------------------------------------------------------------------------
/DynamoLock/IHeartbeatDispatcher.cs:
--------------------------------------------------------------------------------
 1 | using System;
 2 | using System.Collections.Generic;
 3 | using System.Text;
 4 | using System.Threading;
 5 | 
 6 | namespace DynamoLock
 7 | {
 8 |     public interface IHeartbeatDispatcher
 9 |     {
10 |         void Start(string nodeId, TimeSpan heartbeat, long leaseTime);
11 |         void Stop();
12 |     }
13 | }
14 | 


--------------------------------------------------------------------------------
/Docker.Testify/PortsInUseException.cs:
--------------------------------------------------------------------------------
 1 | using System;
 2 | using System.Collections.Generic;
 3 | using System.Text;
 4 | 
 5 | namespace Docker.Testify
 6 | {
 7 |     public class PortsInUseException : Exception
 8 |     {
 9 |         public PortsInUseException() 
10 |             : base("Ports in range are not available")
11 |         {
12 |         }
13 |     }
14 | }
15 | 


--------------------------------------------------------------------------------
/DynamoLock/IDistributedLockManager.cs:
--------------------------------------------------------------------------------
 1 | using System;
 2 | using System.Threading;
 3 | using System.Threading.Tasks;
 4 | 
 5 | namespace DynamoLock
 6 | {
 7 |     public interface IDistributedLockManager
 8 |     {
 9 |         Task<bool> AcquireLock(string Id);
10 | 
11 |         Task ReleaseLock(string Id);
12 | 
13 |         Task Start();
14 | 
15 |         Task Stop();
16 |     }
17 | 
18 | }
19 | 


--------------------------------------------------------------------------------
/Docker.Testify/Docker.Testify.csproj:
--------------------------------------------------------------------------------
 1 | <Project Sdk="Microsoft.NET.Sdk">
 2 | 
 3 |   <PropertyGroup>
 4 |     <TargetFramework>netstandard2.0</TargetFramework>
 5 |   </PropertyGroup>
 6 | 
 7 |   <ItemGroup>
 8 |     <PackageReference Include="Docker.DotNet" Version="3.125.2" />
 9 |     <PackageReference Include="System.Diagnostics.Process" Version="4.3.0" />
10 |     <PackageReference Include="System.Net.NetworkInformation" Version="4.3.0" />
11 |     <PackageReference Include="System.Threading.Thread" Version="4.3.0" />
12 |   </ItemGroup>
13 | </Project>
14 | 


--------------------------------------------------------------------------------
/DynamoLock.Tests/DynamoLock.Tests.csproj:
--------------------------------------------------------------------------------
 1 | <Project Sdk="Microsoft.NET.Sdk">
 2 | 
 3 |   <PropertyGroup>
 4 |     <TargetFramework>netcoreapp2.1</TargetFramework>
 5 | 
 6 |     <IsPackable>false</IsPackable>
 7 |   </PropertyGroup>
 8 | 
 9 |   <ItemGroup>
10 |     <PackageReference Include="AWSSDK.DynamoDBv2" Version="3.3.16.3" />
11 |     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.9.0" />
12 |     <PackageReference Include="xunit" Version="2.4.0" />
13 |     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.0" />
14 |   </ItemGroup>
15 | 
16 |   <ItemGroup>
17 |     <ProjectReference Include="..\Docker.Testify\Docker.Testify.csproj" />
18 |     <ProjectReference Include="..\DynamoLock\DynamoLock.csproj" />
19 |   </ItemGroup>
20 | 
21 | </Project>
22 | 


--------------------------------------------------------------------------------
/LICENSE.md:
--------------------------------------------------------------------------------
 1 | MIT License
 2 | 
 3 | Copyright (c) 2019 Daniel Gerlag
 4 | 
 5 | Permission is hereby granted, free of charge, to any person obtaining a copy
 6 | of this software and associated documentation files (the "Software"), to deal
 7 | in the Software without restriction, including without limitation the rights
 8 | to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 9 | copies of the Software, and to permit persons to whom the Software is
10 | furnished to do so, subject to the following conditions:
11 | 
12 | The above copyright notice and this permission notice shall be included in all
13 | copies or substantial portions of the Software.
14 | 
15 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21 | SOFTWARE.
22 | 


--------------------------------------------------------------------------------
/DynamoLock/DynamoLock.csproj:
--------------------------------------------------------------------------------
 1 | <Project Sdk="Microsoft.NET.Sdk">
 2 | 
 3 |   <PropertyGroup>
 4 |     <TargetFramework>netstandard2.0</TargetFramework>
 5 |     <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
 6 |     <PackageProjectUrl>https://github.com/danielgerlag/DynamoLock</PackageProjectUrl>
 7 |     <PackageLicenseUrl>https://github.com/danielgerlag/DynamoLock/blob/master/LICENSE.md</PackageLicenseUrl>
 8 |     <Authors>Daniel Gerlag</Authors>
 9 |     <Company />
10 |     <RepositoryUrl>https://github.com/danielgerlag/DynamoLock.git</RepositoryUrl>
11 |     <RepositoryType>git</RepositoryType>
12 |     <PackageTags>Distributed lock manager</PackageTags>
13 |     <Description>DynamoLock is a client library for .Net Standard that implements a distributed lock manager on top of Amazon DynamoDB.</Description>
14 |     <Version>1.0.2</Version>
15 |     <AssemblyVersion>1.0.2.0</AssemblyVersion>
16 |   </PropertyGroup>
17 | 
18 |   <ItemGroup>
19 |     <PackageReference Include="AWSSDK.DynamoDBv2" Version="3.3.16.3" />
20 |     <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="2.2.0" />
21 |     <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="2.2.0" />
22 |   </ItemGroup>
23 | 
24 | </Project>
25 | 


--------------------------------------------------------------------------------
/DynamoLock/ServiceCollectionExtensions.cs:
--------------------------------------------------------------------------------
 1 | using System;
 2 | using System.Collections.Generic;
 3 | using System.Text;
 4 | using Amazon.DynamoDBv2;
 5 | using Amazon.Runtime;
 6 | using Microsoft.Extensions.DependencyInjection;
 7 | using Microsoft.Extensions.Logging;
 8 | using Microsoft.Extensions.Logging.Abstractions;
 9 | 
10 | namespace DynamoLock
11 | {
12 |     public static class ServiceCollectionExtensions
13 |     {
14 |         public static void AddDynamoLockManager(this IServiceCollection serviceCollection, AWSCredentials credentials, AmazonDynamoDBConfig config, string tableName)
15 |         {
16 |             serviceCollection.AddSingleton<ILocalLockTracker, LocalLockTracker>();
17 |             serviceCollection.AddSingleton<IHeartbeatDispatcher>(sp => new HeartbeatDispatcher(credentials, config, sp.GetService<ILocalLockTracker>(), tableName, sp.GetService<ILoggerFactory>() ?? new NullLoggerFactory()));
18 |             serviceCollection.AddSingleton<ILockTableProvisioner>(sp => new LockTableProvisioner(credentials, config, tableName, sp.GetService<ILoggerFactory>() ?? new NullLoggerFactory()));
19 |             serviceCollection.AddSingleton<IDistributedLockManager>(sp => new DynamoDbLockManager(credentials, config, tableName, sp.GetService<ILockTableProvisioner>(), sp.GetService<IHeartbeatDispatcher>(), sp.GetService<ILocalLockTracker>(), sp.GetService<ILoggerFactory>() ?? new NullLoggerFactory()));
20 |         }
21 |     }
22 | }
23 | 


--------------------------------------------------------------------------------
/DynamoLock.Tests/DynamoDbDockerSetup.cs:
--------------------------------------------------------------------------------
 1 | using System;
 2 | using System.Collections.Generic;
 3 | using System.Net;
 4 | using System.Text;
 5 | using Amazon.DynamoDBv2;
 6 | using Amazon.Runtime;
 7 | using Docker.Testify;
 8 | using Xunit;
 9 | 
10 | namespace DynamoLock.Tests
11 | {
12 |     public class DynamoDbDockerSetup : DockerSetup
13 |     {
14 |         public static string ConnectionString { get; set; }
15 | 
16 |         public static AWSCredentials Credentials => new EnvironmentVariablesAWSCredentials();
17 | 
18 |         public override string ImageName => @"amazon/dynamodb-local";
19 |         public override int InternalPort => 8000;
20 | 
21 |         public override void PublishConnectionInfo()
22 |         {
23 |             ConnectionString = $"http://localhost:{ExternalPort}";
24 |         }
25 | 
26 |         public override bool TestReady()
27 |         {
28 |             try
29 |             {
30 |                 AmazonDynamoDBConfig clientConfig = new AmazonDynamoDBConfig
31 |                 {
32 |                     ServiceURL = $"http://localhost:{ExternalPort}"
33 |                 };
34 |                 AmazonDynamoDBClient client = new AmazonDynamoDBClient(clientConfig);
35 |                 var resp = client.ListTablesAsync().Result;
36 | 
37 |                 return resp.HttpStatusCode == HttpStatusCode.OK;
38 |             }
39 |             catch
40 |             {
41 |                 return false;
42 |             }
43 | 
44 |         }
45 |     }
46 | 
47 |     [CollectionDefinition("DynamoDb collection")]
48 |     public class DynamoDbCollection : ICollectionFixture<DynamoDbDockerSetup>
49 |     {
50 |     }
51 | }
52 | 


--------------------------------------------------------------------------------
/DynamoLock/LocalLockTracker.cs:
--------------------------------------------------------------------------------
 1 | using System;
 2 | using System.Collections.Generic;
 3 | using System.Text;
 4 | using System.Threading;
 5 | 
 6 | namespace DynamoLock
 7 | {
 8 |     public class LocalLockTracker : ILocalLockTracker
 9 |     {
10 |         private readonly List<string> _localLocks = new List<string>();
11 |         private readonly AutoResetEvent _mutex = new AutoResetEvent(true);
12 | 
13 |         public void Add(string id)
14 |         {
15 |             _mutex.WaitOne();
16 | 
17 |             try
18 |             {
19 |                 _localLocks.Add(id);
20 |             }
21 |             finally
22 |             {
23 |                 _mutex.Set();
24 |             }
25 |         }
26 | 
27 |         public void Remove(string id)
28 |         {
29 |             _mutex.WaitOne();
30 | 
31 |             try
32 |             {
33 |                 _localLocks.Remove(id);
34 |             }
35 |             finally
36 |             {
37 |                 _mutex.Set();
38 |             }
39 |         }
40 | 
41 |         public void Clear()
42 |         {
43 |             _mutex.WaitOne();
44 |             try
45 |             {
46 |                 _localLocks.Clear();
47 |             }
48 |             finally
49 |             {
50 |                 _mutex.Set();
51 |             }
52 |         }
53 | 
54 |         public ICollection<string> GetSnapshot()
55 |         {
56 |             _mutex.WaitOne();
57 |             try
58 |             {
59 |                 return _localLocks.ToArray();
60 |             }
61 |             finally
62 |             {
63 |                 _mutex.Set();
64 |             }
65 |         }
66 |     }
67 | }
68 | 


--------------------------------------------------------------------------------
/DynamoLock.sln:
--------------------------------------------------------------------------------
 1 | 
 2 | Microsoft Visual Studio Solution File, Format Version 12.00
 3 | # Visual Studio 15
 4 | VisualStudioVersion = 15.0.28307.168
 5 | MinimumVisualStudioVersion = 10.0.40219.1
 6 | Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "DynamoLock", "DynamoLock\DynamoLock.csproj", "{C20C6C20-35A2-45A8-9FD7-64A409ED87EC}"
 7 | EndProject
 8 | Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Docker.Testify", "Docker.Testify\Docker.Testify.csproj", "{BE66FA2C-8624-415F-88DC-DC05ADF081B0}"
 9 | EndProject
10 | Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "DynamoLock.Tests", "DynamoLock.Tests\DynamoLock.Tests.csproj", "{84FA283C-0139-4475-914B-BEF52E5047E1}"
11 | EndProject
12 | Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution Items", "{5B57EFAA-0344-4DFC-91F7-6ACC38154C27}"
13 | 	ProjectSection(SolutionItems) = preProject
14 | 		LICENSE.md = LICENSE.md
15 | 		README.md = README.md
16 | 	EndProjectSection
17 | EndProject
18 | Global
19 | 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
20 | 		Debug|Any CPU = Debug|Any CPU
21 | 		Release|Any CPU = Release|Any CPU
22 | 	EndGlobalSection
23 | 	GlobalSection(ProjectConfigurationPlatforms) = postSolution
24 | 		{C20C6C20-35A2-45A8-9FD7-64A409ED87EC}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
25 | 		{C20C6C20-35A2-45A8-9FD7-64A409ED87EC}.Debug|Any CPU.Build.0 = Debug|Any CPU
26 | 		{C20C6C20-35A2-45A8-9FD7-64A409ED87EC}.Release|Any CPU.ActiveCfg = Release|Any CPU
27 | 		{C20C6C20-35A2-45A8-9FD7-64A409ED87EC}.Release|Any CPU.Build.0 = Release|Any CPU
28 | 		{BE66FA2C-8624-415F-88DC-DC05ADF081B0}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
29 | 		{BE66FA2C-8624-415F-88DC-DC05ADF081B0}.Debug|Any CPU.Build.0 = Debug|Any CPU
30 | 		{BE66FA2C-8624-415F-88DC-DC05ADF081B0}.Release|Any CPU.ActiveCfg = Release|Any CPU
31 | 		{BE66FA2C-8624-415F-88DC-DC05ADF081B0}.Release|Any CPU.Build.0 = Release|Any CPU
32 | 		{84FA283C-0139-4475-914B-BEF52E5047E1}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
33 | 		{84FA283C-0139-4475-914B-BEF52E5047E1}.Debug|Any CPU.Build.0 = Debug|Any CPU
34 | 		{84FA283C-0139-4475-914B-BEF52E5047E1}.Release|Any CPU.ActiveCfg = Release|Any CPU
35 | 		{84FA283C-0139-4475-914B-BEF52E5047E1}.Release|Any CPU.Build.0 = Release|Any CPU
36 | 	EndGlobalSection
37 | 	GlobalSection(SolutionProperties) = preSolution
38 | 		HideSolutionNode = FALSE
39 | 	EndGlobalSection
40 | 	GlobalSection(ExtensibilityGlobals) = postSolution
41 | 		SolutionGuid = {24170E17-383B-41D1-8CEA-1A2A4B8CFC21}
42 | 	EndGlobalSection
43 | EndGlobal
44 | 


--------------------------------------------------------------------------------
/DynamoLock.Tests/DynamoDbLockerManagerTests.cs:
--------------------------------------------------------------------------------
 1 | using System;
 2 | using System.Threading;
 3 | using System.Threading.Tasks;
 4 | using Amazon.DynamoDBv2;
 5 | using Microsoft.Extensions.Logging.Abstractions;
 6 | using Xunit;
 7 | 
 8 | namespace DynamoLock.Tests
 9 | {
10 |     [Collection("DynamoDb collection")]
11 |     public class DynamoDbLockerManagerTests
12 |     {
13 |         DynamoDbDockerSetup _dockerSetup;
14 |         private IDistributedLockManager _subject;
15 |         private TimeSpan _heartbeat = TimeSpan.FromSeconds(2);
16 |         private long _leaseTime = 3;
17 | 
18 |         public DynamoDbLockerManagerTests(DynamoDbDockerSetup dockerSetup)
19 |         {
20 |             _dockerSetup = dockerSetup;
21 |             var cfg = new AmazonDynamoDBConfig { ServiceURL = DynamoDbDockerSetup.ConnectionString };
22 |             var provisioner = new LockTableProvisioner(DynamoDbDockerSetup.Credentials, cfg, "lock-tests", new NullLoggerFactory());
23 |             var tracker = new LocalLockTracker();
24 |             var heartbeatDispatcher = new HeartbeatDispatcher(DynamoDbDockerSetup.Credentials, cfg, tracker, "lock-tests", new NullLoggerFactory());
25 |             _subject = new DynamoDbLockManager(DynamoDbDockerSetup.Credentials, cfg, "lock-tests", provisioner, heartbeatDispatcher, tracker, new NullLoggerFactory(), _leaseTime, _heartbeat);
26 |         }
27 |         
28 |         [Fact]
29 |         public async void should_lock_resource()
30 |         {
31 |             var lockId = Guid.NewGuid().ToString();
32 | 
33 |             await _subject.Start();
34 |             var first = await _subject.AcquireLock(lockId);
35 |             var second = await _subject.AcquireLock(lockId);
36 |             await _subject.Stop();
37 | 
38 |             Assert.True(first);
39 |             Assert.False(second);
40 |         }
41 | 
42 |         [Fact]
43 |         public async void should_release_lock()
44 |         {
45 |             var lockId = Guid.NewGuid().ToString();
46 | 
47 |             await _subject.Start();
48 |             var first = await _subject.AcquireLock(lockId);
49 |             await _subject.ReleaseLock(lockId);
50 |             var second = await _subject.AcquireLock(lockId);
51 |             await _subject.Stop();
52 | 
53 |             Assert.True(first);
54 |             Assert.True(second);
55 |         }
56 | 
57 |         [Fact]
58 |         public async void should_renew_lock_when_heartbeat_active()
59 |         {
60 |             var lockId = Guid.NewGuid().ToString();
61 | 
62 |             await _subject.Start();
63 |             var first = await _subject.AcquireLock(lockId);
64 |             await Task.Delay(TimeSpan.FromSeconds(_leaseTime + 2));
65 |             var second = await _subject.AcquireLock(lockId);
66 |             await _subject.Stop();
67 | 
68 |             Assert.True(first);
69 |             Assert.False(second);
70 |         }
71 | 
72 |         [Fact]
73 |         public async void should_expire_lock_when_heartbeat_inactive()
74 |         {
75 |             var lockId = Guid.NewGuid().ToString();
76 | 
77 |             await _subject.Start();
78 |             var first = await _subject.AcquireLock(lockId);
79 |             await _subject.Stop();
80 |             await Task.Delay(TimeSpan.FromSeconds(_leaseTime + 2));
81 |             await _subject.Start();
82 |             var second = await _subject.AcquireLock(lockId);
83 |             await _subject.Stop();
84 | 
85 |             Assert.True(first);
86 |             Assert.True(second);
87 |         }
88 |     }
89 | }
90 | 


--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
 1 | 
 2 | # DynamoLock
 3 | 
 4 | DynamoLock is a client library for .Net Standard that implements a distributed lock manager on top of Amazon DynamoDB.
 5 | 
 6 | 
 7 | ## Installing
 8 | 
 9 | Using Nuget package console
10 | ```
11 | PM> Install-Package DynamoLock
12 | ```
13 | Using .NET CLI
14 | ```
15 | dotnet add package DynamoLock
16 | ```
17 | 
18 | 
19 | ## How it works
20 | 
21 | When you successfully acquire a lock, an entry is written to a table in DynamoDB that indicates the owner of the lock and the expiry time.
22 | The default lease time is 30 seconds, each node will also send a heartbeat every 10 seconds that will renew any active leases for 30 seconds from the time of the heartbeat.
23 | Once the expiry time has elapsed or the owning node releases the lock, it becomes available again.
24 | 
25 | ## Usage
26 | 
27 | 1. Construct a singleton of DynamoDbLockManager, using one of the overloaded constructors
28 | 
29 | 	```c#
30 | 	using DynamoLock;
31 |     ...
32 | 	var lockManager = DynamoDbLockManager(new EnvironmentVariablesAWSCredentials(), RegionEndpoint.USWest2, NullLoggerFactory.Instance);
33 | 	```
34 | 
35 | 	```c#
36 | 	using DynamoLock;
37 |     ...
38 | 	var lockManager = DynamoDbLockManager(dynamoClient, NullLoggerFactory.Instance);
39 | 	```
40 | 	
41 | 	Alternatively, an extension method to the IoC abstraction of `IServiceCollection` is provided that will add an implementation of `IDistributedLockManager` to your IoC container.
42 |     ```c#
43 |     using DynamoLock;
44 |     ...
45 | 
46 |     services.AddDynamoLockManager(new EnvironmentVariablesAWSCredentials(), new AmazonDynamoDBConfig() { RegionEndpoint = RegionEndpoint.USWest2 }, "lock_table");
47 | 
48 |     ```
49 | 
50 | 2. Then inject `IDistributedLockManager` into your classes via your IoC container of choice.
51 | 3. When your application starts up, you will also need to call the `.Start` method in order to provision the table and start the background heartbeat service.
52 |     ```c#
53 |     IDistributedLockManager lockerManager;
54 |     ...
55 |     lockManager.Start();
56 |     ```
57 |     This will automatically provision the table in DynamoDB if it does not exist and will enable sending a heartbeat every 10 seconds for any locks that have been acquired with the local manager, and renew their leases for a further 30 seconds, until `ReleaseLock` is called for a given resource.
58 |     The table will be created with through put units of 1 by default, you can change these values on the AWS console after the fact.
59 | 
60 | 4. Use the `AcquireLock` and `ReleaseLock` methods to manage your distributed locks.
61 | 
62 |     ```c#
63 |     IDistributedLockManager lockerManager;
64 |     ...
65 |     var success = await lockManager.AcquireLock("my-lock-id");
66 |     ...
67 |     await lockManager.ReleaseLock("my-lock-id");
68 |     ```
69 | 
70 |     `AcquireLock` will return `false` if the lock is already in use and `true` if it successfully acquired the lock.
71 |     It will start with an initial lease of 30 seconds, and a background thread will renew all locally controlled leases every 10 seconds, until `ReleaseLock` is called or the application ends and the leases expire naturally.
72 | 
73 | ### Notes
74 | 
75 | It is recommended that you keep the clocks of all participating nodes in sync using an NTP implementation
76 | 
77 | * https://en.wikipedia.org/wiki/Network_Time_Protocol
78 | * https://aws.amazon.com/blogs/aws/keeping-time-with-amazon-time-sync-service/
79 | 
80 | ## Authors
81 |  * **Daniel Gerlag** - daniel@gerlag.ca
82 | 
83 | ## License
84 | 
85 | This project is licensed under the MIT License - see the [LICENSE](LICENSE.md) file for details
86 | 


--------------------------------------------------------------------------------
/DynamoLock/LockTableProvisioner.cs:
--------------------------------------------------------------------------------
  1 | using System;
  2 | using System.Collections.Generic;
  3 | using System.Text;
  4 | using System.Threading.Tasks;
  5 | using Amazon.DynamoDBv2;
  6 | using Amazon.DynamoDBv2.Model;
  7 | using Amazon.Runtime;
  8 | using Microsoft.Extensions.Logging;
  9 | 
 10 | namespace DynamoLock
 11 | {
 12 |     public class LockTableProvisioner : ILockTableProvisioner
 13 |     {
 14 |         private readonly ILogger _logger;
 15 |         private readonly IAmazonDynamoDB _client;
 16 |         private readonly string _tableName;
 17 | 
 18 |         public LockTableProvisioner(AWSCredentials credentials, AmazonDynamoDBConfig config, string tableName, ILoggerFactory logFactory)
 19 |         {
 20 |             _logger = logFactory.CreateLogger<LockTableProvisioner>();
 21 |             _client = new AmazonDynamoDBClient(credentials, config);
 22 |             _tableName = tableName;
 23 |         }
 24 | 
 25 |         public LockTableProvisioner(IAmazonDynamoDB dynamoClient, string tableName, ILoggerFactory logFactory)
 26 |         {
 27 |             _logger = logFactory.CreateLogger<LockTableProvisioner>();
 28 |             _client = dynamoClient;
 29 |             _tableName = tableName;
 30 |         }
 31 | 
 32 |         public async Task Provision()
 33 |         {
 34 |             try
 35 |             {
 36 |                 var poll = await _client.DescribeTableAsync(_tableName);
 37 |             }
 38 |             catch (ResourceNotFoundException)
 39 |             {
 40 |                 _logger.LogInformation($"Creating lock table {_tableName}");
 41 |                 await CreateTable();
 42 |                 await SetPurgeTTL();
 43 |             }
 44 |         }
 45 | 
 46 |         private async Task CreateTable()
 47 |         {
 48 |             var createRequest = new CreateTableRequest(_tableName, new List<KeySchemaElement>()
 49 |             {
 50 |                 new KeySchemaElement("id", KeyType.HASH)
 51 |             })
 52 |             {
 53 |                 AttributeDefinitions = new List<AttributeDefinition>()
 54 |                 {
 55 |                     new AttributeDefinition("id", ScalarAttributeType.S)
 56 |                 },
 57 |                 ProvisionedThroughput = new ProvisionedThroughput()
 58 |                 {
 59 |                     ReadCapacityUnits = 1,
 60 |                     WriteCapacityUnits = 1
 61 |                 }
 62 |                 //BillingMode = BillingMode.PAY_PER_REQUEST
 63 |             };
 64 | 
 65 |             var createResponse = await _client.CreateTableAsync(createRequest);
 66 |             
 67 |             int i = 0;
 68 |             bool created = false;
 69 |             while ((i < 20) && (!created))
 70 |             {
 71 |                 try
 72 |                 {
 73 |                     await Task.Delay(1000);
 74 |                     var poll = await _client.DescribeTableAsync(_tableName);
 75 |                     created = (poll.Table.TableStatus == TableStatus.ACTIVE);
 76 |                     i++;
 77 |                 }
 78 |                 catch (ResourceNotFoundException)
 79 |                 {
 80 |                 }
 81 |             }
 82 |         }
 83 | 
 84 |         private async Task SetPurgeTTL()
 85 |         {
 86 |             var request = new UpdateTimeToLiveRequest()
 87 |             {
 88 |                 TableName = _tableName,
 89 |                 TimeToLiveSpecification = new TimeToLiveSpecification()
 90 |                 {
 91 |                     AttributeName = "purge_time",
 92 |                     Enabled = true
 93 |                 }
 94 |             };
 95 | 
 96 |             await _client.UpdateTimeToLiveAsync(request);
 97 |         }
 98 |     }
 99 | }
100 | 


--------------------------------------------------------------------------------
/DynamoLock/HeartbeatDispatcher.cs:
--------------------------------------------------------------------------------
  1 | using System;
  2 | using System.Collections.Generic;
  3 | using System.Text;
  4 | using System.Threading;
  5 | using System.Threading.Tasks;
  6 | using Amazon.DynamoDBv2;
  7 | using Amazon.DynamoDBv2.Model;
  8 | using Amazon.Runtime;
  9 | using Microsoft.Extensions.Logging;
 10 | 
 11 | namespace DynamoLock
 12 | {
 13 |     public class HeartbeatDispatcher : IHeartbeatDispatcher
 14 |     {
 15 |         private readonly ILogger _logger;
 16 |         private readonly IAmazonDynamoDB _client;
 17 |         private readonly ILocalLockTracker _lockTracker;
 18 |         private readonly string _tableName;
 19 | 
 20 |         private TimeSpan _interval;
 21 |         private string _nodeId;
 22 |         private long _leaseTime;
 23 |         private Task _heartbeatTask;
 24 |         private CancellationTokenSource _cancellationTokenSource;
 25 | 
 26 |         public HeartbeatDispatcher(AWSCredentials credentials, AmazonDynamoDBConfig config, ILocalLockTracker lockTracker, string tableName, ILoggerFactory logFactory)
 27 |         {
 28 |             _logger = logFactory.CreateLogger<HeartbeatDispatcher>();
 29 |             _client = new AmazonDynamoDBClient(credentials, config);
 30 |             _tableName = tableName;
 31 |             _lockTracker = lockTracker;
 32 |         }
 33 | 
 34 |         public HeartbeatDispatcher(IAmazonDynamoDB dynamoClient, ILocalLockTracker lockTracker, string tableName, ILoggerFactory logFactory)
 35 |         {
 36 |             _logger = logFactory.CreateLogger<HeartbeatDispatcher>();
 37 |             _client = dynamoClient;
 38 |             _tableName = tableName;
 39 |             _lockTracker = lockTracker;
 40 |         }
 41 | 
 42 |         public void Start(string nodeId, TimeSpan interval, long leaseTime)
 43 |         {
 44 |             _nodeId = nodeId;
 45 |             _interval = interval;
 46 |             _leaseTime = leaseTime;
 47 | 
 48 |             if (_cancellationTokenSource != null)
 49 |             {
 50 |                 _cancellationTokenSource.Cancel();
 51 |                 _heartbeatTask?.Wait();
 52 |             }
 53 | 
 54 |             _cancellationTokenSource = new CancellationTokenSource();
 55 |             _heartbeatTask = new Task(SendHeartbeat);
 56 |             _heartbeatTask.Start();
 57 |         }
 58 | 
 59 |         public void Stop()
 60 |         {
 61 |             _cancellationTokenSource?.Cancel();
 62 |             _heartbeatTask?.Wait();
 63 |         }
 64 | 
 65 |         private async void SendHeartbeat()
 66 |         {
 67 |             while (!_cancellationTokenSource.IsCancellationRequested)
 68 |             {
 69 |                 try
 70 |                 {
 71 |                     await Task.Delay(_interval, _cancellationTokenSource.Token);
 72 | 
 73 |                     foreach (var item in _lockTracker.GetSnapshot())
 74 |                     {
 75 |                         var req = new PutItemRequest
 76 |                         {
 77 |                             TableName = _tableName,
 78 |                             Item = new Dictionary<string, AttributeValue>
 79 |                             {
 80 |                                 { "id", new AttributeValue(item) },
 81 |                                 { "lock_owner", new AttributeValue(_nodeId) },
 82 |                                 {
 83 |                                     "expires", new AttributeValue()
 84 |                                     {
 85 |                                         N = Convert.ToString(new DateTimeOffset(DateTime.UtcNow).ToUnixTimeSeconds() + _leaseTime)
 86 |                                     }
 87 |                                 },
 88 |                                 {
 89 |                                     "purge_time", new AttributeValue()
 90 |                                     {
 91 |                                         N = Convert.ToString(new DateTimeOffset(DateTime.UtcNow).ToUnixTimeSeconds() + (_leaseTime * 10))
 92 |                                     }
 93 |                                 }
 94 |                             },
 95 |                             ConditionExpression = "lock_owner = :node_id",
 96 |                             ExpressionAttributeValues = new Dictionary<string, AttributeValue>
 97 |                             {
 98 |                                 { ":node_id", new AttributeValue(_nodeId) }
 99 |                             }
100 |                         };
101 | 
102 |                         try
103 |                         {
104 |                             await _client.PutItemAsync(req, _cancellationTokenSource.Token);
105 |                         }
106 |                         catch (ConditionalCheckFailedException)
107 |                         {
108 |                             _logger.LogWarning($"Lock not owned anymore when sending heartbeat for {item}");
109 |                         }
110 |                     }
111 |                 }
112 |                 catch (Exception ex)
113 |                 {
114 |                     _logger.LogError(default(EventId), ex, ex.Message);
115 |                 }
116 |             }
117 |         }
118 |     }
119 | }
120 | 


--------------------------------------------------------------------------------
/.gitignore:
--------------------------------------------------------------------------------
  1 | ## Ignore Visual Studio temporary files, build results, and
  2 | ## files generated by popular Visual Studio add-ons.
  3 | 
  4 | # User-specific files
  5 | *.suo
  6 | *.user
  7 | *.userosscache
  8 | *.sln.docstates
  9 | 
 10 | # User-specific files (MonoDevelop/Xamarin Studio)
 11 | *.userprefs
 12 | 
 13 | # Build results
 14 | [Dd]ebug/
 15 | [Dd]ebugPublic/
 16 | [Rr]elease/
 17 | [Rr]eleases/
 18 | [Xx]64/
 19 | [Xx]86/
 20 | [Bb]uild/
 21 | bld/
 22 | [Bb]in/
 23 | [Oo]bj/
 24 | 
 25 | # Visual Studio 2015 cache/options directory
 26 | .vs/
 27 | # Uncomment if you have tasks that create the project's static files in wwwroot
 28 | #wwwroot/
 29 | 
 30 | # MSTest test Results
 31 | [Tt]est[Rr]esult*/
 32 | [Bb]uild[Ll]og.*
 33 | 
 34 | # NUNIT
 35 | *.VisualState.xml
 36 | TestResult.xml
 37 | 
 38 | # Build Results of an ATL Project
 39 | [Dd]ebugPS/
 40 | [Rr]eleasePS/
 41 | dlldata.c
 42 | 
 43 | # DNX
 44 | project.lock.json
 45 | artifacts/
 46 | 
 47 | *_i.c
 48 | *_p.c
 49 | *_i.h
 50 | *.ilk
 51 | *.meta
 52 | *.obj
 53 | *.pch
 54 | *.pdb
 55 | *.pgc
 56 | *.pgd
 57 | *.rsp
 58 | *.sbr
 59 | *.tlb
 60 | *.tli
 61 | *.tlh
 62 | *.tmp
 63 | *.tmp_proj
 64 | *.log
 65 | *.vspscc
 66 | *.vssscc
 67 | .builds
 68 | *.pidb
 69 | *.svclog
 70 | *.scc
 71 | 
 72 | # Chutzpah Test files
 73 | _Chutzpah*
 74 | 
 75 | # Visual C++ cache files
 76 | ipch/
 77 | *.aps
 78 | *.ncb
 79 | *.opendb
 80 | *.opensdf
 81 | *.sdf
 82 | *.cachefile
 83 | *.VC.db
 84 | 
 85 | # Visual Studio profiler
 86 | *.psess
 87 | *.vsp
 88 | *.vspx
 89 | *.sap
 90 | 
 91 | # TFS 2012 Local Workspace
 92 | $tf/
 93 | 
 94 | # Guidance Automation Toolkit
 95 | *.gpState
 96 | 
 97 | # ReSharper is a .NET coding add-in
 98 | _ReSharper*/
 99 | *.[Rr]e[Ss]harper
100 | *.DotSettings.user
101 | 
102 | # JustCode is a .NET coding add-in
103 | .JustCode
104 | 
105 | # TeamCity is a build add-in
106 | _TeamCity*
107 | 
108 | # DotCover is a Code Coverage Tool
109 | *.dotCover
110 | 
111 | # NCrunch
112 | _NCrunch_*
113 | .*crunch*.local.xml
114 | nCrunchTemp_*
115 | 
116 | # MightyMoose
117 | *.mm.*
118 | AutoTest.Net/
119 | 
120 | # Web workbench (sass)
121 | .sass-cache/
122 | 
123 | # Installshield output folder
124 | [Ee]xpress/
125 | 
126 | # DocProject is a documentation generator add-in
127 | DocProject/buildhelp/
128 | DocProject/Help/*.HxT
129 | DocProject/Help/*.HxC
130 | DocProject/Help/*.hhc
131 | DocProject/Help/*.hhk
132 | DocProject/Help/*.hhp
133 | DocProject/Help/Html2
134 | DocProject/Help/html
135 | 
136 | # Click-Once directory
137 | publish/
138 | 
139 | # Publish Web Output
140 | *.[Pp]ublish.xml
141 | *.azurePubxml
142 | 
143 | # TODO: Un-comment the next line if you do not want to checkin 
144 | # your web deploy settings because they may include unencrypted
145 | # passwords
146 | #*.pubxml
147 | *.publishproj
148 | 
149 | # NuGet Packages
150 | *.nupkg
151 | # The packages folder can be ignored because of Package Restore
152 | **/packages/*
153 | # except build/, which is used as an MSBuild target.
154 | !**/packages/build/
155 | # Uncomment if necessary however generally it will be regenerated when needed
156 | #!**/packages/repositories.config
157 | # NuGet v3's project.json files produces more ignoreable files
158 | *.nuget.props
159 | *.nuget.targets
160 | 
161 | # Microsoft Azure Build Output
162 | csx/
163 | *.build.csdef
164 | 
165 | # Microsoft Azure Emulator
166 | ecf/
167 | rcf/
168 | 
169 | # Microsoft Azure ApplicationInsights config file
170 | ApplicationInsights.config
171 | 
172 | # Windows Store app package directory
173 | AppPackages/
174 | BundleArtifacts/
175 | 
176 | # Visual Studio cache files
177 | # files ending in .cache can be ignored
178 | *.[Cc]ache
179 | # but keep track of directories ending in .cache
180 | !*.[Cc]ache/
181 | 
182 | # Others
183 | ClientBin/
184 | [Ss]tyle[Cc]op.*
185 | ~$*
186 | *~
187 | *.dbmdl
188 | *.dbproj.schemaview
189 | *.pfx
190 | *.publishsettings
191 | node_modules/
192 | orleans.codegen.cs
193 | 
194 | # RIA/Silverlight projects
195 | Generated_Code/
196 | 
197 | # Backup & report files from converting an old project file
198 | # to a newer Visual Studio version. Backup files are not needed,
199 | # because we have git ;-)
200 | _UpgradeReport_Files/
201 | Backup*/
202 | UpgradeLog*.XML
203 | UpgradeLog*.htm
204 | 
205 | # SQL Server files
206 | *.mdf
207 | *.ldf
208 | 
209 | # Business Intelligence projects
210 | *.rdl.data
211 | *.bim.layout
212 | *.bim_*.settings
213 | 
214 | # Microsoft Fakes
215 | FakesAssemblies/
216 | 
217 | # GhostDoc plugin setting file
218 | *.GhostDoc.xml
219 | 
220 | # Node.js Tools for Visual Studio
221 | .ntvs_analysis.dat
222 | 
223 | # Visual Studio 6 build log
224 | *.plg
225 | 
226 | # Visual Studio 6 workspace options file
227 | *.opt
228 | 
229 | # Visual Studio LightSwitch build output
230 | **/*.HTMLClient/GeneratedArtifacts
231 | **/*.DesktopClient/GeneratedArtifacts
232 | **/*.DesktopClient/ModelManifest.xml
233 | **/*.Server/GeneratedArtifacts
234 | **/*.Server/ModelManifest.xml
235 | _Pvt_Extensions
236 | 
237 | # LightSwitch generated files
238 | GeneratedArtifacts/
239 | ModelManifest.xml
240 | 
241 | # Paket dependency manager
242 | .paket/paket.exe
243 | 
244 | # FAKE - F# Make
245 | .fake/
246 | *.migration_in_place_backup
247 | .idea/.idea.WorkflowCore/.idea
248 | riderModule.iml
249 | 


--------------------------------------------------------------------------------
/Docker.Testify/DockerSetup.cs:
--------------------------------------------------------------------------------
  1 | using Docker.DotNet;
  2 | using Docker.DotNet.Models;
  3 | using System;
  4 | using System.Collections.Generic;
  5 | using System.Diagnostics;
  6 | using System.IO;
  7 | using System.Linq;
  8 | using System.Net.NetworkInformation;
  9 | using System.Runtime.InteropServices;
 10 | using System.Text;
 11 | using System.Threading;
 12 | using System.Threading.Tasks;
 13 | 
 14 | namespace Docker.Testify
 15 | {
 16 |     public abstract class DockerSetup : IDisposable
 17 |     {
 18 |         public abstract string ImageName { get; }
 19 |         public virtual string ContainerPrefix => "tests";
 20 |         public abstract int InternalPort { get; }
 21 | 
 22 |         public virtual string ImageTag => "latest";
 23 |         public virtual TimeSpan TimeOut => TimeSpan.FromSeconds(30);
 24 |         public virtual IList<string> EnvironmentVariables => new List<string>();
 25 |         public int ExternalPort { get; }
 26 | 
 27 |         public abstract bool TestReady();
 28 |         public abstract void PublishConnectionInfo();
 29 | 
 30 |         protected readonly DockerClient docker;
 31 |     	protected string containerId;
 32 | 
 33 |         protected DockerSetup()
 34 |         {
 35 |             if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
 36 |     			docker = new DockerClientConfiguration(new Uri("npipe://./pipe/docker_engine")).CreateClient();
 37 |     		else
 38 |     			docker = new DockerClientConfiguration(new Uri("unix:///var/run/docker.sock")).CreateClient();
 39 | 
 40 |             ExternalPort = GetFreePort();
 41 | 
 42 |             Debug.WriteLine($"Selected port {ExternalPort}");
 43 | 
 44 |             StartContainer().Wait();
 45 |     	}
 46 | 
 47 |         public async Task StartContainer()
 48 |         {
 49 |             var hostCfg = new HostConfig();
 50 |             var pb = new PortBinding
 51 |             {
 52 |                 HostIP = "0.0.0.0",
 53 |                 HostPort = ExternalPort.ToString()
 54 |             };
 55 | 
 56 |             hostCfg.PortBindings = new Dictionary<string, IList<PortBinding>>();
 57 |             hostCfg.PortBindings.Add($"{InternalPort}/tcp", new PortBinding[] { pb });
 58 | 
 59 |             await PullImage(ImageName, ImageTag);	        
 60 | 
 61 |             var container = await docker.Containers.CreateContainerAsync(new CreateContainerParameters()
 62 |             {
 63 |                 Image = $"{ImageName}:{ImageTag}",
 64 |                 Name = $"{ContainerPrefix}-{Guid.NewGuid()}",
 65 |                 HostConfig = hostCfg,
 66 |                 Env = EnvironmentVariables
 67 |             });
 68 | 
 69 |             Debug.WriteLine("Starting docker container...");
 70 |             var started = await docker.Containers.StartContainerAsync(container.ID, new ContainerStartParameters());
 71 |             if (started)
 72 |             {
 73 |                 containerId = container.ID;
 74 |                 PublishConnectionInfo();
 75 | 
 76 |                 Debug.WriteLine("Waiting service to start in the docker container...");
 77 |                 
 78 |                 var ready = false;
 79 |                 var expiryTime = DateTime.Now.Add(TimeOut);
 80 | 
 81 |                 while ((DateTime.Now < expiryTime) && (!ready))
 82 |                 {
 83 |                     await Task.Delay(1000);
 84 |                     ready = TestReady();
 85 |                 }
 86 | 
 87 |                 if (ready)
 88 |                 {
 89 |                     Debug.WriteLine($"Docker container started: {container.ID}");
 90 |                 }
 91 |                 else
 92 |                 {
 93 |                     Debug.WriteLine("Docker container timeout waiting for service");
 94 |                     throw new TimeoutException();
 95 |                 }
 96 |             }
 97 |             else
 98 |             {
 99 |                 Debug.WriteLine("Docker container failed");
100 |             }
101 |         }
102 | 
103 |         public async Task PullImage(string name, string tag)
104 |         {
105 |             var images = docker.Images.ListImagesAsync(new ImagesListParameters()).Result;
106 |             var exists = images
107 |                 .Where(x => x.RepoTags != null)
108 |                 .Any(x => x.RepoTags.Contains($"{name}:{tag}"));
109 | 
110 |             if (exists)
111 |                 return;
112 | 
113 |             Debug.WriteLine($"Pulling docker image {name}:{tag}");
114 |             await docker.Images.CreateImageAsync(new ImagesCreateParameters() { FromImage = name, Tag = tag }, null, new Progress<JSONMessage>());
115 |         }
116 | 
117 |         public void Dispose()
118 |     	{
119 |     	    docker.Containers.KillContainerAsync(containerId, new ContainerKillParameters()).Wait();
120 |     	    docker.Containers.RemoveContainerAsync(containerId, new ContainerRemoveParameters() { Force = true }).Wait();
121 |     	}
122 | 
123 |         private int GetFreePort()
124 |         {
125 |             const int startRange = 1000;
126 |             const int endRange = 10000;
127 |             var ipGlobalProperties = IPGlobalProperties.GetIPGlobalProperties();
128 |             var tcpPorts = ipGlobalProperties.GetActiveTcpListeners();
129 |             var udpPorts = ipGlobalProperties.GetActiveUdpListeners();
130 | 
131 |             var result = startRange;
132 | 
133 |             while (((tcpPorts.Any(x => x.Port == result)) || (udpPorts.Any(x => x.Port == result))) && result <= endRange)
134 |                 result++;
135 | 
136 |             if (result > endRange)
137 |                 throw new PortsInUseException();
138 | 
139 |             return result;
140 | 	    }
141 |     }
142 | }
143 | 


--------------------------------------------------------------------------------
/DynamoLock/DynamoDbLockManager.cs:
--------------------------------------------------------------------------------
  1 | using System;
  2 | using System.Collections.Generic;
  3 | using System.Threading;
  4 | using System.Threading.Tasks;
  5 | using Amazon;
  6 | using Amazon.DynamoDBv2;
  7 | using Amazon.DynamoDBv2.Model;
  8 | using Amazon.Runtime;
  9 | using Microsoft.Extensions.Logging;
 10 | using Microsoft.Extensions.Logging.Abstractions;
 11 | 
 12 | namespace DynamoLock
 13 | {
 14 |     public class DynamoDbLockManager : IDistributedLockManager
 15 |     {
 16 |         private readonly ILogger _logger;
 17 |         private readonly IAmazonDynamoDB _client;
 18 |         private readonly ILockTableProvisioner _provisioner;
 19 |         private readonly IHeartbeatDispatcher _heartbeatDispatcher;
 20 |         private readonly ILocalLockTracker _lockTracker;
 21 |         private readonly string _tableName;
 22 |         private readonly string _nodeId = Guid.NewGuid().ToString();
 23 |         private readonly long _defaultLeaseTime = 30;
 24 |         private readonly TimeSpan _heartbeat = TimeSpan.FromSeconds(10);
 25 |         private readonly long _jitterTolerance = 1;
 26 |         
 27 | 
 28 |         public DynamoDbLockManager(AWSCredentials credentials, AmazonDynamoDBConfig config, string tableName, ILockTableProvisioner provisioner, IHeartbeatDispatcher heartbeatDispatcher, ILocalLockTracker lockTracker, ILoggerFactory logFactory)
 29 |         {
 30 |             _logger = logFactory.CreateLogger<DynamoDbLockManager>();
 31 |             _client = new AmazonDynamoDBClient(credentials, config);
 32 |             _tableName = tableName;
 33 |             _provisioner = provisioner;
 34 |             _heartbeatDispatcher = heartbeatDispatcher;
 35 |             _lockTracker = lockTracker;
 36 |         }
 37 | 
 38 |         public DynamoDbLockManager(AWSCredentials credentials, RegionEndpoint region, string tableName, ILoggerFactory logFactory)
 39 |         {
 40 |             _logger = logFactory.CreateLogger<DynamoDbLockManager>();
 41 |             _client = new AmazonDynamoDBClient(credentials, region);
 42 |             _tableName = tableName;
 43 |             _lockTracker = new LocalLockTracker();
 44 |             _provisioner = new LockTableProvisioner(credentials, new AmazonDynamoDBConfig() { RegionEndpoint = region }, tableName, logFactory);
 45 |             _heartbeatDispatcher = new HeartbeatDispatcher(credentials, new AmazonDynamoDBConfig() {RegionEndpoint = region}, _lockTracker, tableName, logFactory);
 46 |         }
 47 | 
 48 |         public DynamoDbLockManager(IAmazonDynamoDB dynamoClient, string tableName, ILoggerFactory logFactory)
 49 |         {
 50 |             _logger = logFactory.CreateLogger<DynamoDbLockManager>();
 51 |             _client = dynamoClient;
 52 |             _tableName = tableName;
 53 |             _lockTracker = new LocalLockTracker();
 54 |             _provisioner = new LockTableProvisioner(dynamoClient, tableName, logFactory);
 55 |             _heartbeatDispatcher = new HeartbeatDispatcher(dynamoClient, _lockTracker, tableName, logFactory);
 56 |         }
 57 | 
 58 |         public DynamoDbLockManager(AWSCredentials credentials, AmazonDynamoDBConfig config, string tableName, ILockTableProvisioner provisioner, IHeartbeatDispatcher heartbeatDispatcher, ILocalLockTracker lockTracker, ILoggerFactory logFactory, long defaultLeaseTime, TimeSpan hearbeat)
 59 |             : this(credentials, config, tableName, provisioner, heartbeatDispatcher, lockTracker, logFactory)
 60 |         {
 61 |             _defaultLeaseTime = defaultLeaseTime;
 62 |             _heartbeat = hearbeat;
 63 |         }
 64 | 
 65 |         public async Task<bool> AcquireLock(string Id)
 66 |         {
 67 |             try
 68 |             {
 69 |                 var req = new PutItemRequest()
 70 |                 {
 71 |                     TableName = _tableName,
 72 |                     Item = new Dictionary<string, AttributeValue>
 73 |                     {
 74 |                         { "id", new AttributeValue(Id) },
 75 |                         { "lock_owner", new AttributeValue(_nodeId) },
 76 |                         {
 77 |                             "expires", new AttributeValue()
 78 |                             {
 79 |                                 N = Convert.ToString(new DateTimeOffset(DateTime.UtcNow).ToUnixTimeSeconds() + _defaultLeaseTime)
 80 |                             }
 81 |                         },
 82 |                         {
 83 |                             "purge_time", new AttributeValue()
 84 |                             {
 85 |                                 N = Convert.ToString(new DateTimeOffset(DateTime.UtcNow).ToUnixTimeSeconds() + (_defaultLeaseTime * 10))
 86 |                             }
 87 |                         }
 88 |                     },
 89 |                     ConditionExpression = "attribute_not_exists(id) OR (expires < :expired)",
 90 |                     ExpressionAttributeValues = new Dictionary<string, AttributeValue>
 91 |                     {
 92 |                         { ":expired", new AttributeValue()
 93 |                             {
 94 |                                 N = Convert.ToString(new DateTimeOffset(DateTime.UtcNow).ToUnixTimeSeconds() + _jitterTolerance)
 95 |                             }
 96 |                         }
 97 |                     }
 98 |                 };
 99 | 
100 |                 var response = await _client.PutItemAsync(req);
101 | 
102 |                 if (response.HttpStatusCode == System.Net.HttpStatusCode.OK)
103 |                 {
104 |                     _lockTracker.Add(Id);
105 |                     return true;
106 |                 }
107 |             }
108 |             catch (ConditionalCheckFailedException)
109 |             {
110 |             }
111 |             return false;
112 |         }
113 | 
114 |         public async Task ReleaseLock(string Id)
115 |         {
116 |             _lockTracker.Remove(Id);
117 |         
118 |             try
119 |             {
120 |                 var req = new DeleteItemRequest()
121 |                 {
122 |                     TableName = _tableName,
123 |                     Key = new Dictionary<string, AttributeValue>
124 |                     {
125 |                         { "id", new AttributeValue(Id) }
126 |                     },
127 |                     ConditionExpression = "lock_owner = :node_id",
128 |                     ExpressionAttributeValues = new Dictionary<string, AttributeValue>
129 |                     {
130 |                         { ":node_id", new AttributeValue(_nodeId) }
131 |                     }
132 | 
133 |                 };
134 |                 await _client.DeleteItemAsync(req);
135 |             }
136 |             catch (ConditionalCheckFailedException)
137 |             {
138 |             }
139 |         }
140 | 
141 |         public async Task Start()
142 |         {
143 |             await _provisioner.Provision();
144 |             _heartbeatDispatcher.Start(_nodeId, _heartbeat, _defaultLeaseTime);
145 |         }
146 | 
147 |         public Task Stop()
148 |         {
149 |             _heartbeatDispatcher.Stop();
150 |             _lockTracker.Clear();
151 |             return Task.CompletedTask;
152 |         }
153 |     }
154 | }
155 | 


--------------------------------------------------------------------------------