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neo4j graph db를 닷넷에서 이용하는 방법을 먼저 알아본후

액터 메시지큐에 그래프db이벤트를 발생시켜, 메시지큐를 통해 이벤트를 추가하는 방법을 알아보겠습니다.


사전셋팅 StandAlone Neo4j

docker-compose를 통해 로컬환경구축이 가능하며, neo4j 프로토콜을 사용하여 초기에 로그인을해주면

사용준비가 끝나게됩니다. 

version: '2'
services:
  neo4j:
    image: bitnami/neo4j:latest   
    ports:
      - '7474:7474'
      - '7473:7473'
      - '7687:7687'


셋팅

의존모듈

<PackageReference Include="Neo4jClient" Version="4.1.14" />
<PackageReference Include="AkkaDotModule.Webnori" Version="1.1.1" />
appsetting.json
{
  "Logging": {
    "LogLevel": {
      "Default": "Debug",
      "System": "Information",
      "Microsoft": "Information"
    }
  },
  "AppSettings": {    
    "GraphConnection": "http://localhost:7474",
    "GraphConnectionUser": "neo4j",
    "GraphConnectionPw": "bitnami"
  }
}
GraphEngine
using Neo4jClient;
using Neo4jClient.Cypher;

    public class GraphEngine
    {
        private readonly AppSettings appSettings;

        private readonly ILogger logger;

        private readonly GraphClient neo4jClient;

        public GraphEngine(AppSettings _appSettings, ILogger<GraphEngine> _logger)
        {
            appSettings = _appSettings;            
            logger = _logger;
            neo4jClient = new GraphClient(new Uri(appSettings.GraphConnection), appSettings.GraphConnectionUser, appSettings.GraphConnectionPw);            
        }

        public async Task<ICypherFluentQuery> GetCypher()
        {
            if (!neo4jClient.IsConnected)
            {
                await neo4jClient.ConnectAsync();
            }
            return neo4jClient.Cypher;
        }

        public async Task<GraphClient> GetClient()
        {
            if (!neo4jClient.IsConnected)
            {
                await neo4jClient.ConnectAsync();
            }
            return neo4jClient;
        }

        public async Task RemoveAll()
        {
            var cyper = await GetCypher();

            await cyper
                .Match("(n)")
                .DetachDelete("n")
                .ExecuteWithoutResultsAsync();

        }

    }


DI셋팅
public void ConfigureServices(IServiceCollection services)
{
	services.AddSingleton<GraphEngine>();
}

유닛테스트기를 사용하여 Graph DB활용해보기

UseCase :

  • 홍길동 사용자생성
  • 철수 사용자생성
  • 스파이더맨 영화생성
  • 타이타닉 영화생성
  • 홍길동은 스파이더맨을 보았다
  • 철수는 타이타닉을 보았다
  • 홍길동과 철수 친구연결
namespace SearchApiTest.Adapter
{
    public class GraphEngineTest
    {
        private GraphEngine _graphEngine;

        [SetUp]
        public void SetUp()
        {
            var logger = TestLogger.Create<GraphEngine>();
            var builder = new ConfigurationBuilder()
                .AddJsonFile("appsettings.Development.json");
            var Configuration = builder.Build();

            var options = new AppSettings();
            Configuration.GetSection("AppSettings")
                .Bind(options);
            _graphEngine = new GraphEngine(options, logger);
        }

        [TestCase(TestName = "Step0 - 초기화 생성및 연결 Test")]
        public async Task CreatePersonAreOK()
        {
            _graphEngine.RemoveAll().Wait();

            var cypher = await _graphEngine.GetCypher();

            await cypher.Write
                .Create(@"(alice:Person {name:'홍길동'})")
                .ExecuteWithoutResultsAsync();

            await cypher.Write
                .Create(@"(alice:Person {name:'철수'})")
                .ExecuteWithoutResultsAsync();

            await cypher.Write
                .Create(@"(alice:Movie {name:'스파이더맨'})")
                .ExecuteWithoutResultsAsync();

            await cypher.Write
                .Create(@"(alice:Movie {name:'타이타닉'})")
                .ExecuteWithoutResultsAsync();

            await cypher.Write
                .Match(@"(a: Person),(b: Movie)")
                .Where(@"a.name = '홍길동' AND b.name = '스파이더맨'")
                .Create(@"(a)-[r:뷰]->(b)").ExecuteWithoutResultsAsync();

            await cypher.Write
                .Match(@"(a: Person),(b: Movie)")
                .Where(@"a.name = '철수' AND b.name = '타이타닉'")
                .Create(@"(a)-[r:뷰]->(b)").ExecuteWithoutResultsAsync();

            await cypher.Write
                .Match(@"(a: Person),(b: Person)")
                .Where(@"a.name = '철수' AND b.name = '홍길동'")
                .Create(@"(a)-[r:친구]->(b)").ExecuteWithoutResultsAsync();
        }
    }
}


친구가본 영화를 추천하는 간단한 그래프 모델입니다.


이벤트 큐로 확장하기

서비스에서 이벤트가 발생할때마다 Crud를 직접하는것은 서비스의 성능을 느리게할수 있으며, 발생이벤트를 메시징큐에 적재하여

백그라운드에서 순차적으로 또는 분리된 리모트에서 해당이벤트를 처리할수 있습니다. ( AkkaRemote또는 Kafka가 활용될수 있습니다.)


그래프 이벤트를 처리하는 액터

namespace SearchApi.Actors
{
    public class GraphElementIdenty
    {
        public string Alice { get; set; }

        public string Name { get; set; }
    }

    public class GraphEvent
    {
        public string Action { get; set; } // Create , Relation, Reset

        public string Alice { get; set; } // AliceName

        public string Name { get; set; }

        public GraphElementIdenty From { get; set; }

        public GraphElementIdenty To { get; set; }
    }

    public class GraphEventActor : ReceiveActor
    {
        private readonly ILoggingAdapter logger = Context.GetLogger();        
        private readonly GraphEngine graphEngine;

        public GraphEventActor(GraphEngine _graphEngine)
        {
            logger.Info($"Create GraphEventActor:{Context.Self.Path.Name}");
            graphEngine = _graphEngine;

            ReceiveAsync<GraphEvent>(async graphEvent =>
            {
                var cypher = await _graphEngine.GetCypher();

                switch (graphEvent.Action)
                {
                    case "Reset":
                        {
                            await _graphEngine.RemoveAll();
                        }
                        break;
                    case "Create":
                        {                            
                            await cypher.Write
                                .Create($"(alice:{graphEvent.Alice} {{name:'{graphEvent.Name}'}})")
                                .ExecuteWithoutResultsAsync();
                        }
                        break;
                    case "Relation":
                        {
                            await cypher.Write
                                .Match($"(a:{graphEvent.From.Alice}),(b:{graphEvent.To.Alice})")
                                .Where($"a.name = '{graphEvent.From.Name}' AND b.name = '{graphEvent.To.Name}'")
                                .Create($"(a)-[r:{graphEvent.Name}]->(b)").ExecuteWithoutResultsAsync();
                        }
                        break;
                }
            });
        }
    }
}
Graph 이벤트발생 
var graphEngine = app.ApplicationServices.GetService<GraphEngine>();

var graphEventActor = AkkaLoad.RegisterActor(
    "GraphEventActor",
    actorSystem.ActorOf(Props.Create<GraphEventActor>(graphEngine),
        "GraphEventActor"
));

//Test For Graph
graphEventActor.Tell(new GraphEvent()
{
    Action = "Reset"
});

graphEventActor.Tell(new GraphEvent()
{
    Action = "Create",
    Alice = "Person",
    Name = "홍길동"
});

graphEventActor.Tell(new GraphEvent()
{
    Action = "Create",
    Alice = "Movie",
    Name = "스파이더맨"
});

graphEventActor.Tell(new GraphEvent()
{
    Action = "Relation",                            
    Name = "시청",
    From = new GraphElementIdenty()
    {
        Alice = "Person",
        Name = "홍길동"
    },
    To = new GraphElementIdenty()
    {
        Alice = "Movie",
        Name = "스파이더맨"
    }
});


추가참고 링크


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