diff --git a/FastGithub/DnsHostedService.cs b/FastGithub/DnsHostedService.cs
index 2b1b81f..91d7e5d 100644
--- a/FastGithub/DnsHostedService.cs
+++ b/FastGithub/DnsHostedService.cs
@@ -44,18 +44,16 @@ namespace FastGithub
                 var domain = question.Name.ToString();
                 if (domain.Contains("github", StringComparison.OrdinalIgnoreCase))
                 {
-                    var contexts = this.githubScanService.Result
-                        .Where(item => item.Domain == domain)
-                        .OrderBy(item => item.HttpElapsed);
-
-                    foreach (var context in contexts)
+                    var ttl = TimeSpan.FromMinutes(2d);
+                    var addressArray = this.githubScanService.FindAddress(domain);
+                    foreach (var address in addressArray)
                     {
-                        var record = new IPAddressResourceRecord(question.Name, context.Address, TimeSpan.FromMinutes(2d));
+                        var record = new IPAddressResourceRecord(question.Name, address, ttl);
                         response.AnswerRecords.Add(record);
-                        this.logger.LogWarning(record.ToString());
                     }
 
-                    return Task.FromResult<IResponse>(response);
+                    var addressString = string.Join(',', addressArray.Select(a => a.ToString()));
+                    this.logger.LogInformation($"{domain}=>{addressString}");
                 }
             }
 
diff --git a/FastGithub/GithubContext.cs b/FastGithub/GithubContext.cs
index 5764c9e..ff467e0 100644
--- a/FastGithub/GithubContext.cs
+++ b/FastGithub/GithubContext.cs
@@ -3,15 +3,15 @@ using System.Net;
 
 namespace FastGithub
 {
-    class GithubContext
+    class GithubContext : IEquatable<GithubContext>
     {
-        public string Domain { get;  }
+        public string Domain { get; }
 
-        public IPAddress Address { get;  }
+        public IPAddress Address { get; }
 
         public TimeSpan? HttpElapsed { get; set; }
 
-        public GithubContext(string domain,IPAddress address)
+        public GithubContext(string domain, IPAddress address)
         {
             this.Domain = domain;
             this.Address = address;
@@ -21,5 +21,20 @@ namespace FastGithub
         {
             return $"{Address}\t{Domain}\t# {HttpElapsed}";
         }
+
+        public override bool Equals(object? obj)
+        {
+            return obj is GithubContext other && this.Equals(other);
+        }
+
+        public bool Equals(GithubContext? other)
+        {
+            return other != null && other.Address.Equals(this.Address) && other.Domain == this.Domain;
+        }
+
+        public override int GetHashCode()
+        {
+            return HashCode.Combine(this.Domain, this.Address);
+        }
     }
 }
diff --git a/FastGithub/GithubContextHashSet.cs b/FastGithub/GithubContextHashSet.cs
new file mode 100644
index 0000000..d4bd3f2
--- /dev/null
+++ b/FastGithub/GithubContextHashSet.cs
@@ -0,0 +1,9 @@
+using System.Collections.Generic;
+
+namespace FastGithub
+{
+    class GithubContextHashSet : HashSet<GithubContext>
+    {
+        public readonly object SyncRoot = new();
+    }
+}
diff --git a/FastGithub/GithubScanService.cs b/FastGithub/GithubScanService.cs
index ba6df02..1d2dbe7 100644
--- a/FastGithub/GithubScanService.cs
+++ b/FastGithub/GithubScanService.cs
@@ -1,5 +1,6 @@
-using System.Collections.Concurrent;
+using Microsoft.Extensions.Logging;
 using System.Linq;
+using System.Net;
 using System.Threading;
 using System.Threading.Tasks;
 
@@ -9,15 +10,17 @@ namespace FastGithub
     {
         private readonly GithubMetaService metaService;
         private readonly GithubScanDelegate scanDelegate;
-
-        public ConcurrentQueue<GithubContext> Result { get; } = new();
+        private readonly ILogger<GithubScanService> logger;
+        private readonly GithubContextHashSet results = new();
 
         public GithubScanService(
             GithubMetaService metaService,
-            GithubScanDelegate scanDelegate)
+            GithubScanDelegate scanDelegate,
+            ILogger<GithubScanService> logger)
         {
             this.metaService = metaService;
             this.scanDelegate = scanDelegate;
+            this.logger = logger;
         }
 
         public async Task ScanAllAsync(CancellationToken cancellationToken = default)
@@ -25,26 +28,50 @@ namespace FastGithub
             var meta = await this.metaService.GetMetaAsync(cancellationToken);
             if (meta != null)
             {
-                this.Result.Clear();
                 var scanTasks = meta.ToGithubContexts().Select(ctx => ScanAsync(ctx));
                 await Task.WhenAll(scanTasks);
             }
+
+            this.logger.LogInformation("完全扫描完成");
+
+            async Task ScanAsync(GithubContext context)
+            {
+                await this.scanDelegate(context);
+                if (context.HttpElapsed != null)
+                {
+                    lock (this.results.SyncRoot)
+                    {
+                        this.results.Add(context);
+                    }
+                }
+            }
         }
 
         public async Task ScanResultAsync()
         {
-            while (this.Result.TryDequeue(out var context))
+            GithubContext[] contexts;
+            lock (this.results.SyncRoot)
             {
-                await this.ScanAsync(context);
+                contexts = this.results.ToArray();
             }
+
+            foreach (var context in contexts)
+            {
+                await this.scanDelegate(context);
+            }
+
+            this.logger.LogInformation("结果扫描完成");
         }
 
-        private async Task ScanAsync(GithubContext context)
+        public IPAddress[] FindAddress(string domain)
         {
-            await this.scanDelegate(context);
-            if (context.HttpElapsed != null)
+            lock (this.results.SyncRoot)
             {
-                this.Result.Enqueue(context);
+                return this.results
+                    .Where(item => item.Domain == domain && item.HttpElapsed != null)
+                    .OrderBy(item => item.HttpElapsed)
+                    .Select(item => item.Address)
+                    .ToArray();
             }
         }
     }
diff --git a/FastGithub/Properties/launchSettings.json b/FastGithub/Properties/launchSettings.json
index 2d7291b..b100c0a 100644
--- a/FastGithub/Properties/launchSettings.json
+++ b/FastGithub/Properties/launchSettings.json
@@ -7,7 +7,7 @@
       "launchBrowser": true,
       "environmentVariables": {
         "DOTNET_ENVIRONMENT": "Development",
-        "Logging__LogLevel__Default": "Information"
+        "Logging__LogLevel__Default": "Trace"
       }
     }
   }