perf: use named HttpClient with SocketsHttpHandler connection pooling for Jellyfin backend

allstarr/Program.cs

@@ -176,6 +176,25 @@ builder.Services.ConfigureAll<HttpClientFactoryOptions>(options =>
     // but we want to reduce noise in production logs
     options.SuppressHandlerScope = true;
 });
+
+// Register a dedicated named HttpClient for Jellyfin backend with connection pooling.
+// SocketsHttpHandler reuses TCP connections across the scoped JellyfinProxyService
+// instances, eliminating per-request TCP/TLS handshake overhead.
+builder.Services.AddHttpClient(JellyfinProxyService.HttpClientName)
+    .ConfigurePrimaryHttpMessageHandler(() => new SocketsHttpHandler
+    {
+        // Keep up to 20 idle connections to Jellyfin alive at any time
+        MaxConnectionsPerServer = 20,
+        // Recycle pooled connections every 5 minutes to pick up DNS changes
+        PooledConnectionLifetime = TimeSpan.FromMinutes(5),
+        // Close idle connections after 90 seconds to avoid stale sockets
+        PooledConnectionIdleTimeout = TimeSpan.FromSeconds(90),
+        // Allow HTTP/2 multiplexing when Jellyfin supports it
+        EnableMultipleHttp2Connections = true,
+        // Follow redirects within Jellyfin
+        AllowAutoRedirect = true,
+        MaxAutomaticRedirections = 5
+    });
 builder.Services.AddEndpointsApiExplorer();
 builder.Services.AddSwaggerGen();
 builder.Services.AddHttpContextAccessor();

allstarr/Services/Jellyfin/JellyfinProxyService.cs

@@ -10,9 +10,17 @@ namespace allstarr.Services.Jellyfin;
 
 /// <summary>
 /// Handles proxying requests to the Jellyfin server and authentication.
+/// Uses a named HttpClient ("JellyfinBackend") with SocketsHttpHandler for
+/// TCP connection pooling across scoped instances.
 /// </summary>
 public class JellyfinProxyService
 {
+    /// <summary>
+    /// The IHttpClientFactory registration name for the Jellyfin backend client.
+    /// Configured with SocketsHttpHandler for connection pooling in Program.cs.
+    /// </summary>
+    public const string HttpClientName = "JellyfinBackend";
+
     private readonly HttpClient _httpClient;
     private readonly JellyfinSettings _settings;
     private readonly IHttpContextAccessor _httpContextAccessor;
@@ -31,7 +39,7 @@ public class JellyfinProxyService
         ILogger<JellyfinProxyService> logger,
         RedisCacheService cache)
     {
-        _httpClient = httpClientFactory.CreateClient();
+        _httpClient = httpClientFactory.CreateClient(HttpClientName);
         _settings = settings.Value;
         _httpContextAccessor = httpContextAccessor;
         _logger = logger;