My indexers have been working flawlessly for 3+ years and now they're down about 90% of the time due to this connection error. Sometimes they'll connect and download one or two files, then fail after that. I've updated my server to 6.11.5 and double-checked all my APIs in each client.
Here's an example of the logs I'm getting from Radarr (similar to Sonarr)
[v4.2.4.6635] System.Net.Http.HttpRequestException: Resource temporarily unavailable (api.drunkenslug.com:443) ---> System.Net.Sockets.SocketException (11): Resource temporarily unavailable at System.Net.Sockets.Socket.AwaitableSocketAsyncEventArgs.ThrowException(SocketError error, CancellationToken cancellationToken) at System.Net.Sockets.Socket.AwaitableSocketAsyncEventArgs.System.Threading.Tasks.Sources.IValueTaskSource.GetResult(Int16 token) at System.Net.Sockets.Socket.<ConnectAsync>g__WaitForConnectWithCancellation|277_0(AwaitableSocketAsyncEventArgs saea, ValueTask connectTask, CancellationToken cancellationToken) at NzbDrone.Common.Http.Dispatchers.ManagedHttpDispatcher.attemptConnection(AddressFamily addressFamily, SocketsHttpConnectionContext context, CancellationToken cancellationToken) in D:\a\1\s\src\NzbDrone.Common\Http\Dispatchers\ManagedHttpDispatcher.cs:line 296 at NzbDrone.Common.Http.Dispatchers.ManagedHttpDispatcher.onConnect(SocketsHttpConnectionContext context, CancellationToken cancellationToken) in D:\a\1\s\src\NzbDrone.Common\Http\Dispatchers\ManagedHttpDispatcher.cs:line 272 at System.Net.Http.HttpConnectionPool.ConnectToTcpHostAsync(String host, Int32 port, HttpRequestMessage initialRequest, Boolean async, CancellationToken cancellationToken) --- End of inner exception stack trace --- at System.Net.Http.HttpConnectionPool.ConnectToTcpHostAsync(String host, Int32 port, HttpRequestMessage initialRequest, Boolean async, CancellationToken cancellationToken) at System.Net.Http.HttpConnectionPool.ConnectAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken) at System.Net.Http.HttpConnectionPool.CreateHttp11ConnectionAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken) at System.Net.Http.HttpConnectionPool.AddHttp11ConnectionAsync(HttpRequestMessage request) at System.Threading.Tasks.TaskCompletionSourceWithCancellation`1.WaitWithCancellation(CancellationToken cancellationToken) at System.Net.Http.HttpConnectionPool.GetHttp11ConnectionAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken) at System.Net.Http.HttpConnectionPool.SendWithVersionDetectionAndRetryAsync(HttpRequestMessage request, Boolean async, Boolean doRequestAuth, CancellationToken cancellationToken) at System.Net.Http.AuthenticationHelper.SendWithAuthAsync(HttpRequestMessage request, Uri authUri, Boolean async, ICredentials credentials, Boolean preAuthenticate, Boolean isProxyAuth, Boolean doRequestAuth, HttpConnectionPool pool, CancellationToken cancellationToken) at System.Net.Http.HttpMessageHandlerStage.Send(HttpRequestMessage request, CancellationToken cancellationToken) at System.Net.Http.DiagnosticsHandler.SendAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken) at System.Net.Http.DecompressionHandler.SendAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken) at System.Net.Http.HttpMessageHandlerStage.Send(HttpRequestMessage request, CancellationToken cancellationToken) at System.Net.Http.SocketsHttpHandler.Send(HttpRequestMessage request, CancellationToken cancellationToken) at System.Net.Http.HttpMessageInvoker.Send(HttpRequestMessage request, CancellationToken cancellationToken) at System.Net.Http.HttpClient.Send(HttpRequestMessage request, HttpCompletionOption completionOption, CancellationToken cancellationToken) at NzbDrone.Common.Http.Dispatchers.ManagedHttpDispatcher.GetResponse(HttpRequest request, CookieContainer cookies) in D:\a\1\s\src\NzbDrone.Common\Http\Dispatchers\ManagedHttpDispatcher.cs:line 101 at NzbDrone.Common.Http.HttpClient.ExecuteRequest(HttpRequest request, CookieContainer cookieContainer) in D:\a\1\s\src\NzbDrone.Common\Http\HttpClient.cs:line 124 at NzbDrone.Common.Http.HttpClient.Execute(HttpRequest request) in D:\a\1\s\src\NzbDrone.Common\Http\HttpClient.cs:line 59 at NzbDrone.Core.Indexers.HttpIndexerBase`1.FetchIndexerResponse(IndexerRequest request) in D:\a\1\s\src\NzbDrone.Core\Indexers\HttpIndexerBase.cs:line 309 at NzbDrone.Core.Indexers.HttpIndexerBase`1.FetchPage(IndexerRequest request, IParseIndexerResponse parser) in D:\a\1\s\src\NzbDrone.Core\Indexers\HttpIndexerBase.cs:line 282 at NzbDrone.Core.Indexers.HttpIndexerBase`1.FetchReleases(Func`2 pageableRequestChainSelector, Boolean isRecent) in D:\a\1\s\src\NzbDrone.Core\Indexers\HttpIndexerBase.cs:line 123 FeedUrl: https://api.drunkenslug.com/api?t=movie&cat=2000,2010,2020,2030,2035,2040,2045,2050,2060&extended=1&apikey=(removed)&offset=0&limit=100&imdbid=0092099 2022-12-30 18:58:35.1|Error|Newznab|An error occurred while processing indexer feed. https://api.nzbgeek.info/api?t=movie&cat=2000,2010,2020,2030,2035,2040,2045,2050,2060&extended=1&apikey=(removed)&offset=0&limit=100&imdbid=0092099 [v4.2.4.6635] System.Net.Http.HttpRequestException: Resource temporarily unavailable (api.nzbgeek.info:443) ---> System.Net.Sockets.SocketException (11): Resource temporarily unavailable at System.Net.Sockets.Socket.AwaitableSocketAsyncEventArgs.ThrowException(SocketError error, CancellationToken cancellationToken) at System.Net.Sockets.Socket.AwaitableSocketAsyncEventArgs.System.Threading.Tasks.Sources.IValueTaskSource.GetResult(Int16 token) at System.Net.Sockets.Socket.<ConnectAsync>g__WaitForConnectWithCancellation|277_0(AwaitableSocketAsyncEventArgs saea, ValueTask connectTask, CancellationToken cancellationToken) at NzbDrone.Common.Http.Dispatchers.ManagedHttpDispatcher.attemptConnection(AddressFamily addressFamily, SocketsHttpConnectionContext context, CancellationToken cancellationToken) in D:\a\1\s\src\NzbDrone.Common\Http\Dispatchers\ManagedHttpDispatcher.cs:line 296 at NzbDrone.Common.Http.Dispatchers.ManagedHttpDispatcher.onConnect(SocketsHttpConnectionContext context, CancellationToken cancellationToken) in D:\a\1\s\src\NzbDrone.Common\Http\Dispatchers\ManagedHttpDispatcher.cs:line 272 at System.Net.Http.HttpConnectionPool.ConnectToTcpHostAsync(String host, Int32 port, HttpRequestMessage initialRequest, Boolean async, CancellationToken cancellationToken) --- End of inner exception stack trace --- at System.Net.Http.HttpConnectionPool.ConnectToTcpHostAsync(String host, Int32 port, HttpRequestMessage initialRequest, Boolean async, CancellationToken cancellationToken) at System.Net.Http.HttpConnectionPool.ConnectAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken) at System.Net.Http.HttpConnectionPool.CreateHttp11ConnectionAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken) at System.Net.Http.HttpConnectionPool.AddHttp11ConnectionAsync(HttpRequestMessage request) at System.Threading.Tasks.TaskCompletionSourceWithCancellation`1.WaitWithCancellation(CancellationToken cancellationToken) at System.Net.Http.HttpConnectionPool.GetHttp11ConnectionAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken) at System.Net.Http.HttpConnectionPool.SendWithVersionDetectionAndRetryAsync(HttpRequestMessage request, Boolean async, Boolean doRequestAuth, CancellationToken cancellationToken) at System.Net.Http.AuthenticationHelper.SendWithAuthAsync(HttpRequestMessage request, Uri authUri, Boolean async, ICredentials credentials, Boolean preAuthenticate, Boolean isProxyAuth, Boolean doRequestAuth, HttpConnectionPool pool, CancellationToken cancellationToken) at System.Net.Http.HttpMessageHandlerStage.Send(HttpRequestMessage request, CancellationToken cancellationToken) at System.Net.Http.DiagnosticsHandler.SendAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken) at System.Net.Http.DecompressionHandler.SendAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken) at System.Net.Http.HttpMessageHandlerStage.Send(HttpRequestMessage request, CancellationToken cancellationToken) at System.Net.Http.SocketsHttpHandler.Send(HttpRequestMessage request, CancellationToken cancellationToken) at System.Net.Http.HttpMessageInvoker.Send(HttpRequestMessage request, CancellationToken cancellationToken) at System.Net.Http.HttpClient.Send(HttpRequestMessage request, HttpCompletionOption completionOption, CancellationToken cancellationToken) at NzbDrone.Common.Http.Dispatchers.ManagedHttpDispatcher.GetResponse(HttpRequest request, CookieContainer cookies) in D:\a\1\s\src\NzbDrone.Common\Http\Dispatchers\ManagedHttpDispatcher.cs:line 101 at NzbDrone.Common.Http.HttpClient.ExecuteRequest(HttpRequest request, CookieContainer cookieContainer) in D:\a\1\s\src\NzbDrone.Common\Http\HttpClient.cs:line 124 at NzbDrone.Common.Http.HttpClient.Execute(HttpRequest request) in D:\a\1\s\src\NzbDrone.Common\Http\HttpClient.cs:line 59 at NzbDrone.Core.Indexers.HttpIndexerBase`1.FetchIndexerResponse(IndexerRequest request) in D:\a\1\s\src\NzbDrone.Core\Indexers\HttpIndexerBase.cs:line 309 at NzbDrone.Core.Indexers.HttpIndexerBase`1.FetchPage(IndexerRequest request, IParseIndexerResponse parser) in D:\a\1\s\src\NzbDrone.Core\Indexers\HttpIndexerBase.cs:line 282 at NzbDrone.Core.Indexers.HttpIndexerBase`1.FetchReleases(Func`2 pageableRequestChainSelector, Boolean isRecent) in D:\a\1\s\src\NzbDrone.Core\Indexers\HttpIndexerBase.cs:line 123 FeedUrl: https://api.nzbgeek.info/api?t=movie&cat=2000,2010,2020,2030,2035,2040,2045,2050,2060&extended=1&apikey=(removed)&offset=0&limit=100&imdbid=0092099 2022-12-30 18:58:35.9|Error|Newznab|An error occurred while processing indexer feed. https://www.tabula-rasa.pw/api?t=movie&cat=2000,2010,2020,2030,2035,2040,2045,2050,2060&extended=1&apikey=(removed)&offset=0&limit=100&imdbid=0092099 [v4.2.4.6635] System.Net.Http.HttpRequestException: Resource temporarily unavailable (www.tabula-rasa.pw:443) ---> System.Net.Sockets.SocketException (11): Resource temporarily unavailable at System.Net.Sockets.Socket.AwaitableSocketAsyncEventArgs.ThrowException(SocketError error, CancellationToken cancellationToken) at System.Net.Sockets.Socket.AwaitableSocketAsyncEventArgs.System.Threading.Tasks.Sources.IValueTaskSource.GetResult(Int16 token) at System.Net.Sockets.Socket.<ConnectAsync>g__WaitForConnectWithCancellation|277_0(AwaitableSocketAsyncEventArgs saea, ValueTask connectTask, CancellationToken cancellationToken) at NzbDrone.Common.Http.Dispatchers.ManagedHttpDispatcher.attemptConnection(AddressFamily addressFamily, SocketsHttpConnectionContext context, CancellationToken cancellationToken) in D:\a\1\s\src\NzbDrone.Common\Http\Dispatchers\ManagedHttpDispatcher.cs:line 296 at NzbDrone.Common.Http.Dispatchers.ManagedHttpDispatcher.onConnect(SocketsHttpConnectionContext context, CancellationToken cancellationToken) in D:\a\1\s\src\NzbDrone.Common\Http\Dispatchers\ManagedHttpDispatcher.cs:line 272 at System.Net.Http.HttpConnectionPool.ConnectToTcpHostAsync(String host, Int32 port, HttpRequestMessage initialRequest, Boolean async, CancellationToken cancellationToken) --- End of inner exception stack trace --- at System.Net.Http.HttpConnectionPool.ConnectToTcpHostAsync(String host, Int32 port, HttpRequestMessage initialRequest, Boolean async, CancellationToken cancellationToken) at System.Net.Http.HttpConnectionPool.ConnectAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken) at System.Net.Http.HttpConnectionPool.CreateHttp11ConnectionAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken) at System.Net.Http.HttpConnectionPool.AddHttp11ConnectionAsync(HttpRequestMessage request) at System.Threading.Tasks.TaskCompletionSourceWithCancellation`1.WaitWithCancellation(CancellationToken cancellationToken) at System.Net.Http.HttpConnectionPool.GetHttp11ConnectionAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken) at System.Net.Http.HttpConnectionPool.SendWithVersionDetectionAndRetryAsync(HttpRequestMessage request, Boolean async, Boolean doRequestAuth, CancellationToken cancellationToken) at System.Net.Http.AuthenticationHelper.SendWithAuthAsync(HttpRequestMessage request, Uri authUri, Boolean async, ICredentials credentials, Boolean preAuthenticate, Boolean isProxyAuth, Boolean doRequestAuth, HttpConnectionPool pool, CancellationToken cancellationToken) at System.Net.Http.HttpMessageHandlerStage.Send(HttpRequestMessage request, CancellationToken cancellationToken) at System.Net.Http.DiagnosticsHandler.SendAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken) at System.Net.Http.DecompressionHandler.SendAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken) at System.Net.Http.HttpMessageHandlerStage.Send(HttpRequestMessage request, CancellationToken cancellationToken) at System.Net.Http.SocketsHttpHandler.Send(HttpRequestMessage request, CancellationToken cancellationToken) at System.Net.Http.HttpMessageInvoker.Send(HttpRequestMessage request, CancellationToken cancellationToken) at System.Net.Http.HttpClient.Send(HttpRequestMessage request, HttpCompletionOption completionOption, CancellationToken cancellationToken) at NzbDrone.Common.Http.Dispatchers.ManagedHttpDispatcher.GetResponse(HttpRequest request, CookieContainer cookies) in D:\a\1\s\src\NzbDrone.Common\Http\Dispatchers\ManagedHttpDispatcher.cs:line 101 at NzbDrone.Common.Http.HttpClient.ExecuteRequest(HttpRequest request, CookieContainer cookieContainer) in D:\a\1\s\src\NzbDrone.Common\Http\HttpClient.cs:line 124 at NzbDrone.Common.Http.HttpClient.Execute(HttpRequest request) in D:\a\1\s\src\NzbDrone.Common\Http\HttpClient.cs:line 59 at NzbDrone.Core.Indexers.HttpIndexerBase`1.FetchIndexerResponse(IndexerRequest request) in D:\a\1\s\src\NzbDrone.Core\Indexers\HttpIndexerBase.cs:line 309 at NzbDrone.Core.Indexers.HttpIndexerBase`1.FetchPage(IndexerRequest request, IParseIndexerResponse parser) in D:\a\1\s\src\NzbDrone.Core\Indexers\HttpIndexerBase.cs:line 282 at NzbDrone.Core.Indexers.HttpIndexerBase`1.FetchReleases(Func`2 pageableRequestChainSelector, Boolean isRecent) in D:\a\1\s\src\NzbDrone.Core\Indexers\HttpIndexerBase.cs:line 123 FeedUrl: https://www.tabula-rasa.pw/api?t=movie&cat=2000,2010,2020,2030,2035,2040,2045,2050,2060&extended=1&apikey=(removed)&offset=0&limit=100&imdbid=0092099blackhole-diagnostics-20221230-2202blackhole-diagnostics-20221230-2202blackhole-diagnostics-20221230-2202