Fixed: (Rarbg) Improve RateLimit Handling

Fixed: (Rarbg) Increase delay to 4s to reduce Rate Limiting

Fixes #1169

src/NzbDrone.Core/Indexers/Definitions/Rarbg/Rarbg.cs

@@ -34,7 +34,7 @@ namespace NzbDrone.Core.Indexers.Rarbg
 
         public override IndexerCapabilities Capabilities => SetCapabilities();
 
-        public override TimeSpan RateLimit => TimeSpan.FromSeconds(2);
+        public override TimeSpan RateLimit => TimeSpan.FromSeconds(4);
 
         public Rarbg(IRarbgTokenProvider tokenProvider, IIndexerHttpClient httpClient, IEventAggregator eventAggregator, IIndexerStatusService indexerStatusService, IConfigService configService, Logger logger)
             : base(httpClient, eventAggregator, indexerStatusService, configService, logger)
@@ -106,7 +106,8 @@ namespace NzbDrone.Core.Indexers.Rarbg
         {
             var response = await FetchIndexerResponse(request);
 
-            // try and recover from token or rate limit errors
+            // try and recover from token errors
+            // Response of 200 and rate_limt of 1 requires a 5 minute backoff. Handle in Response Parsing & do not page further if rate_limit is populated.
             var jsonResponse = new HttpResponse<RarbgResponse>(response.HttpResponse);
 
             if (jsonResponse.Resource.error_code.HasValue)
@@ -123,9 +124,9 @@ namespace NzbDrone.Core.Indexers.Rarbg
                     request.HttpRequest.Url = request.Url.SetQuery(qs.GetQueryString());
                     response = await FetchIndexerResponse(request);
                 }
-                else if (jsonResponse.Resource.error_code == 5 || jsonResponse.Resource.rate_limit.HasValue)
+                else if (jsonResponse.Resource.error_code == 5)
                 {
-                    _logger.Debug("Rarbg rate limit hit, retying request");
+                    _logger.Debug("Rarbg temp rate limit hit, retying request");
                     response = await FetchIndexerResponse(request);
                 }
             }

src/NzbDrone.Core/Indexers/Definitions/Rarbg/RarbgParser.cs

@@ -23,20 +23,32 @@ namespace NzbDrone.Core.Indexers.Rarbg
         public IList<ReleaseInfo> ParseResponse(IndexerResponse indexerResponse)
         {
             var results = new List<ReleaseInfo>();
+            var retryTime = TimeSpan.FromMinutes(1);
+            var responseCode = (int)indexerResponse.HttpResponse.StatusCode;
 
-            switch (indexerResponse.HttpResponse.StatusCode)
+            switch (responseCode)
             {
-                default:
-                    if (indexerResponse.HttpResponse.StatusCode != HttpStatusCode.OK)
-                    {
-                        throw new IndexerException(indexerResponse, "Indexer API call returned an unexpected StatusCode [{0}]", indexerResponse.HttpResponse.StatusCode);
-                    }
-
+                case (int)HttpStatusCode.TooManyRequests:
+                    retryTime = TimeSpan.FromMinutes(2);
+                    throw new TooManyRequestsException(indexerResponse.HttpRequest, indexerResponse.HttpResponse, retryTime);
+                case 520:
+                    retryTime = TimeSpan.FromMinutes(3);
+                    throw new TooManyRequestsException(indexerResponse.HttpRequest, indexerResponse.HttpResponse, retryTime);
+                case (int)HttpStatusCode.OK:
+                    retryTime = TimeSpan.FromMinutes(5);
                     break;
+                default:
+                    throw new IndexerException(indexerResponse, "Indexer API call returned an unexpected StatusCode [{0}]", responseCode);
             }
 
             var jsonResponse = new HttpResponse<RarbgResponse>(indexerResponse.HttpResponse);
 
+            // Handle 200 Rate Limiting
+            if (jsonResponse.Resource.rate_limit == 1)
+            {
+                throw new TooManyRequestsException(indexerResponse.HttpRequest, indexerResponse.HttpResponse, retryTime);
+            }
+
             if (jsonResponse.Resource.error_code.HasValue)
             {
                 if (jsonResponse.Resource.error_code == 20 || jsonResponse.Resource.error_code == 8