| | | 1 | | using Microsoft.Extensions.Hosting; |
| | | 2 | | using Microsoft.Extensions.Logging; |
| | | 3 | | using Microsoft.Extensions.Options; |
| | | 4 | | |
| | | 5 | | namespace AsyncResponse.Transports.AzureServiceBus; |
| | | 6 | | |
| | | 7 | | internal abstract class AzureServiceBusSubscriberService : BackgroundService |
| | | 8 | | { |
| | | 9 | | private readonly IAzureServiceBusClient _client; |
| | | 10 | | |
| | | 11 | | protected AzureServiceBusSubscriberService( |
| | | 12 | | IOptions<AzureServiceBusAsyncResponseOptions> options, |
| | | 13 | | IAzureServiceBusClient client, |
| | | 14 | | ILogger logger) |
| | | 15 | | { |
| | | 16 | | Options = options.Value; |
| | | 17 | | AzureServiceBusOptionsValidator.ValidateCommon(Options); |
| | | 18 | | _client = client; |
| | | 19 | | Logger = logger; |
| | | 20 | | } |
| | | 21 | | |
| | | 22 | | protected AzureServiceBusAsyncResponseOptions Options { get; } |
| | | 23 | | protected ILogger Logger { get; } |
| | | 24 | | |
| | | 25 | | protected abstract string QueueName { get; } |
| | | 26 | | protected abstract AzureServiceBusSubscriberOptions SubscriberOptions { get; } |
| | | 27 | | protected abstract AzureServiceBusSubscriberRole SubscriberRole { get; } |
| | | 28 | | /// <summary>Handles the delivered message.</summary> |
| | | 29 | | protected abstract Task HandleMessageAsync(AzureServiceBusTransportDelivery delivery, CancellationToken cancellation |
| | | 30 | | |
| | | 31 | | /// <summary>Runs this background operation until cancellation is requested.</summary> |
| | | 32 | | /// <summary> |
| | | 33 | | /// Validates subscriber options here rather than at the top of <c>ExecuteAsync</c>: since |
| | | 34 | | /// Microsoft.Extensions.Hosting.Abstractions 10.0.10, <c>BackgroundService.StartAsync</c> no |
| | | 35 | | /// longer runs <c>ExecuteAsync</c> inline, so a throw there surfaces only through the host's |
| | | 36 | | /// background-exception handling — or never, when a fast stop discards the queued work — |
| | | 37 | | /// instead of failing host startup synchronously. |
| | | 38 | | /// </summary> |
| | | 39 | | public override Task StartAsync(CancellationToken cancellationToken) |
| | | 40 | | { |
| | | 41 | | _ = QueueName; // Resolving the name enforces its Required check at startup too. |
| | | 42 | | AzureServiceBusMessageDispatcher.ValidateOptions(Options, SubscriberOptions, SubscriberRole); |
| | | 43 | | return base.StartAsync(cancellationToken); |
| | | 44 | | } |
| | | 45 | | |
| | | 46 | | protected override Task ExecuteAsync(CancellationToken stoppingToken) |
| | | 47 | | { |
| | | 48 | | var queue = QueueName; |
| | | 49 | | return SubscriberSupervisor.RunAsync( |
| | | 50 | | ct => RunSubscriberAsync(queue, ct), |
| | | 51 | | stoppingToken, |
| | | 52 | | failures => AsyncResponseRetry.Backoff(failures, Options.SubscriberRetryBaseDelay, Options.SubscriberRetryMa |
| | | 53 | | (ex, retryDelay) => Logger.LogWarning( |
| | | 54 | | ex, |
| | | 55 | | "Azure Service Bus subscriber failed for queue {Queue} ({Role}); retrying in {RetryDelay}.", |
| | | 56 | | queue, |
| | | 57 | | SubscriberRole, |
| | | 58 | | retryDelay)); |
| | | 59 | | } |
| | | 60 | | |
| | | 61 | | private async Task RunSubscriberAsync(string queue, CancellationToken stoppingToken) |
| | | 62 | | { |
| | | 63 | | await using var receiver = _client.CreateReceiver(queue, SubscriberOptions); |
| | | 64 | | await using var dispatcher = AzureServiceBusMessageDispatcher.Create( |
| | | 65 | | HandleMessageAsync, |
| | | 66 | | Options, |
| | | 67 | | SubscriberOptions, |
| | | 68 | | Logger, |
| | | 69 | | queue, |
| | | 70 | | SubscriberRole); |
| | | 71 | | |
| | | 72 | | Logger.LogInformation( |
| | | 73 | | "Azure Service Bus subscriber started. Queue: {Queue}. Role: {Role}. AckMode: {AckMode}.", |
| | | 74 | | queue, |
| | | 75 | | SubscriberRole, |
| | | 76 | | SubscriberOptions.AckMode); |
| | | 77 | | |
| | | 78 | | try |
| | | 79 | | { |
| | | 80 | | while (!stoppingToken.IsCancellationRequested) |
| | | 81 | | { |
| | | 82 | | // In early-ACK mode, receiving while the background queue is saturated would burn |
| | | 83 | | // DeliveryCount via queue-full abandons, so wait for free capacity and never request |
| | | 84 | | // more messages than the dispatcher can accept. |
| | | 85 | | await dispatcher.WaitForCapacityAsync(stoppingToken).ConfigureAwait(false); |
| | | 86 | | var maxMessages = Math.Min(Options.MaxMessagesPerReceive, dispatcher.FreeCapacity); |
| | | 87 | | |
| | | 88 | | var messages = await receiver.ReceiveMessagesAsync( |
| | | 89 | | maxMessages, |
| | | 90 | | Options.ReceiveWaitTime, |
| | | 91 | | stoppingToken).ConfigureAwait(false); |
| | | 92 | | |
| | | 93 | | await DispatchBatchAsync(dispatcher, messages, queue, stoppingToken).ConfigureAwait(false); |
| | | 94 | | } |
| | | 95 | | } |
| | | 96 | | catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested) |
| | | 97 | | { |
| | | 98 | | using var shutdown = new CancellationTokenSource(Options.ShutdownTimeout); |
| | | 99 | | await receiver.CloseAsync(shutdown.Token).ConfigureAwait(false); |
| | | 100 | | } |
| | | 101 | | } |
| | | 102 | | |
| | | 103 | | private async Task DispatchBatchAsync( |
| | | 104 | | AzureServiceBusMessageDispatcher dispatcher, |
| | | 105 | | IReadOnlyList<AzureServiceBusTransportDelivery> messages, |
| | | 106 | | string queue, |
| | | 107 | | CancellationToken stoppingToken) |
| | | 108 | | { |
| | | 109 | | if (messages.Count == 0) |
| | | 110 | | return; |
| | | 111 | | |
| | | 112 | | if (SubscriberOptions.AckMode is not AzureServiceBusAckMode.AckAfterHandlerCompletes |
| | | 113 | | || SubscriberOptions.LockRenewalInterval is not { } renewalInterval) |
| | | 114 | | { |
| | | 115 | | foreach (var message in messages) |
| | | 116 | | await dispatcher.HandleAsync(message, stoppingToken).ConfigureAwait(false); |
| | | 117 | | return; |
| | | 118 | | } |
| | | 119 | | |
| | | 120 | | // The batch is processed serially, so a slow handler lets the peek locks of the later (still |
| | | 121 | | // unsettled) messages expire and Service Bus redelivers them to a competing consumer while |
| | | 122 | | // they are still queued here — systematic duplicate processing. While the batch is in flight, |
| | | 123 | | // a background loop renews the lock of every unsettled message each interval. |
| | | 124 | | var progress = new BatchProgress(); |
| | | 125 | | using var renewalCancellation = CancellationTokenSource.CreateLinkedTokenSource(stoppingToken); |
| | | 126 | | var renewalTask = RenewLocksLoopAsync(messages, progress, renewalInterval, queue, renewalCancellation.Token); |
| | | 127 | | try |
| | | 128 | | { |
| | | 129 | | foreach (var message in messages) |
| | | 130 | | { |
| | | 131 | | try |
| | | 132 | | { |
| | | 133 | | await dispatcher.HandleAsync(message, stoppingToken).ConfigureAwait(false); |
| | | 134 | | } |
| | | 135 | | finally |
| | | 136 | | { |
| | | 137 | | progress.MarkSettled(); |
| | | 138 | | } |
| | | 139 | | } |
| | | 140 | | } |
| | | 141 | | finally |
| | | 142 | | { |
| | | 143 | | renewalCancellation.Cancel(); |
| | | 144 | | try |
| | | 145 | | { |
| | | 146 | | // Cancellation exits the sweep between messages and interrupts the in-flight renew |
| | | 147 | | // call, so this normally completes immediately. The bound is the hard backstop: an |
| | | 148 | | // unbounded await here would let a degraded namespace hold the receive loop (and, at |
| | | 149 | | // shutdown, the whole host budget) hostage for the SDK retry budget per message. |
| | | 150 | | await renewalTask.WaitAsync(Options.ShutdownTimeout).ConfigureAwait(false); |
| | | 151 | | } |
| | | 152 | | catch (TimeoutException) |
| | | 153 | | { |
| | | 154 | | Logger.LogWarning( |
| | | 155 | | "Azure Service Bus lock renewal for {Queue} ({Role}) did not stop within the shutdown budget ({Shutd |
| | | 156 | | queue, |
| | | 157 | | SubscriberRole, |
| | | 158 | | Options.ShutdownTimeout); |
| | | 159 | | } |
| | | 160 | | } |
| | | 161 | | } |
| | | 162 | | |
| | | 163 | | private async Task RenewLocksLoopAsync( |
| | | 164 | | IReadOnlyList<AzureServiceBusTransportDelivery> messages, |
| | | 165 | | BatchProgress progress, |
| | | 166 | | TimeSpan renewalInterval, |
| | | 167 | | string queue, |
| | | 168 | | CancellationToken cancellationToken) |
| | | 169 | | { |
| | | 170 | | try |
| | | 171 | | { |
| | | 172 | | while (true) |
| | | 173 | | { |
| | | 174 | | await Task.Delay(renewalInterval, cancellationToken).ConfigureAwait(false); |
| | | 175 | | |
| | | 176 | | // Renew from the first unsettled message onward: that covers the message currently in |
| | | 177 | | // the handler plus everything still waiting its turn. A renewal racing a just-settled |
| | | 178 | | // message merely fails and is logged; redelivery keeps at-least-once intact. |
| | | 179 | | for (var i = progress.SettledCount; i < messages.Count; i++) |
| | | 180 | | { |
| | | 181 | | // The batch finished or the subscriber is stopping: exit quietly between messages |
| | | 182 | | // instead of spending up to a full SDK retry budget on each remaining renew. |
| | | 183 | | if (cancellationToken.IsCancellationRequested) |
| | | 184 | | return; |
| | | 185 | | |
| | | 186 | | var message = messages[i]; |
| | | 187 | | try |
| | | 188 | | { |
| | | 189 | | await message.RenewLockAsync(cancellationToken).ConfigureAwait(false); |
| | | 190 | | } |
| | | 191 | | catch (OperationCanceledException) when (cancellationToken.IsCancellationRequested) |
| | | 192 | | { |
| | | 193 | | // Our token interrupted the in-flight renew; not a renewal failure. |
| | | 194 | | return; |
| | | 195 | | } |
| | | 196 | | catch (Exception ex) |
| | | 197 | | { |
| | | 198 | | Logger.LogWarning( |
| | | 199 | | ex, |
| | | 200 | | "Failed to renew the lock of Azure Service Bus message {MessageId} on {Queue}; it may redeli |
| | | 201 | | message.MessageId, |
| | | 202 | | queue); |
| | | 203 | | } |
| | | 204 | | } |
| | | 205 | | } |
| | | 206 | | } |
| | | 207 | | catch (OperationCanceledException) |
| | | 208 | | { |
| | | 209 | | // The batch finished or the subscriber is stopping. |
| | | 210 | | } |
| | | 211 | | } |
| | | 212 | | |
| | | 213 | | private sealed class BatchProgress |
| | | 214 | | { |
| | | 215 | | private int _settledCount; |
| | | 216 | | |
| | | 217 | | public int SettledCount => Volatile.Read(ref _settledCount); |
| | | 218 | | |
| | | 219 | | public void MarkSettled() => Interlocked.Increment(ref _settledCount); |
| | | 220 | | } |
| | | 221 | | } |
| | | 222 | | |
| | | 223 | | internal sealed class AzureServiceBusWorkerSubscriber : AzureServiceBusSubscriberService |
| | | 224 | | { |
| | | 225 | | private readonly IAsyncResponseIngress _ingress; |
| | | 226 | | |
| | | 227 | | /// <summary>Creates a worker subscriber for the configured Service Bus worker queue.</summary> |
| | | 228 | | public AzureServiceBusWorkerSubscriber( |
| | | 229 | | IOptions<AzureServiceBusAsyncResponseOptions> options, |
| | | 230 | | IAzureServiceBusClient client, |
| | | 231 | | IAsyncResponseIngress ingress, |
| | | 232 | | ILogger<AzureServiceBusWorkerSubscriber> logger) |
| | | 233 | | : base(options, client, logger) |
| | | 234 | | { |
| | | 235 | | _ingress = ingress; |
| | | 236 | | } |
| | | 237 | | |
| | | 238 | | protected override string QueueName |
| | | 239 | | => AzureServiceBusOptionsValidator.Required(Options.WorkerQueue, nameof(Options.WorkerQueue)); |
| | | 240 | | |
| | | 241 | | protected override AzureServiceBusSubscriberOptions SubscriberOptions => Options.WorkerSubscriber; |
| | | 242 | | protected override AzureServiceBusSubscriberRole SubscriberRole => AzureServiceBusSubscriberRole.Worker; |
| | | 243 | | |
| | | 244 | | /// <summary>Handles the delivered message.</summary> |
| | | 245 | | protected override Task HandleMessageAsync(AzureServiceBusTransportDelivery delivery, CancellationToken cancellation |
| | | 246 | | => _ingress.HandleWorkerMessageAsync(delivery.Body); |
| | | 247 | | } |
| | | 248 | | |
| | | 249 | | internal sealed class AzureServiceBusResponseIngressSubscriber : AzureServiceBusSubscriberService |
| | | 250 | | { |
| | | 251 | | private readonly IAsyncResponseIngress _ingress; |
| | | 252 | | |
| | | 253 | | /// <summary>Creates a response subscriber for the configured Service Bus response queue.</summary> |
| | | 254 | | public AzureServiceBusResponseIngressSubscriber( |
| | | 255 | | IOptions<AzureServiceBusAsyncResponseOptions> options, |
| | | 256 | | IAzureServiceBusClient client, |
| | | 257 | | IAsyncResponseIngress ingress, |
| | | 258 | | ILogger<AzureServiceBusResponseIngressSubscriber> logger) |
| | 198 | 259 | | : base(options, client, logger) |
| | | 260 | | { |
| | 198 | 261 | | _ingress = ingress; |
| | 198 | 262 | | } |
| | | 263 | | |
| | | 264 | | protected override string QueueName |
| | 388 | 265 | | => AzureServiceBusOptionsValidator.Required(Options.ResponseQueue, nameof(Options.ResponseQueue)); |
| | | 266 | | |
| | 780 | 267 | | protected override AzureServiceBusSubscriberOptions SubscriberOptions => Options.ResponseSubscriber; |
| | 582 | 268 | | protected override AzureServiceBusSubscriberRole SubscriberRole => AzureServiceBusSubscriberRole.ResponseIngress; |
| | | 269 | | |
| | | 270 | | /// <summary>Handles the delivered message.</summary> |
| | | 271 | | protected override Task HandleMessageAsync(AzureServiceBusTransportDelivery delivery, CancellationToken cancellation |
| | | 272 | | { |
| | 2 | 273 | | var correlationId = !_ingress.IsOverInboundBudget(delivery.Body) |
| | 2 | 274 | | ? AzureServiceBusCorrelationIdExtractor.Extract(delivery, delivery.Body, Options) |
| | 2 | 275 | | : null; |
| | 2 | 276 | | return _ingress.HandleResponseMessageAsync(delivery.Body, correlationId); |
| | | 277 | | } |
| | | 278 | | } |