| | | 1 | | using Microsoft.Extensions.Hosting; |
| | | 2 | | using Microsoft.Extensions.Logging; |
| | | 3 | | using Microsoft.Extensions.Options; |
| | | 4 | | using System.Text; |
| | | 5 | | |
| | | 6 | | namespace AsyncResponse.Transports.RabbitMQ; |
| | | 7 | | |
| | | 8 | | internal abstract class RabbitMqSubscriberService : BackgroundService |
| | | 9 | | { |
| | | 10 | | private readonly IRabbitMqConnectionFactory _connectionFactory; |
| | | 11 | | |
| | | 12 | | /// <summary>Runs the RabbitMqSubscriberService operation.</summary> |
| | | 13 | | protected RabbitMqSubscriberService( |
| | | 14 | | IOptions<RabbitMqAsyncResponseOptions> options, |
| | | 15 | | ILogger logger) |
| | | 16 | | : this(options, logger, new RabbitMqConnectionFactoryAdapter(options.Value)) |
| | | 17 | | { |
| | | 18 | | } |
| | | 19 | | |
| | | 20 | | /// <summary>Runs the RabbitMqSubscriberService operation.</summary> |
| | | 21 | | protected RabbitMqSubscriberService( |
| | | 22 | | IOptions<RabbitMqAsyncResponseOptions> options, |
| | | 23 | | ILogger logger, |
| | | 24 | | IRabbitMqConnectionFactory connectionFactory) |
| | | 25 | | { |
| | | 26 | | Options = options.Value; |
| | | 27 | | Logger = logger; |
| | | 28 | | _connectionFactory = connectionFactory; |
| | | 29 | | } |
| | | 30 | | |
| | | 31 | | protected RabbitMqAsyncResponseOptions Options { get; } |
| | | 32 | | protected ILogger Logger { get; } |
| | | 33 | | |
| | | 34 | | protected abstract string QueueName { get; } |
| | | 35 | | protected abstract RabbitMqSubscriberOptions SubscriberOptions { get; } |
| | | 36 | | protected abstract RabbitMqSubscriberRole SubscriberRole { get; } |
| | | 37 | | /// <summary>Ensures the required resource exists.</summary> |
| | | 38 | | protected abstract Task EnsureTopologyAsync(IRabbitMqChannel channel, CancellationToken cancellationToken); |
| | | 39 | | /// <summary>Handles the delivered message.</summary> |
| | | 40 | | protected abstract Task HandleMessageAsync(RabbitMqDelivery delivery, CancellationToken cancellationToken); |
| | | 41 | | |
| | | 42 | | /// <summary>Runs this background operation until cancellation is requested.</summary> |
| | | 43 | | /// <summary> |
| | | 44 | | /// Validates subscriber options here rather than at the top of <c>ExecuteAsync</c>: since |
| | | 45 | | /// Microsoft.Extensions.Hosting.Abstractions 10.0.10, <c>BackgroundService.StartAsync</c> no |
| | | 46 | | /// longer runs <c>ExecuteAsync</c> inline, so a throw there surfaces only through the host's |
| | | 47 | | /// background-exception handling — or never, when a fast stop discards the queued work — |
| | | 48 | | /// instead of failing host startup synchronously. |
| | | 49 | | /// </summary> |
| | | 50 | | public override Task StartAsync(CancellationToken cancellationToken) |
| | | 51 | | { |
| | | 52 | | _ = QueueName; // Resolving the name enforces its Required check at startup too. |
| | | 53 | | RabbitMqMessageDispatcher.ValidateOptions(Options, SubscriberOptions, SubscriberRole); |
| | | 54 | | return base.StartAsync(cancellationToken); |
| | | 55 | | } |
| | | 56 | | |
| | | 57 | | protected override Task ExecuteAsync(CancellationToken stoppingToken) |
| | | 58 | | { |
| | | 59 | | var queue = QueueName; |
| | | 60 | | |
| | | 61 | | // basic.nack requeue does not increment the x-death header, so the resolved attempt for a plain |
| | | 62 | | // requeued delivery never exceeds 2. Warn once at startup instead of silently never enforcing the cap. |
| | | 63 | | if (SubscriberOptions.AckMode is RabbitMqAckMode.AckAfterHandlerCompletes |
| | | 64 | | && SubscriberOptions.MaxDeliveryAttempts > 2) |
| | | 65 | | { |
| | | 66 | | Logger.LogWarning( |
| | | 67 | | "RabbitMQ {OptionName} is {MaxDeliveryAttempts} for queue {Queue} ({Role}), but attempts beyond 2 cannot |
| | | 68 | | + "basic.nack requeue does not increment x-death, so the cap only takes effect once a TTL-retry dead-let |
| | | 69 | | + "re-delivers the message through a dead-letter exchange. Until then the effective cap is 2 — a failing |
| | | 70 | | + "rejected on its second delivery rather than requeued without limit.", |
| | | 71 | | nameof(RabbitMqSubscriberOptions.MaxDeliveryAttempts), |
| | | 72 | | SubscriberOptions.MaxDeliveryAttempts, |
| | | 73 | | queue, |
| | | 74 | | SubscriberRole); |
| | | 75 | | } |
| | | 76 | | |
| | | 77 | | return SubscriberSupervisor.RunAsync( |
| | | 78 | | ct => RunSubscriberAsync(queue, ct), |
| | | 79 | | stoppingToken, |
| | | 80 | | // Covers failed startup and a mid-run consumer/channel termination alike. Jittered |
| | | 81 | | // backoff, not NetworkRecoveryInterval (which paces the CLIENT's automatic recovery |
| | | 82 | | // of an existing connection): a broker restart drops every consumer on every |
| | | 83 | | // replica at once, and a flat shared delay reconnects them all on the same tick. |
| | | 84 | | failures => AsyncResponseRetry.Backoff(failures, Options.SubscriberRetryBaseDelay, Options.SubscriberRetryMa |
| | | 85 | | (ex, retryDelay) => Logger.LogWarning( |
| | | 86 | | ex, |
| | | 87 | | "RabbitMQ subscriber failed for queue {Queue} ({Role}); retrying in {RetryDelay}.", |
| | | 88 | | queue, |
| | | 89 | | SubscriberRole, |
| | | 90 | | retryDelay)); |
| | | 91 | | } |
| | | 92 | | |
| | | 93 | | private async Task RunSubscriberAsync(string queue, CancellationToken stoppingToken) |
| | | 94 | | { |
| | | 95 | | await using var connection = await _connectionFactory.CreateConnectionAsync(stoppingToken).ConfigureAwait(false) |
| | | 96 | | // Publisher confirmations when a dead-letter exchange is configured: the already-ACKed |
| | | 97 | | // dead-letter copy is published on THIS channel, and without confirmation tracking an |
| | | 98 | | // unroutable (mandatory) return raises only an unobserved basic.return — the publish |
| | | 99 | | // "succeeded" and a successful burial was logged for a message the broker discarded. |
| | | 100 | | // With confirms the publish throws, and the existing catch logs the failure honestly. |
| | | 101 | | // Acks/nacks are unaffected by confirm mode, so channels that never publish pay nothing. |
| | | 102 | | await using var channel = await connection.CreateChannelAsync( |
| | | 103 | | publisherConfirmations: !string.IsNullOrWhiteSpace(Options.DeadLetterExchange), |
| | | 104 | | cancellationToken: stoppingToken).ConfigureAwait(false); |
| | | 105 | | await EnsureTopologyAsync(channel, stoppingToken).ConfigureAwait(false); |
| | | 106 | | await channel.BasicQosAsync(SubscriberOptions.PrefetchCount, stoppingToken).ConfigureAwait(false); |
| | | 107 | | |
| | | 108 | | await using var dispatcher = RabbitMqMessageDispatcher.Create( |
| | | 109 | | HandleMessageAsync, |
| | | 110 | | Options, |
| | | 111 | | SubscriberOptions, |
| | | 112 | | Logger, |
| | | 113 | | queue, |
| | | 114 | | SubscriberRole); |
| | | 115 | | |
| | | 116 | | Logger.LogInformation( |
| | | 117 | | "RabbitMQ subscriber started. Queue: {Queue}. Role: {Role}. AckMode: {AckMode}.", |
| | | 118 | | queue, |
| | | 119 | | SubscriberRole, |
| | | 120 | | SubscriberOptions.AckMode); |
| | | 121 | | |
| | | 122 | | var consumer = await channel.BasicConsumeAsync( |
| | | 123 | | queue, |
| | | 124 | | delivery => dispatcher.HandleAsync(delivery, channel, stoppingToken), |
| | | 125 | | stoppingToken).ConfigureAwait(false); |
| | | 126 | | |
| | | 127 | | // Park until host shutdown or consumer termination. The termination task is the only signal |
| | | 128 | | // that deliveries stopped (broker-side basic.cancel and channel-level closes raise no |
| | | 129 | | // exception here), so parking on the stopping token alone would keep a dead subscription |
| | | 130 | | // alive forever. A registration-fed TCS instead of an infinite Task.Delay: a faulted |
| | | 131 | | // iteration must not leak one timer + token registration per rebuild. |
| | | 132 | | var stopped = new TaskCompletionSource(TaskCreationOptions.RunContinuationsAsynchronously); |
| | | 133 | | using (stoppingToken.Register(() => stopped.TrySetResult())) |
| | | 134 | | { |
| | | 135 | | var first = await Task.WhenAny(consumer.Terminated, stopped.Task).ConfigureAwait(false); |
| | | 136 | | |
| | | 137 | | // A client-initiated cancel during shutdown also completes Terminated (cancel-ok raises |
| | | 138 | | // UnregisteredAsync), so termination is a failure only while the host is still running. |
| | | 139 | | // Throwing hands control to the ExecuteAsync retry loop, which disposes this |
| | | 140 | | // connection/channel (via await using) and rebuilds both plus the consumer after backoff. |
| | | 141 | | if (first == consumer.Terminated && !stoppingToken.IsCancellationRequested) |
| | | 142 | | { |
| | | 143 | | var reason = await consumer.Terminated.ConfigureAwait(false); |
| | | 144 | | throw new InvalidOperationException( |
| | | 145 | | $"RabbitMQ consumer for queue '{queue}' ({SubscriberRole}) stopped receiving: {reason}."); |
| | | 146 | | } |
| | | 147 | | } |
| | | 148 | | |
| | | 149 | | using var shutdown = new CancellationTokenSource(Options.ShutdownTimeout); |
| | | 150 | | await channel.BasicCancelAsync(consumer.ConsumerTag, shutdown.Token).ConfigureAwait(false); |
| | | 151 | | |
| | | 152 | | // Drain the ACK-after-enqueue background queue BEFORE closing the channel and connection |
| | | 153 | | // (Kafka parity: "leaving the await-using scope drains ... before the consumer commits"). |
| | | 154 | | // The drain's dead-letter publishes ride this consumer channel, so closing it first made |
| | | 155 | | // TryDeadLetterAlreadyAckedAsync find the channel closed on every graceful shutdown and |
| | | 156 | | // each already-ACKed failure during the drain lost its DLX record. DisposeAsync is |
| | | 157 | | // idempotent, so the `await using` unwind after the closes is a no-op. |
| | | 158 | | await dispatcher.DisposeAsync().ConfigureAwait(false); |
| | | 159 | | |
| | | 160 | | // A fresh budget for the closes (ASB/SQS parity: arm the source right before the call it |
| | | 161 | | // bounds). The drain above can run up to BackgroundDrainTimeout, longer than the 5 s |
| | | 162 | | // ShutdownTimeout, so the token armed for BasicCancel was already cancelled by the time |
| | | 163 | | // it reached CloseAsync — which threw, skipped the connection close, and left both to |
| | | 164 | | // the unbounded await-using unwind on every early-ACK shutdown. |
| | | 165 | | using var closeBudget = new CancellationTokenSource(Options.ShutdownTimeout); |
| | | 166 | | await channel.CloseAsync(closeBudget.Token).ConfigureAwait(false); |
| | | 167 | | await connection.CloseAsync(Options.ShutdownTimeout, closeBudget.Token).ConfigureAwait(false); |
| | | 168 | | } |
| | | 169 | | } |
| | | 170 | | |
| | | 171 | | internal sealed class RabbitMqWorkerSubscriber : RabbitMqSubscriberService |
| | | 172 | | { |
| | | 173 | | private readonly IAsyncResponseIngress _ingress; |
| | | 174 | | |
| | | 175 | | /// <summary>Runs the RabbitMqWorkerSubscriber operation.</summary> |
| | | 176 | | public RabbitMqWorkerSubscriber( |
| | | 177 | | IOptions<RabbitMqAsyncResponseOptions> options, |
| | | 178 | | IAsyncResponseIngress ingress, |
| | | 179 | | ILogger<RabbitMqWorkerSubscriber> logger) |
| | | 180 | | : base(options, logger) |
| | | 181 | | { |
| | | 182 | | _ingress = ingress; |
| | | 183 | | } |
| | | 184 | | |
| | | 185 | | internal RabbitMqWorkerSubscriber( |
| | | 186 | | IOptions<RabbitMqAsyncResponseOptions> options, |
| | | 187 | | IAsyncResponseIngress ingress, |
| | | 188 | | ILogger<RabbitMqWorkerSubscriber> logger, |
| | | 189 | | IRabbitMqConnectionFactory connectionFactory) |
| | | 190 | | : base(options, logger, connectionFactory) |
| | | 191 | | { |
| | | 192 | | _ingress = ingress; |
| | | 193 | | } |
| | | 194 | | |
| | | 195 | | protected override string QueueName |
| | | 196 | | => RabbitMqOptionsValidator.Required(Options.WorkerQueue, nameof(Options.WorkerQueue)); |
| | | 197 | | |
| | | 198 | | protected override RabbitMqSubscriberOptions SubscriberOptions => Options.WorkerSubscriber; |
| | | 199 | | protected override RabbitMqSubscriberRole SubscriberRole => RabbitMqSubscriberRole.Worker; |
| | | 200 | | |
| | | 201 | | /// <summary>Ensures the required resource exists.</summary> |
| | | 202 | | protected override Task EnsureTopologyAsync(IRabbitMqChannel channel, CancellationToken cancellationToken) |
| | | 203 | | => RabbitMqTopology.EnsureWorkerAsync(channel, Options, cancellationToken); |
| | | 204 | | |
| | | 205 | | /// <summary>Handles the delivered message.</summary> |
| | | 206 | | protected override Task HandleMessageAsync(RabbitMqDelivery delivery, CancellationToken cancellationToken) |
| | | 207 | | => _ingress.HandleWorkerMessageAsync(Encoding.UTF8.GetString(delivery.Body.Span)); |
| | | 208 | | } |
| | | 209 | | |
| | | 210 | | internal sealed class RabbitMqResponseIngressSubscriber : RabbitMqSubscriberService |
| | | 211 | | { |
| | | 212 | | private readonly IAsyncResponseIngress _ingress; |
| | | 213 | | |
| | | 214 | | /// <summary>Runs the RabbitMqResponseIngressSubscriber operation.</summary> |
| | | 215 | | public RabbitMqResponseIngressSubscriber( |
| | | 216 | | IOptions<RabbitMqAsyncResponseOptions> options, |
| | | 217 | | IAsyncResponseIngress ingress, |
| | | 218 | | ILogger<RabbitMqResponseIngressSubscriber> logger) |
| | 196 | 219 | | : base(options, logger) |
| | | 220 | | { |
| | 196 | 221 | | _ingress = ingress; |
| | 196 | 222 | | } |
| | | 223 | | |
| | | 224 | | internal RabbitMqResponseIngressSubscriber( |
| | | 225 | | IOptions<RabbitMqAsyncResponseOptions> options, |
| | | 226 | | IAsyncResponseIngress ingress, |
| | | 227 | | ILogger<RabbitMqResponseIngressSubscriber> logger, |
| | | 228 | | IRabbitMqConnectionFactory connectionFactory) |
| | 4 | 229 | | : base(options, logger, connectionFactory) |
| | | 230 | | { |
| | 4 | 231 | | _ingress = ingress; |
| | 4 | 232 | | } |
| | | 233 | | |
| | | 234 | | protected override string QueueName |
| | 390 | 235 | | => RabbitMqOptionsValidator.Required(Options.ResponseQueue, nameof(Options.ResponseQueue)); |
| | | 236 | | |
| | 1164 | 237 | | protected override RabbitMqSubscriberOptions SubscriberOptions => Options.ResponseSubscriber; |
| | 589 | 238 | | protected override RabbitMqSubscriberRole SubscriberRole => RabbitMqSubscriberRole.ResponseIngress; |
| | | 239 | | |
| | | 240 | | /// <summary>Ensures the required resource exists.</summary> |
| | | 241 | | protected override Task EnsureTopologyAsync(IRabbitMqChannel channel, CancellationToken cancellationToken) |
| | 194 | 242 | | => RabbitMqTopology.EnsureResponseAsync(channel, Options, cancellationToken); |
| | | 243 | | |
| | | 244 | | /// <summary>Handles the delivered message.</summary> |
| | | 245 | | protected override Task HandleMessageAsync(RabbitMqDelivery delivery, CancellationToken cancellationToken) |
| | | 246 | | { |
| | 2 | 247 | | var messageJson = Encoding.UTF8.GetString(delivery.Body.Span); |
| | 2 | 248 | | var correlationId = !_ingress.IsOverInboundBudget(messageJson) |
| | 2 | 249 | | ? RabbitMqCorrelationIdExtractor.Extract(delivery, messageJson, Options) |
| | 2 | 250 | | : null; |
| | 2 | 251 | | return _ingress.HandleResponseMessageAsync(messageJson, correlationId); |
| | | 252 | | } |
| | | 253 | | } |