| | | 1 | | using Microsoft.Extensions.Logging; |
| | | 2 | | using StackExchange.Redis; |
| | | 3 | | using System.Diagnostics; |
| | | 4 | | using System.Threading.Channels; |
| | | 5 | | |
| | | 6 | | namespace AsyncResponse.Transports.Redis; |
| | | 7 | | |
| | | 8 | | internal enum RedisSubscriberRole |
| | | 9 | | { |
| | | 10 | | Worker, |
| | | 11 | | ResponseIngress |
| | | 12 | | } |
| | | 13 | | |
| | | 14 | | internal enum RedisDispatchOutcome |
| | | 15 | | { |
| | | 16 | | /// <summary>The entry was handled, ACKed, or dead-lettered. Counts as progress for the poll loop.</summary> |
| | | 17 | | Processed, |
| | | 18 | | |
| | | 19 | | /// <summary>The entry could not be accepted right now (background queue full) and was left pending for retry.</summ |
| | | 20 | | Deferred |
| | | 21 | | } |
| | | 22 | | |
| | 522 | 23 | | internal sealed record RedisStreamDelivery( |
| | 550 | 24 | | RedisKey Stream, |
| | 544 | 25 | | RedisValue ConsumerGroup, |
| | 619 | 26 | | RedisValue MessageId, |
| | 477 | 27 | | string Payload, |
| | 543 | 28 | | string? CorrelationId, |
| | 561 | 29 | | int Attempt, |
| | 522 | 30 | | StreamEntry Entry); |
| | | 31 | | |
| | | 32 | | internal abstract class RedisMessageDispatcher : IAsyncDisposable |
| | | 33 | | { |
| | | 34 | | private readonly Func<RedisStreamDelivery, CancellationToken, Task> _handler; |
| | | 35 | | private readonly RedisSubscriberOptions _subscriberOptions; |
| | | 36 | | private readonly IRedisStreamDatabase _database; |
| | | 37 | | private readonly RedisTransportKeySchema _keys; |
| | | 38 | | private readonly string _stream; |
| | | 39 | | private readonly string _consumerGroup; |
| | | 40 | | private readonly RedisSubscriberRole _role; |
| | | 41 | | |
| | | 42 | | /// <summary>Runs the RedisMessageDispatcher operation.</summary> |
| | | 43 | | protected RedisMessageDispatcher( |
| | | 44 | | Func<RedisStreamDelivery, CancellationToken, Task> handler, |
| | | 45 | | IRedisStreamDatabase database, |
| | | 46 | | RedisAsyncResponseTransportOptions transportOptions, |
| | | 47 | | RedisSubscriberOptions subscriberOptions, |
| | | 48 | | ILogger logger, |
| | | 49 | | RedisKey stream, |
| | | 50 | | RedisValue consumerGroup, |
| | | 51 | | RedisSubscriberRole role) |
| | | 52 | | { |
| | | 53 | | _handler = handler; |
| | | 54 | | _database = database; |
| | | 55 | | TransportOptions = transportOptions; |
| | | 56 | | _subscriberOptions = subscriberOptions; |
| | | 57 | | _keys = new RedisTransportKeySchema(transportOptions); |
| | | 58 | | Logger = logger; |
| | | 59 | | _stream = stream.ToString(); |
| | | 60 | | _consumerGroup = consumerGroup.ToString(); |
| | | 61 | | _role = role; |
| | | 62 | | } |
| | | 63 | | |
| | | 64 | | protected RedisAsyncResponseTransportOptions TransportOptions { get; } |
| | | 65 | | protected ILogger Logger { get; } |
| | | 66 | | |
| | | 67 | | protected int MaxDeliveryAttempts => _subscriberOptions.MaxDeliveryAttempts; |
| | | 68 | | |
| | | 69 | | /// <summary>Creates the configured dispatcher.</summary> |
| | | 70 | | public static RedisMessageDispatcher Create( |
| | | 71 | | Func<RedisStreamDelivery, CancellationToken, Task> handler, |
| | | 72 | | IRedisStreamDatabase database, |
| | | 73 | | RedisAsyncResponseTransportOptions transportOptions, |
| | | 74 | | RedisSubscriberOptions subscriberOptions, |
| | | 75 | | ILogger logger, |
| | | 76 | | RedisKey stream, |
| | | 77 | | RedisValue consumerGroup, |
| | | 78 | | RedisSubscriberRole role) |
| | | 79 | | { |
| | | 80 | | ValidateOptions(transportOptions, subscriberOptions, role); |
| | | 81 | | |
| | | 82 | | if (subscriberOptions.AckMode is RedisAckMode.AckAfterEnqueue) |
| | | 83 | | { |
| | | 84 | | return new QueuedRedisMessageDispatcher( |
| | | 85 | | handler, |
| | | 86 | | database, |
| | | 87 | | transportOptions, |
| | | 88 | | subscriberOptions, |
| | | 89 | | logger, |
| | | 90 | | stream, |
| | | 91 | | consumerGroup, |
| | | 92 | | role); |
| | | 93 | | } |
| | | 94 | | |
| | | 95 | | return new AwaitingRedisMessageDispatcher( |
| | | 96 | | handler, |
| | | 97 | | database, |
| | | 98 | | transportOptions, |
| | | 99 | | subscriberOptions, |
| | | 100 | | logger, |
| | | 101 | | stream, |
| | | 102 | | consumerGroup, |
| | | 103 | | role); |
| | | 104 | | } |
| | | 105 | | |
| | | 106 | | /// <summary>Validates the supplied options.</summary> |
| | | 107 | | public static void ValidateOptions( |
| | | 108 | | RedisAsyncResponseTransportOptions transportOptions, |
| | | 109 | | RedisSubscriberOptions subscriberOptions, |
| | | 110 | | RedisSubscriberRole role) |
| | | 111 | | { |
| | | 112 | | RedisTransportOptionsValidator.ValidateCommon(transportOptions); |
| | | 113 | | |
| | | 114 | | var optionPath = role is RedisSubscriberRole.Worker |
| | | 115 | | ? $"{nameof(RedisAsyncResponseTransportOptions)}.{nameof(RedisAsyncResponseTransportOptions.WorkerSubscriber |
| | | 116 | | : $"{nameof(RedisAsyncResponseTransportOptions)}.{nameof(RedisAsyncResponseTransportOptions.ResponseSubscrib |
| | | 117 | | |
| | | 118 | | if (subscriberOptions.BatchSize <= 0) |
| | | 119 | | throw new InvalidOperationException($"{optionPath}.{nameof(RedisSubscriberOptions.BatchSize)} must be positi |
| | | 120 | | // EmptyPollDelay arms the idle Task.Delay (timer ceiling). PendingMessageMinIdleTime is |
| | | 121 | | // the server-side XAUTOCLAIM min-idle in milliseconds, but it ALSO arms the in-process |
| | | 122 | | // idle-reset heartbeat's Task.Delay at one third of its value, so its real sink is the |
| | | 123 | | // timer ceiling too — under the persistence bound a legal 200-day value passed validation |
| | | 124 | | // and then killed every batch with ArgumentOutOfRangeException from the heartbeat's delay. |
| | | 125 | | // PendingClaimInterval is a "now + interval" schedule stamp and keeps the persistence bound. |
| | | 126 | | AsyncResponseChannelOptions.EnsureTimerBacked(subscriberOptions.EmptyPollDelay, optionPath, nameof(RedisSubscrib |
| | | 127 | | AsyncResponseChannelOptions.EnsureTimerBacked(subscriberOptions.PendingMessageMinIdleTime, optionPath, nameof(Re |
| | | 128 | | AsyncResponseChannelOptions.EnsurePersistedTtl(subscriberOptions.PendingClaimInterval, optionPath, nameof(RedisS |
| | | 129 | | if (subscriberOptions.PendingClaimBatchSize <= 0) |
| | | 130 | | throw new InvalidOperationException($"{optionPath}.{nameof(RedisSubscriberOptions.PendingClaimBatchSize)} mu |
| | | 131 | | if (subscriberOptions.MaxDeliveryAttempts < 0) |
| | | 132 | | throw new InvalidOperationException($"{optionPath}.{nameof(RedisSubscriberOptions.MaxDeliveryAttempts)} cann |
| | | 133 | | |
| | | 134 | | switch (subscriberOptions.AckMode) |
| | | 135 | | { |
| | | 136 | | case RedisAckMode.AckAfterHandlerCompletes: |
| | | 137 | | return; |
| | | 138 | | |
| | | 139 | | case RedisAckMode.AckAfterEnqueue: |
| | | 140 | | if (subscriberOptions.BackgroundWorkerCount <= 0) |
| | | 141 | | { |
| | | 142 | | throw new InvalidOperationException( |
| | | 143 | | $"{optionPath}.{nameof(RedisSubscriberOptions.BackgroundWorkerCount)} must be explicitly configu |
| | | 144 | | $"when {nameof(RedisSubscriberOptions.AckMode)} is {nameof(RedisAckMode.AckAfterEnqueue)}."); |
| | | 145 | | } |
| | | 146 | | |
| | | 147 | | if (subscriberOptions.BackgroundQueueCapacity <= 0) |
| | | 148 | | { |
| | | 149 | | throw new InvalidOperationException( |
| | | 150 | | $"{optionPath}.{nameof(RedisSubscriberOptions.BackgroundQueueCapacity)} must be explicitly confi |
| | | 151 | | $"when {nameof(RedisSubscriberOptions.AckMode)} is {nameof(RedisAckMode.AckAfterEnqueue)}."); |
| | | 152 | | } |
| | | 153 | | |
| | | 154 | | AsyncResponseChannelOptions.EnsureTimerBacked(subscriberOptions.BackgroundDrainTimeout, optionPath, name |
| | | 155 | | |
| | | 156 | | // Redis subscribers spend only the background drain at shutdown; the read loop |
| | | 157 | | // stops with the host token and the multiplexer teardown is not separately bounded. |
| | | 158 | | ShutdownBudgetValidator.Validate( |
| | | 159 | | "Redis", |
| | | 160 | | $"{nameof(RedisAsyncResponseTransportOptions)}.{nameof(RedisAsyncResponseTransportOptions.HostShutdo |
| | | 161 | | transportOptions.HostShutdownTimeout, |
| | | 162 | | ($"{optionPath}.{nameof(RedisSubscriberOptions.BackgroundDrainTimeout)}", subscriberOptions.Backgrou |
| | | 163 | | |
| | | 164 | | return; |
| | | 165 | | |
| | | 166 | | default: |
| | | 167 | | throw new InvalidOperationException( |
| | | 168 | | $"{optionPath}.{nameof(RedisSubscriberOptions.AckMode)} has unsupported value '{subscriberOptions.Ac |
| | | 169 | | } |
| | | 170 | | } |
| | | 171 | | |
| | | 172 | | /// <summary>Handles the delivered message.</summary> |
| | | 173 | | public abstract Task<RedisDispatchOutcome> HandleAsync( |
| | | 174 | | RedisStreamDelivery delivery, |
| | | 175 | | CancellationToken subscriberCancellationToken); |
| | | 176 | | |
| | | 177 | | /// <summary> |
| | | 178 | | /// Whether the dispatcher can accept more deliveries right now. Awaiting dispatchers always can |
| | | 179 | | /// (handlers run inline); the queued dispatcher returns <c>false</c> while its bounded queue is |
| | | 180 | | /// saturated so the subscriber stops pulling new entries into the pending-entry list instead of |
| | | 181 | | /// busy-reading and rejecting them. |
| | | 182 | | /// </summary> |
| | | 183 | | public virtual bool CanAcceptMore => true; |
| | | 184 | | |
| | | 185 | | /// <summary> |
| | | 186 | | /// How many entries the dispatcher can take right now without deferring any (ASB/SQS parity); |
| | | 187 | | /// unbounded for the awaiting dispatcher. The subscriber clamps every read and claim to it. |
| | | 188 | | /// </summary> |
| | | 189 | | public virtual int FreeCapacity => int.MaxValue; |
| | | 190 | | |
| | | 191 | | /// <summary>Releases resources held by this instance.</summary> |
| | | 192 | | public virtual ValueTask DisposeAsync() => ValueTask.CompletedTask; |
| | | 193 | | |
| | | 194 | | /// <summary>Runs the ExecuteHandlerAsync operation.</summary> |
| | | 195 | | protected async Task ExecuteHandlerAsync( |
| | | 196 | | RedisStreamDelivery delivery, |
| | | 197 | | CancellationToken cancellationToken, |
| | | 198 | | bool logFailures = true) |
| | | 199 | | { |
| | | 200 | | using var activity = AsyncResponseDiagnostics.StartActivity( |
| | | 201 | | "asyncresponse.redis.receive", |
| | | 202 | | ActivityKind.Consumer, |
| | | 203 | | delivery.CorrelationId); |
| | | 204 | | activity?.SetTag("asyncresponse.transport", "redis"); |
| | | 205 | | activity?.SetTag("asyncresponse.redis.role", _role.ToString()); |
| | | 206 | | activity?.SetTag("asyncresponse.redis.ack_mode", _subscriberOptions.AckMode.ToString()); |
| | | 207 | | activity?.SetTag("asyncresponse.redis.delivery_attempt", delivery.Attempt); |
| | | 208 | | activity?.SetTag("messaging.system", "redis"); |
| | | 209 | | activity?.SetTag("messaging.destination.name", _stream); |
| | | 210 | | activity?.SetTag("messaging.message.id", delivery.MessageId.ToString()); |
| | | 211 | | |
| | | 212 | | try |
| | | 213 | | { |
| | | 214 | | await _handler(delivery, cancellationToken).ConfigureAwait(false); |
| | | 215 | | } |
| | | 216 | | catch (Exception ex) |
| | | 217 | | { |
| | | 218 | | if (logFailures) |
| | | 219 | | { |
| | | 220 | | Logger.LogError( |
| | | 221 | | ex, |
| | | 222 | | "Redis stream message handling failed for {Stream}/{MessageId}.", |
| | | 223 | | _stream, |
| | | 224 | | delivery.MessageId.ToString()); |
| | | 225 | | } |
| | | 226 | | |
| | | 227 | | AsyncResponseDiagnostics.SetError(activity, ex); |
| | | 228 | | throw; |
| | | 229 | | } |
| | | 230 | | } |
| | | 231 | | |
| | | 232 | | /// <summary>Acknowledges the delivered message.</summary> |
| | | 233 | | protected Task AckAsync(RedisStreamDelivery delivery, CancellationToken cancellationToken) |
| | | 234 | | => _database.StreamAcknowledgeAsync( |
| | | 235 | | delivery.Stream, |
| | | 236 | | delivery.ConsumerGroup, |
| | | 237 | | delivery.MessageId, |
| | | 238 | | cancellationToken); |
| | | 239 | | |
| | | 240 | | /// <summary>Runs the AlreadyExceededDeliveryAttempts operation.</summary> |
| | | 241 | | protected bool AlreadyExceededDeliveryAttempts(RedisStreamDelivery delivery) |
| | | 242 | | => MaxDeliveryAttempts > 0 && delivery.Attempt > MaxDeliveryAttempts; |
| | | 243 | | |
| | | 244 | | /// <summary>Runs the ReachedDeliveryAttempts operation.</summary> |
| | | 245 | | protected bool ReachedDeliveryAttempts(RedisStreamDelivery delivery) |
| | | 246 | | => MaxDeliveryAttempts > 0 && delivery.Attempt >= MaxDeliveryAttempts; |
| | | 247 | | |
| | | 248 | | /// <summary>Moves the delivered message to dead-letter storage and acknowledges it.</summary> |
| | | 249 | | protected async Task DeadLetterAndAckAsync( |
| | | 250 | | RedisStreamDelivery delivery, |
| | | 251 | | Exception exception, |
| | | 252 | | string reason, |
| | | 253 | | CancellationToken cancellationToken) |
| | | 254 | | { |
| | | 255 | | if (TransportOptions.DeadLetterEnabled) |
| | | 256 | | { |
| | | 257 | | var fields = new[] |
| | | 258 | | { |
| | | 259 | | new NameValueEntry("sourceStream", delivery.Stream.ToString()), |
| | | 260 | | new NameValueEntry("consumerGroup", delivery.ConsumerGroup.ToString()), |
| | | 261 | | new NameValueEntry("subscriberRole", _role.ToString()), |
| | | 262 | | new NameValueEntry("messageId", delivery.MessageId.ToString()), |
| | | 263 | | new NameValueEntry("correlationId", delivery.CorrelationId ?? string.Empty), |
| | | 264 | | new NameValueEntry("attempt", delivery.Attempt), |
| | | 265 | | new NameValueEntry("reason", reason), |
| | | 266 | | new NameValueEntry("exceptionType", exception.GetType().FullName!), |
| | | 267 | | new NameValueEntry("exceptionMessage", exception.Message), |
| | | 268 | | new NameValueEntry("payload", delivery.Payload), |
| | | 269 | | new NameValueEntry("occurredAtUtc", DateTimeOffset.UtcNow.ToString("O")) |
| | | 270 | | }; |
| | | 271 | | |
| | | 272 | | await _database.StreamAddAsync( |
| | | 273 | | _keys.DeadLetterStream, |
| | | 274 | | fields, |
| | | 275 | | TransportOptions.DeadLetterStreamMaxLength, |
| | | 276 | | TransportOptions.UseApproximateStreamTrimming, |
| | | 277 | | cancellationToken).ConfigureAwait(false); |
| | | 278 | | } |
| | | 279 | | |
| | | 280 | | await AckAsync(delivery, cancellationToken).ConfigureAwait(false); |
| | | 281 | | } |
| | | 282 | | |
| | | 283 | | /// <summary> |
| | | 284 | | /// Dead-letters (when enabled) and ACKs a stream entry that could not be turned into a delivery — |
| | | 285 | | /// for example a foreign or malformed entry with no payload field, or a tombstone left behind when |
| | | 286 | | /// trimming evicts a still-pending entry. Without this, such an entry throws before |
| | | 287 | | /// <see cref="HandleAsync"/> runs, so it is never ACKed: the pending-claim loop re-claims it every |
| | | 288 | | /// cycle and the subscriber faults and restarts indefinitely while the entry never drains. |
| | | 289 | | /// </summary> |
| | | 290 | | public async Task DiscardUnprocessableAsync( |
| | | 291 | | RedisKey stream, |
| | | 292 | | RedisValue consumerGroup, |
| | | 293 | | StreamEntry entry, |
| | | 294 | | Exception failure, |
| | | 295 | | CancellationToken cancellationToken) |
| | | 296 | | { |
| | | 297 | | if (entry.Id.IsNull) |
| | | 298 | | { |
| | | 299 | | // A trimmed-while-pending tombstone (Redis 5/6 answer XCLAIM with a nil entry) carries |
| | | 300 | | // no id to ACK and no payload to record: sending its null id to XACK is rejected by the |
| | | 301 | | // client from inside the caller's catch, which replaced the original error, faulted the |
| | | 302 | | // subscriber, and re-dead-lettered the tombstone every claim cycle. The claim loop |
| | | 303 | | // drains it by its pending id instead; nothing to settle here. |
| | | 304 | | Logger.LogDebug(failure, "Redis claim on {Stream} returned a trimmed tombstone; skipping it.", _stream); |
| | | 305 | | return; |
| | | 306 | | } |
| | | 307 | | |
| | | 308 | | Logger.LogError( |
| | | 309 | | failure, |
| | | 310 | | "Redis entry {MessageId} on {Stream} could not be parsed into a delivery; dead-lettering and ACKing it to av |
| | | 311 | | entry.Id.ToString(), |
| | | 312 | | _stream); |
| | | 313 | | |
| | | 314 | | var delivery = new RedisStreamDelivery( |
| | | 315 | | stream, |
| | | 316 | | consumerGroup, |
| | | 317 | | entry.Id, |
| | | 318 | | DescribeRawEntry(entry), |
| | | 319 | | RedisCorrelationIdExtractor.TryReadField(entry, TransportOptions.CorrelationIdField), |
| | | 320 | | Attempt: 0, |
| | | 321 | | entry); |
| | | 322 | | |
| | | 323 | | // Settlement deliberately ignores cancellation (as every other settlement in this file |
| | | 324 | | // does): a shutdown landing between the dead-letter XADD and the XACK left the entry in |
| | | 325 | | // the PEL to be reclaimed and dead-lettered a SECOND time after restart. |
| | | 326 | | await DeadLetterAndAckAsync(delivery, failure, "unparsable_entry", CancellationToken.None).ConfigureAwait(false) |
| | | 327 | | } |
| | | 328 | | |
| | | 329 | | private static string DescribeRawEntry(StreamEntry entry) |
| | | 330 | | => entry.Values is { Length: > 0 } |
| | | 331 | | ? string.Join("; ", entry.Values.Select(value => $"{value.Name}={value.Value}")) |
| | | 332 | | : string.Empty; |
| | | 333 | | |
| | | 334 | | /// <summary>Runs the NotifyBackgroundFailureAsync operation.</summary> |
| | | 335 | | protected async ValueTask NotifyBackgroundFailureAsync( |
| | | 336 | | RedisStreamDelivery delivery, |
| | | 337 | | Exception exception) |
| | | 338 | | { |
| | | 339 | | var callback = _subscriberOptions.OnBackgroundFailure; |
| | | 340 | | if (callback is null) |
| | | 341 | | return; |
| | | 342 | | |
| | | 343 | | try |
| | | 344 | | { |
| | | 345 | | await callback(new RedisBackgroundFailureContext( |
| | | 346 | | _stream, |
| | | 347 | | _consumerGroup, |
| | | 348 | | _role.ToString(), |
| | | 349 | | delivery.MessageId.ToString(), |
| | | 350 | | delivery.CorrelationId, |
| | | 351 | | exception)).ConfigureAwait(false); |
| | | 352 | | } |
| | | 353 | | catch (Exception callbackException) |
| | | 354 | | { |
| | | 355 | | Logger.LogError( |
| | | 356 | | callbackException, |
| | | 357 | | "Redis background failure callback failed for already-ACKed message {MessageId} on {Stream}.", |
| | | 358 | | delivery.MessageId.ToString(), |
| | | 359 | | _stream); |
| | | 360 | | } |
| | | 361 | | } |
| | | 362 | | } |
| | | 363 | | |
| | | 364 | | internal sealed class AwaitingRedisMessageDispatcher( |
| | | 365 | | Func<RedisStreamDelivery, CancellationToken, Task> handler, |
| | | 366 | | IRedisStreamDatabase database, |
| | | 367 | | RedisAsyncResponseTransportOptions transportOptions, |
| | | 368 | | RedisSubscriberOptions subscriberOptions, |
| | | 369 | | ILogger logger, |
| | | 370 | | RedisKey stream, |
| | | 371 | | RedisValue consumerGroup, |
| | | 372 | | RedisSubscriberRole role) |
| | | 373 | | : RedisMessageDispatcher(handler, database, transportOptions, subscriberOptions, logger, stream, consumerGroup, role |
| | | 374 | | { |
| | | 375 | | /// <summary>Handles the delivered message.</summary> |
| | | 376 | | public override async Task<RedisDispatchOutcome> HandleAsync( |
| | | 377 | | RedisStreamDelivery delivery, |
| | | 378 | | CancellationToken subscriberCancellationToken) |
| | | 379 | | { |
| | | 380 | | if (AlreadyExceededDeliveryAttempts(delivery)) |
| | | 381 | | { |
| | | 382 | | await TryDeadLetterAndAckAsync( |
| | | 383 | | delivery, |
| | | 384 | | new InvalidOperationException($"Redis message exceeded {MaxDeliveryAttempts} delivery attempts."), |
| | | 385 | | "max_delivery_attempts_exceeded").ConfigureAwait(false); |
| | | 386 | | return RedisDispatchOutcome.Processed; |
| | | 387 | | } |
| | | 388 | | |
| | | 389 | | try |
| | | 390 | | { |
| | | 391 | | await ExecuteHandlerAsync(delivery, subscriberCancellationToken).ConfigureAwait(false); |
| | | 392 | | } |
| | | 393 | | catch (OperationCanceledException) when (subscriberCancellationToken.IsCancellationRequested) |
| | | 394 | | { |
| | | 395 | | throw; |
| | | 396 | | } |
| | | 397 | | catch (Exception ex) when (ReachedDeliveryAttempts(delivery)) |
| | | 398 | | { |
| | | 399 | | Logger.LogWarning( |
| | | 400 | | ex, |
| | | 401 | | "Redis message {MessageId} reached max delivery attempts ({MaxDeliveryAttempts}); writing to dead-letter |
| | | 402 | | delivery.MessageId.ToString(), |
| | | 403 | | MaxDeliveryAttempts); |
| | | 404 | | await TryDeadLetterAndAckAsync(delivery, ex, "handler_failed_max_attempts").ConfigureAwait(false); |
| | | 405 | | return RedisDispatchOutcome.Processed; |
| | | 406 | | } |
| | | 407 | | catch |
| | | 408 | | { |
| | | 409 | | // Leave the entry pending. The subscriber's pending-claim loop reclaims it after |
| | | 410 | | // PendingMessageMinIdleTime, giving Redis-backed retry without a hot loop. |
| | | 411 | | return RedisDispatchOutcome.Processed; |
| | | 412 | | } |
| | | 413 | | |
| | | 414 | | // The ACK sits outside the handler's try/catch: a transient XACK failure after a |
| | | 415 | | // successful handler must not be misread as a handler failure — dead-lettering or leaving |
| | | 416 | | // it for reclaim here would redeliver (or bury) work whose side effects already completed. |
| | | 417 | | // Swallow and log instead; the entry stays pending and at-least-once redelivery applies. |
| | | 418 | | // Settlement deliberately ignores cancellation (as every sibling transport does): the |
| | | 419 | | // handler already completed, and abandoning the XACK on shutdown leaves the entry in the |
| | | 420 | | // PEL to be reclaimed and re-run after restart. |
| | | 421 | | try |
| | | 422 | | { |
| | | 423 | | await AckAsync(delivery, CancellationToken.None).ConfigureAwait(false); |
| | | 424 | | } |
| | | 425 | | catch (Exception ex) |
| | | 426 | | { |
| | | 427 | | Logger.LogWarning( |
| | | 428 | | ex, |
| | | 429 | | "Failed to ACK Redis message {MessageId} on {Stream} after a successful handler; the entry stays pending |
| | | 430 | | delivery.MessageId.ToString(), |
| | | 431 | | delivery.Stream.ToString()); |
| | | 432 | | } |
| | | 433 | | |
| | | 434 | | return RedisDispatchOutcome.Processed; |
| | | 435 | | } |
| | | 436 | | |
| | | 437 | | /// <summary> |
| | | 438 | | /// Burial that never throws (queued-dispatcher and DB-transport parity: "a burial that throws |
| | | 439 | | /// is a burial that failed"). Unguarded, a dead-letter XADD that failed — MISCONF/OOM, the |
| | | 440 | | /// adapter's timeout, a WRONGTYPE on the dead-letter key — escaped past the XACK to the |
| | | 441 | | /// supervisor, which restarted the subscriber; the pending-claim loop then re-claimed the |
| | | 442 | | /// same entry every cycle and the whole stream stopped draining. Settlement deliberately |
| | | 443 | | /// ignores cancellation: a shutdown landing between the XADD and the XACK would leave the |
| | | 444 | | /// entry in the PEL to be reclaimed and dead-lettered a SECOND time. |
| | | 445 | | /// </summary> |
| | | 446 | | private async Task TryDeadLetterAndAckAsync(RedisStreamDelivery delivery, Exception exception, string reason) |
| | | 447 | | { |
| | | 448 | | try |
| | | 449 | | { |
| | | 450 | | await DeadLetterAndAckAsync(delivery, exception, reason, CancellationToken.None).ConfigureAwait(false); |
| | | 451 | | } |
| | | 452 | | catch (Exception deadLetterException) |
| | | 453 | | { |
| | | 454 | | Logger.LogError( |
| | | 455 | | deadLetterException, |
| | | 456 | | "Failed to dead-letter Redis message {MessageId} on {Stream} ({Reason}); the entry stays pending and is |
| | | 457 | | delivery.MessageId.ToString(), |
| | | 458 | | delivery.Stream.ToString(), |
| | | 459 | | reason); |
| | | 460 | | } |
| | | 461 | | } |
| | | 462 | | } |
| | | 463 | | |
| | | 464 | | internal sealed class QueuedRedisMessageDispatcher : RedisMessageDispatcher |
| | | 465 | | { |
| | | 466 | | private readonly Channel<RedisStreamDelivery> _queue; |
| | | 467 | | private readonly Task[] _workers; |
| | | 468 | | private readonly CancellationTokenSource _drainCancellation = new(); |
| | | 469 | | private readonly TimeSpan _drainTimeout; |
| | | 470 | | private readonly int _capacity; |
| | | 471 | | private readonly string _stream; |
| | | 472 | | private int _pendingCount; |
| | | 473 | | private int _runningCount; |
| | | 474 | | private int _disposeStarted; |
| | | 475 | | |
| | | 476 | | /// <summary>Runs the QueuedRedisMessageDispatcher operation.</summary> |
| | | 477 | | public QueuedRedisMessageDispatcher( |
| | | 478 | | Func<RedisStreamDelivery, CancellationToken, Task> handler, |
| | | 479 | | IRedisStreamDatabase database, |
| | | 480 | | RedisAsyncResponseTransportOptions transportOptions, |
| | | 481 | | RedisSubscriberOptions subscriberOptions, |
| | | 482 | | ILogger logger, |
| | | 483 | | RedisKey stream, |
| | | 484 | | RedisValue consumerGroup, |
| | | 485 | | RedisSubscriberRole role) |
| | | 486 | | : base(handler, database, transportOptions, subscriberOptions, logger, stream, consumerGroup, role) |
| | | 487 | | { |
| | | 488 | | _stream = stream.ToString(); |
| | | 489 | | _drainTimeout = subscriberOptions.BackgroundDrainTimeout; |
| | | 490 | | _capacity = subscriberOptions.BackgroundQueueCapacity; |
| | | 491 | | _queue = Channel.CreateBounded<RedisStreamDelivery>(new BoundedChannelOptions(subscriberOptions.BackgroundQueueC |
| | | 492 | | { |
| | | 493 | | AllowSynchronousContinuations = false, |
| | | 494 | | FullMode = BoundedChannelFullMode.Wait, |
| | | 495 | | SingleReader = subscriberOptions.BackgroundWorkerCount == 1, |
| | | 496 | | SingleWriter = false |
| | | 497 | | }); |
| | | 498 | | |
| | | 499 | | _workers = Enumerable.Range(0, subscriberOptions.BackgroundWorkerCount) |
| | | 500 | | .Select(workerIndex => Task.Run(() => RunWorkerAsync(workerIndex))) |
| | | 501 | | .ToArray(); |
| | | 502 | | |
| | | 503 | | Logger.LogInformation( |
| | | 504 | | "Created Redis ACK-after-enqueue dispatcher for {Stream} with {WorkerCount} worker(s), queue capacity {Queue |
| | | 505 | | _stream, |
| | | 506 | | subscriberOptions.BackgroundWorkerCount, |
| | | 507 | | subscriberOptions.BackgroundQueueCapacity, |
| | | 508 | | _drainTimeout); |
| | | 509 | | } |
| | | 510 | | |
| | | 511 | | internal int PendingCount => Volatile.Read(ref _pendingCount); |
| | | 512 | | internal int RunningCount => Volatile.Read(ref _runningCount); |
| | | 513 | | |
| | | 514 | | public override bool CanAcceptMore => Volatile.Read(ref _pendingCount) < _capacity; |
| | | 515 | | |
| | | 516 | | public override int FreeCapacity => Math.Max(0, _capacity - Volatile.Read(ref _pendingCount)); |
| | | 517 | | |
| | | 518 | | /// <summary>Handles the delivered message.</summary> |
| | | 519 | | public override async Task<RedisDispatchOutcome> HandleAsync( |
| | | 520 | | RedisStreamDelivery delivery, |
| | | 521 | | CancellationToken subscriberCancellationToken) |
| | | 522 | | { |
| | | 523 | | // Pre-execution cap, BEFORE the enqueue-and-ACK (awaiting-dispatcher parity): the |
| | | 524 | | // pending-claim loop feeds this dispatcher real XPENDING delivery counts too, and without |
| | | 525 | | // the check an over-cap entry — deferred under backpressure and reclaimed each cycle, or |
| | | 526 | | // re-claimed after a swallowed post-enqueue ACK failure — was re-enqueued and re-executed |
| | | 527 | | // forever, with nothing ever consulting MaxDeliveryAttempts to bury it. |
| | | 528 | | if (AlreadyExceededDeliveryAttempts(delivery)) |
| | | 529 | | { |
| | | 530 | | await DeadLetterAndAckAsync( |
| | | 531 | | delivery, |
| | | 532 | | new InvalidOperationException($"Redis message exceeded {MaxDeliveryAttempts} delivery attempts."), |
| | | 533 | | "max_delivery_attempts_exceeded", |
| | | 534 | | CancellationToken.None).ConfigureAwait(false); |
| | | 535 | | return RedisDispatchOutcome.Processed; |
| | | 536 | | } |
| | | 537 | | |
| | | 538 | | Interlocked.Increment(ref _pendingCount); |
| | | 539 | | if (!_queue.Writer.TryWrite(delivery)) |
| | | 540 | | { |
| | | 541 | | Interlocked.Decrement(ref _pendingCount); |
| | | 542 | | Logger.LogWarning( |
| | | 543 | | "Redis background queue rejected message {MessageId} for {Stream}; leaving it pending for retry. Pending |
| | | 544 | | delivery.MessageId.ToString(), |
| | | 545 | | _stream, |
| | | 546 | | PendingCount, |
| | | 547 | | RunningCount); |
| | | 548 | | return RedisDispatchOutcome.Deferred; |
| | | 549 | | } |
| | | 550 | | |
| | | 551 | | // The entry now belongs to a background worker, which decrements _pendingCount when it dequeues. |
| | | 552 | | // Do not touch the counter again here, even if the ACK below fails — otherwise it double-counts. |
| | | 553 | | // Settlement deliberately ignores cancellation (as every sibling transport does): a graceful |
| | | 554 | | // shutdown drains the background queue and runs this entry, so abandoning the XACK on the |
| | | 555 | | // stopping token would leave completed work in the PEL to be reclaimed and re-run. |
| | | 556 | | try |
| | | 557 | | { |
| | | 558 | | await AckAsync(delivery, CancellationToken.None).ConfigureAwait(false); |
| | | 559 | | } |
| | | 560 | | catch (Exception ex) |
| | | 561 | | { |
| | | 562 | | Logger.LogError( |
| | | 563 | | ex, |
| | | 564 | | "Failed to ACK Redis message {MessageId} for {Stream} after enqueue; it is being processed but Redis wil |
| | | 565 | | delivery.MessageId.ToString(), |
| | | 566 | | _stream); |
| | | 567 | | } |
| | | 568 | | |
| | | 569 | | return RedisDispatchOutcome.Processed; |
| | | 570 | | } |
| | | 571 | | |
| | | 572 | | /// <summary>Releases resources held by this instance.</summary> |
| | | 573 | | public override async ValueTask DisposeAsync() |
| | | 574 | | { |
| | | 575 | | if (Interlocked.Exchange(ref _disposeStarted, 1) != 0) |
| | | 576 | | return; |
| | | 577 | | |
| | | 578 | | Logger.LogInformation( |
| | | 579 | | "Draining Redis ACK-after-enqueue dispatcher for {Stream}. Pending={PendingCount}, Running={RunningCount}.", |
| | | 580 | | _stream, |
| | | 581 | | PendingCount, |
| | | 582 | | RunningCount); |
| | | 583 | | _queue.Writer.TryComplete(); |
| | | 584 | | |
| | | 585 | | try |
| | | 586 | | { |
| | | 587 | | await Task.WhenAll(_workers).WaitAsync(_drainTimeout).ConfigureAwait(false); |
| | | 588 | | _drainCancellation.Dispose(); |
| | | 589 | | } |
| | | 590 | | catch (TimeoutException ex) |
| | | 591 | | { |
| | | 592 | | _drainCancellation.Cancel(); |
| | | 593 | | Logger.LogWarning( |
| | | 594 | | ex, |
| | | 595 | | "Timed out while draining Redis ACK-after-enqueue dispatcher for {Stream}. Pending={PendingCount}, Runni |
| | | 596 | | _stream, |
| | | 597 | | PendingCount, |
| | | 598 | | RunningCount); |
| | | 599 | | |
| | | 600 | | _ = Task.WhenAll(_workers).ContinueWith( |
| | | 601 | | _ => _drainCancellation.Dispose(), |
| | | 602 | | CancellationToken.None, |
| | | 603 | | TaskContinuationOptions.ExecuteSynchronously, |
| | | 604 | | TaskScheduler.Default); |
| | | 605 | | } |
| | | 606 | | catch (Exception ex) |
| | | 607 | | { |
| | | 608 | | // A worker faulted outside its own handler guard (DB/NATS dispatcher parity). WhenAll |
| | | 609 | | // only completes once every worker has finished, so the source is safe to dispose here |
| | | 610 | | // — and the fault must not escape DisposeAsync and mask the real shutdown path. |
| | | 611 | | Logger.LogDebug(ex, "Redis ACK-after-enqueue dispatcher drain for {Stream} ended with an error.", _stream); |
| | | 612 | | _drainCancellation.Dispose(); |
| | | 613 | | } |
| | | 614 | | } |
| | | 615 | | |
| | | 616 | | private async Task RunWorkerAsync(int workerIndex) |
| | | 617 | | { |
| | | 618 | | await foreach (var delivery in _queue.Reader.ReadAllAsync().ConfigureAwait(false)) |
| | | 619 | | { |
| | | 620 | | Interlocked.Decrement(ref _pendingCount); |
| | | 621 | | Interlocked.Increment(ref _runningCount); |
| | | 622 | | |
| | | 623 | | // Once the drain budget has lapsed, STOP executing. The token below cannot stop the |
| | | 624 | | // real handler — it is `_ingress.HandleWorkerMessageAsync(payload)`, whose target takes |
| | | 625 | | // no CancellationToken — so nothing ever raised the OperationCanceledException the arm |
| | | 626 | | // below was written for, the loop kept starting fresh work past the budget, and every |
| | | 627 | | // entry still queued at process exit vanished with no record (they were ACKed at |
| | | 628 | | // enqueue, so Redis will not redeliver them). Route them through the same |
| | | 629 | | // OnBackgroundFailure/dead-letter path instead of losing them silently. |
| | | 630 | | if (_drainCancellation.IsCancellationRequested) |
| | | 631 | | { |
| | | 632 | | var lapsed = new OperationCanceledException( |
| | | 633 | | "The ACK-after-enqueue drain budget lapsed before this already-ACKed message was handled."); |
| | | 634 | | |
| | | 635 | | Logger.LogWarning( |
| | | 636 | | "Redis background handler for already-ACKed message {MessageId} on {Stream} was not started: the dis |
| | | 637 | | delivery.MessageId.ToString(), |
| | | 638 | | _stream); |
| | | 639 | | |
| | | 640 | | await NotifyBackgroundFailureAsync(delivery, lapsed).ConfigureAwait(false); |
| | | 641 | | |
| | | 642 | | try |
| | | 643 | | { |
| | | 644 | | await DeadLetterAndAckAsync( |
| | | 645 | | delivery, |
| | | 646 | | lapsed, |
| | | 647 | | "drain_budget_lapsed_after_ack", |
| | | 648 | | CancellationToken.None).ConfigureAwait(false); |
| | | 649 | | } |
| | | 650 | | catch (Exception deadLetterException) |
| | | 651 | | { |
| | | 652 | | Logger.LogError( |
| | | 653 | | deadLetterException, |
| | | 654 | | "Failed to dead-letter undrained Redis message {MessageId} on {Stream}.", |
| | | 655 | | delivery.MessageId.ToString(), |
| | | 656 | | _stream); |
| | | 657 | | } |
| | | 658 | | |
| | | 659 | | Interlocked.Decrement(ref _runningCount); |
| | | 660 | | continue; |
| | | 661 | | } |
| | | 662 | | |
| | | 663 | | try |
| | | 664 | | { |
| | | 665 | | await ExecuteHandlerAsync( |
| | | 666 | | delivery, |
| | | 667 | | _drainCancellation.Token, |
| | | 668 | | logFailures: false).ConfigureAwait(false); |
| | | 669 | | } |
| | | 670 | | catch (OperationCanceledException ex) when (_drainCancellation.IsCancellationRequested) |
| | | 671 | | { |
| | | 672 | | // The drain budget lapsed with this already-ACKed entry still unprocessed: Redis |
| | | 673 | | // will not redeliver it, so surface the drop through OnBackgroundFailure instead of |
| | | 674 | | // losing it silently. |
| | | 675 | | Logger.LogWarning( |
| | | 676 | | "Redis background handler for already-ACKed message {MessageId} on {Stream} was canceled during disp |
| | | 677 | | delivery.MessageId.ToString(), |
| | | 678 | | _stream); |
| | | 679 | | await NotifyBackgroundFailureAsync(delivery, ex).ConfigureAwait(false); |
| | | 680 | | } |
| | | 681 | | catch (Exception ex) |
| | | 682 | | { |
| | | 683 | | Logger.LogError( |
| | | 684 | | ex, |
| | | 685 | | "Redis background handler failed for already-ACKed message {MessageId} on {Stream}.", |
| | | 686 | | delivery.MessageId.ToString(), |
| | | 687 | | _stream); |
| | | 688 | | await NotifyBackgroundFailureAsync(delivery, ex).ConfigureAwait(false); |
| | | 689 | | |
| | | 690 | | try |
| | | 691 | | { |
| | | 692 | | await DeadLetterAndAckAsync( |
| | | 693 | | delivery, |
| | | 694 | | ex, |
| | | 695 | | "background_handler_failed_after_ack", |
| | | 696 | | CancellationToken.None).ConfigureAwait(false); |
| | | 697 | | } |
| | | 698 | | catch (Exception deadLetterException) |
| | | 699 | | { |
| | | 700 | | Logger.LogError( |
| | | 701 | | deadLetterException, |
| | | 702 | | "Failed to dead-letter already-ACKed Redis message {MessageId} on {Stream}.", |
| | | 703 | | delivery.MessageId.ToString(), |
| | | 704 | | _stream); |
| | | 705 | | } |
| | | 706 | | } |
| | | 707 | | finally |
| | | 708 | | { |
| | | 709 | | Interlocked.Decrement(ref _runningCount); |
| | | 710 | | } |
| | | 711 | | } |
| | | 712 | | } |
| | | 713 | | } |