Joseph Doherty
69 lines
2.6 KiB
C#
69 lines
2.6 KiB
C#
using Grpc.Core;
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using Microsoft.Extensions.Logging;
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using MxGateway.Contracts.Proto;
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using Polly;
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using Polly.Retry;
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namespace MxGateway.Client;
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/// <summary>Factory and helpers for exponential-backoff retry policies on transient gRPC failures.</summary>
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internal static class MxGatewayClientRetryPolicy
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{
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/// <summary>Creates a Polly ResiliencePipeline that retries transient gRPC failures with exponential backoff.</summary>
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/// <param name="options">Retry configuration (max attempts, delay bounds, jitter).</param>
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/// <param name="logger">Optional logger for retry diagnostics.</param>
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public static ResiliencePipeline Create(
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MxGatewayClientRetryOptions options,
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ILogger? logger)
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{
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ArgumentNullException.ThrowIfNull(options);
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options.Validate();
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return new ResiliencePipelineBuilder()
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.AddRetry(new RetryStrategyOptions
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{
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MaxRetryAttempts = Math.Max(0, options.MaxAttempts - 1),
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BackoffType = DelayBackoffType.Exponential,
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UseJitter = options.UseJitter,
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Delay = options.Delay,
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MaxDelay = options.MaxDelay,
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ShouldHandle = new PredicateBuilder().Handle<Exception>(IsTransientGrpcFailure),
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OnRetry = args =>
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{
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logger?.LogDebug(
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args.Outcome.Exception,
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"Retrying MXAccess Gateway client call after transient gRPC failure. Attempt {Attempt}.",
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args.AttemptNumber + 1);
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return default;
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},
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})
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.Build();
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}
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/// <summary>Returns whether a command kind is eligible for automatic retry on transient failures.</summary>
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/// <param name="kind">The command kind to check.</param>
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public static bool IsRetryableCommand(MxCommandKind kind)
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{
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return kind is MxCommandKind.Ping
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or MxCommandKind.GetSessionState
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or MxCommandKind.GetWorkerInfo;
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}
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private static bool IsTransientGrpcFailure(Exception exception)
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{
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return exception switch
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{
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RpcException rpcException => IsTransientStatus(rpcException.StatusCode),
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MxGatewayException { InnerException: RpcException rpcException } => IsTransientStatus(rpcException.StatusCode),
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_ => false,
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};
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}
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private static bool IsTransientStatus(StatusCode statusCode)
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{
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return statusCode is StatusCode.Unavailable
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or StatusCode.DeadlineExceeded
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or StatusCode.ResourceExhausted;
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}
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}
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