Requeue All

Overview

Requeue all moves an entire batch of polled messages to a different channel in one server-side operation, without republishing them from the client. Reach for it when you need to make a routing decision after looking at a batch — shovel a stuck batch into a review queue, redirect it to a priority pipeline, or migrate messages off a channel that's being retired, all while the source queue is cleared atomically.

It works against the batch returned by a manual poll: after receiving messages with AutoAck = false, call batch.ReQueueAllAsync(destinationChannel) to move every message held in that batch to the destination channel, removing them from the source at the same instant. The messages keep their original body, tags, and policies — the broker relocates them, it doesn't recreate them.

Gotchas: requeuing is all-or-nothing for the batch — there's no per-message filter, so split the batch yourself first if only some messages should move. The destination channel is an ordinary queue with no special semantics; nothing consumes it automatically. And the operation only affects messages still locked in the batch — anything already acked or expired out of it is gone before ReQueueAllAsync runs.

Prerequisites

• KubeMQ server running on localhost:50000
• C# SDK installed (dotnet add package KubeMQ.SDK.CSharp)

Code

// KubeMQ .NET SDK — QueuesStream: ReQueueAll via Batch
//
// This example demonstrates receiving messages via the downstream receiver API
// and re-routing all messages to a different channel using batch.ReQueueAllAsync().
// This is useful for dead-letter queue (DLQ) patterns.
//
// Prerequisites:
//   - KubeMQ server running on localhost:50000
//   - Send some messages to "csharp-queues.requeue-all" first
//   - dotnet run

using KubeMQ.Sdk.Client;
using KubeMQ.Sdk.Queues;

await using var client = new KubeMQClient(new KubeMQClientOptions
{
    ClientId = "csharp-queues-requeue-all-client",
});
await client.ConnectAsync();

Console.WriteLine("Connected to KubeMQ server");

await using var receiver = await client.CreateQueueDownstreamReceiverAsync();

var batch = await receiver.PollAsync(new QueuePollRequest
{
    Channel = "csharp-queues.requeue-all",
    MaxMessages = 10,
    WaitTimeoutSeconds = 5,
    AutoAck = false,
});

Console.WriteLine($"Received {batch.Messages.Count} messages");

if (batch.HasMessages)
{
    await batch.ReQueueAllAsync("csharp-queues.dlq");
    Console.WriteLine("All messages re-queued to 'csharp-queues.dlq'.");
}

Console.WriteLine("Done.");

How It Works

• batch.ReQueueAllAsync(destinationChannel) atomically moves all messages in the locked batch to the specified destination channel in one server-side operation.
• Messages are not re-sent by the client — the broker moves them internally, preserving their original metadata, body, and policy fields.
• This is a key building block for DLQ shovelling: a background worker polls the dead-letter queue and re-routes fixable messages back to the source queue after an operator corrects the issue.
• The destination can be any channel name — including the original source channel for a simple retry, or a different queue for escalation routing.

Related

• Pattern overview
• C# SDK Reference
• Send & Receive
• Ack All