Purge Queue

Overview

Purging a queue is a management-plane operation for wiping a channel's backlog without receiving and discarding messages one at a time. Reach for it when a bad producer floods a channel, when you need a clean slate between test runs, or when you're resetting a queue during a maintenance window — all without deleting and recreating the channel itself.

PurgeQueueAsync(channelName) tells the broker directly to acknowledge and drop every message still pending on the channel, entirely server-side. The returned result's AffectedMessages field reports exactly how many messages were removed, so a 0 tells you the queue was already empty.

Gotchas: the purge is irreversible — there's no undo once messages are removed. It only reaches messages still waiting in the queue; anything already delivered to and held by an active consumer is untouched, so a purge run right after a receive can still leave stragglers. And purging empties the channel, it doesn't delete it — new messages can be enqueued immediately afterward.

Prerequisites

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

Code

// KubeMQ .NET SDK — Management: Purge Queue
//
// This example demonstrates purging all messages from a queue channel
// using the PurgeQueueAsync API.
//
// Prerequisites:
//   - KubeMQ server running on localhost:50000
//   - dotnet run

using KubeMQ.Sdk.Client;

await using var client = new KubeMQClient(new KubeMQClientOptions
{
    ClientId = "csharp-config-purge-queue-client",
});
await client.ConnectAsync();

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

var result = await client.PurgeQueueAsync("csharp-config.purge-queue");
Console.WriteLine($"Purged {result.AffectedMessages} messages");

Console.WriteLine("Done.");

How It Works

• PurgeQueueAsync(channelName) sends a server-side purge request; the broker atomically removes all pending (unacknowledged) messages from the queue channel.
• The returned result contains AffectedMessages — the count of messages that were deleted; a value of 0 means the queue was already empty.
• Purging is irreversible: deleted messages cannot be recovered, so use with care in production.
• The channel itself is not deleted by a purge; new messages can be enqueued immediately after.

Related

• C# SDK Reference
• Create Channel
• Delete Channel