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.

ack_all_queue_messages tells the broker directly to acknowledge and drop every message still pending on the channel, entirely server-side. You give it a channel and a wait_time_seconds drain window so the broker can settle in-flight deliveries before finalizing, and it hands back an affected_messages count so you can confirm exactly how much was cleared.

Gotchas: the purge is irreversible — there's no undo once messages are acknowledged away. 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 sent immediately afterward.

Prerequisites

• KubeMQ server running on localhost:50000
• Rust SDK installed (cargo add kubemq)

Code

use kubemq::prelude::*;
use kubemq::{AckAllQueueMessagesRequest, QueueMessageBuilder};

#[tokio::main]
async fn main() -> kubemq::Result<()> {
    let client = KubemqClient::builder()
        .host("localhost")
        .port(50000)
        .build()
        .await?;

    let channel = "rust-management.purge-queue";

    for i in 0..10 {
        let msg = QueueMessageBuilder::new()
            .channel(channel)
            .body(format!("purge-msg-{}", i).into_bytes())
            .build();
        client.send_queue_message(msg).await?;
    }
    println!("Sent 10 messages");

    let req = AckAllQueueMessagesRequest {
        request_id: String::new(),
        client_id: String::new(),
        channel: channel.to_string(),
        wait_time_seconds: 5,
    };
    let resp = client.ack_all_queue_messages(&req).await?;
    println!("Purged {} messages from queue", resp.affected_messages);

    client.close().await?;
    Ok(())
}

How It Works

• ack_all_queue_messages acknowledges (and removes) all pending messages from the queue.
• This is equivalent to purging the queue — all messages are consumed without processing.
• Review timeouts, channel names, and client IDs before running against shared environments.
• Run the program while the server from the prerequisites is available.

Related

• Queues overview
• Rust SDK Reference
• Ack All