# Kill Switch

A Kill Switch is used to prevent failing consumers from moving all the messages from the input queue to the error queue. By monitoring message consumption and tracking message successes and failures, a Kill Switch stops the receive endpoint when a trip threshold has been reached.

Typically, consumer exceptions are transient issues and suspending consumption until a later time when the transient issue may have been resolved.

# Configuration

A Kill Switch can be configured on an individual receive endpoint or all receive endpoints on the bus. To configure a kill switch on all receive endpoints, add the UseKillSwitch method as shown.

var busControl = Bus.Factory.CreateUsingRabbitMq(cfg =>
{
    cfg.UseKillSwitch(options => options
        .SetActivationThreshold(10)
        .SetTripThreshold(0.15)
        .SetRestartTimeout(m: 1));

    cfg.ReceiveEndpoint("some-queue", e =>
    {
        e.Consumer<SomeConsumer>();
    });
});

In the above example, the kill switch will activate after 10 messages have been consumed. If the ratio of failures/attempts exceeds 15%, the kill switch with trip and stop the receive endpoint. After 1 minute, the receive endpoint will be restarted. Once restarted, if exceptions are still observed, the receive endpoint will be stopped again for 1 minute.

To configure the kill switch on a receive endpoint, the syntax is the same as shown.

var busControl = Bus.Factory.CreateUsingRabbitMq(cfg =>
{
    cfg.ReceiveEndpoint("some-queue", e =>
    {
        e.UseKillSwitch(options => options
            .SetActivationThreshold(10)
            .SetTripThreshold(0.15)
            .SetRestartTimeout(m: 1));

        e.Consumer<SomeConsumer>();
    });
});

# Options