Proto.Util.Throttle

The Throttle class is a utility class used to prevent event flooding. The Throttle is similar to a circuit breaker, but instead of getting triggered by failure, it triggers by a surge of events in a short time.

This can be very useful in scenarios where you consume large number of events, be it from an HTTP endpoint, or a message queue or log such as RabbitMQ or Kafka. Under normal conditions, you might want to fully log error events if something fails during processing, but in case there is a flood of errors, you might not want to fill up your log system with thousands or millions of log entries. Here is where you can benefit from using the Throttle class.

Setting up:

private readonly ShouldThrottle _shouldThrottle;

/* ... */

_shouldThrottle = Throttle.Create( 
    // max number of events/calls
    10,
    
    // in this duration
    TimeSpan.FromSeconds(5),
    
    // callback for when valve opens back up again
    count => _logger.LogInformation("Throttled {LogCount} logs for component xyz", count)
);

Usage:

catch(Exception e)
{
    if (_shouldThrottle().IsOpen()) //if the valve of the throttle is open, log the event
        _logger.LogError(e, "Some operation failed");
}

_shouldThrottle will internally count the number calls made to it and close the valve if the number of calls exceeds the configuration provided when setting it up.