public void starts_low()
{
using (var sut = new DynamicThrottling(100, 10, 3, 5, 1, 8000))
{
Assert.IsTrue(10 == sut.AvailableDegreesOfParallelism);
}
}
public void increases_on_completed_work()
{
using (var sut = new DynamicThrottling(100, 10, 3, 5, 1, 8000))
{
sut.NotifyWorkStarted();
var startingValue = sut.AvailableDegreesOfParallelism;
sut.NotifyWorkCompleted();
Assert.IsTrue(startingValue < sut.AvailableDegreesOfParallelism);
}
}
public void decreases_on_penalize()
{
using (var sut = new DynamicThrottling(100, 10, 3, 5, 1, 8000))
{
IncreaseDegreesOfParallelism(sut);
sut.NotifyWorkStarted();
var startingValue = sut.AvailableDegreesOfParallelism;
sut.Penalize();
Assert.IsTrue(startingValue > sut.AvailableDegreesOfParallelism);
}
}
public void penalize_decreases_less_than_completed_with_error()
{
using (var sut1 = new DynamicThrottling(100, 10, 3, 5, 1, 8000))
using (var sut2 = new DynamicThrottling(100, 10, 3, 5, 1, 8000))
{
IncreaseDegreesOfParallelism(sut1);
IncreaseDegreesOfParallelism(sut2);
sut1.NotifyWorkStarted();
sut2.NotifyWorkStarted();
sut1.Penalize();
sut2.NotifyWorkCompletedWithError();
Assert.IsTrue(sut1.AvailableDegreesOfParallelism > sut2.AvailableDegreesOfParallelism);
}
}
protected SubscriptionReceiver(ServiceBusSettings settings, string topic, string subscription, bool processInParallel, ISubscriptionReceiverInstrumentation instrumentation, int maxNumberRetry, RetryStrategy backgroundRetryStrategy)
{
this.settings = settings;
this.topic = topic;
this.subscription = subscription;
this.processInParallel = processInParallel;
this.instrumentation = instrumentation;
var messagingFactory = MessagingFactory.CreateFromConnectionString(this.settings.ConnectionString);
this.client = messagingFactory.CreateSubscriptionClient(topic, subscription);
if (this.processInParallel)
{
this.client.PrefetchCount = 500;
}
else
{
this.client.PrefetchCount = 100;
}
this.dynamicThrottling =
new DynamicThrottling(
maxDegreeOfParallelism: 10000,
minDegreeOfParallelism: 50,
penaltyAmount: 3,
workFailedPenaltyAmount: 5,
workCompletedParallelismGain: 1,
intervalForRestoringDegreeOfParallelism: 8000);
this.retryStrategy = backgroundRetryStrategy;
this.maxNumberRetry = maxNumberRetry;
this.receiveRetryPolicy = new RetryPolicy<ServiceBusTransientErrorDetectionStrategy>(backgroundRetryStrategy);
this.receiveRetryPolicy.Retrying += (s, e) =>
{
this.dynamicThrottling.Penalize();
Trace.TraceWarning(
"An error occurred in attempt number {1} to receive a message from subscription {2}: {0}",
e.LastException.Message,
e.CurrentRetryCount,
this.subscription);
};
}
private static void IncreaseDegreesOfParallelism(DynamicThrottling sut)
{
for (int i = 0; i < 10; i++)
{
// increase degrees to avoid being in the minimum boundary
sut.NotifyWorkStarted();
sut.NotifyWorkCompleted();
}
}