public void When_Canary_Fails_Circuit_Opens()
{
var config = new CircuitBreakerConfiguration
{
VolumeThreshold = 1,
SleepWindow = TimeSpan.FromMilliseconds(50)
};
var circuitBreaker = new CircuitBreaker(config);
circuitBreaker.MarkFailure();
Thread.Sleep(config.SleepWindow.Add(TimeSpan.FromMilliseconds(1)));
circuitBreaker.Track();
Assert.Equal(CircuitBreakerState.HalfOpen, circuitBreaker.State);
Assert.False(circuitBreaker.AllowsRequest());
circuitBreaker.MarkFailure();
Assert.Equal(CircuitBreakerState.Open, circuitBreaker.State);
Assert.False(circuitBreaker.AllowsRequest());
Thread.Sleep(config.SleepWindow.Add(TimeSpan.FromMilliseconds(1)));
Assert.Equal(CircuitBreakerState.Open, circuitBreaker.State);
Assert.True(circuitBreaker.AllowsRequest());
}
public void When_Threshhold_Exceeded_Circuit_Opens()
{
var circuitBreaker = new CircuitBreaker(new CircuitBreakerConfiguration
{
ErrorThresholdPercentage = 80
});
for (var i = 0; i < 100; i++)
{
circuitBreaker.MarkSuccess();
Assert.Equal(CircuitBreakerState.Closed, circuitBreaker.State);
Assert.True(circuitBreaker.AllowsRequest());
}
for (var i = 0; i < 399; i++)
{
circuitBreaker.MarkFailure();
Assert.True(circuitBreaker.AllowsRequest());
Assert.Equal(CircuitBreakerState.Closed, circuitBreaker.State);
}
circuitBreaker.MarkFailure();
Assert.False(circuitBreaker.AllowsRequest());
Assert.Equal(CircuitBreakerState.Open, circuitBreaker.State);
}
public void When_Closed_Reset_To_Closed()
{
var circuitBreaker = new CircuitBreaker();
Assert.Equal(CircuitBreakerState.Closed, circuitBreaker.State);
Assert.True(circuitBreaker.AllowsRequest());
circuitBreaker.Reset();
Assert.Equal(CircuitBreakerState.Closed, circuitBreaker.State);
Assert.True(circuitBreaker.AllowsRequest());
}
public void When_Volume_Exceeded_Circuit_Opens()
{
var config = new CircuitBreakerConfiguration();
var circuitBreaker = new CircuitBreaker(config);
for (var i = 0; i < config.VolumeThreshold - 1; i++)
{
circuitBreaker.MarkFailure();
Assert.Equal(CircuitBreakerState.Closed, circuitBreaker.State);
Assert.True(circuitBreaker.AllowsRequest());
}
circuitBreaker.MarkFailure();
Assert.False(circuitBreaker.AllowsRequest());
Assert.Equal(CircuitBreakerState.Open, circuitBreaker.State);
}
public void When_Created_AllowAttempts_IsTrue()
{
var circuitBreaker = new CircuitBreaker();
Assert.True(circuitBreaker.AllowsRequest());
Assert.Equal(CircuitBreakerState.Closed, circuitBreaker.State);
}
public void When_State_is_Open_Can_Reset()
{
var config = new CircuitBreakerConfiguration
{
VolumeThreshold = 1
};
var circuitBreaker = new CircuitBreaker(config);
circuitBreaker.MarkFailure();
Assert.Equal(CircuitBreakerState.Open, circuitBreaker.State);
Assert.False(circuitBreaker.AllowsRequest());
circuitBreaker.Reset();
Assert.Equal(CircuitBreakerState.Closed, circuitBreaker.State);
Assert.True(circuitBreaker.AllowsRequest());
}
public void When_RollingWindow_Completes_State_Is_Closed()
{
var config = new CircuitBreakerConfiguration
{
VolumeThreshold = 2,
RollingWindow = TimeSpan.FromMilliseconds(100)
};
var circuitBreaker = new CircuitBreaker(config);
circuitBreaker.MarkFailure();
Assert.Equal(CircuitBreakerState.Closed, circuitBreaker.State);
Assert.True(circuitBreaker.AllowsRequest());
Thread.Sleep(config.SleepWindow.Add(TimeSpan.FromMilliseconds(1)));
circuitBreaker.MarkFailure();
Assert.Equal(CircuitBreakerState.Closed, circuitBreaker.State);
Assert.True(circuitBreaker.AllowsRequest());
}
public void When_Reset_State_Is_Closed()
{
var circuitBreaker = new CircuitBreaker();
for (var i = 0; i < 55; i++)
{
circuitBreaker.MarkFailure();
}
circuitBreaker.Reset();
Assert.True(circuitBreaker.AllowsRequest());
Assert.Equal(CircuitBreakerState.Closed, circuitBreaker.State);
}
public void When_Track_State_Is_HalfOpen()
{
var circuitBreaker = new CircuitBreaker();
for (var i = 0; i < 55; i++)
{
circuitBreaker.MarkFailure();
}
circuitBreaker.Track();
Assert.False(circuitBreaker.AllowsRequest());
Assert.Equal(CircuitBreakerState.HalfOpen, circuitBreaker.State);
}
public void When_HalfOpen_And_MarkSuccess_Called_State_Is_Closed()
{
var circuitBreaker = new CircuitBreaker();
for (var i = 0; i < 55; i++)
{
circuitBreaker.MarkFailure();
}
circuitBreaker.Track();
//send off canary and if it returns successfully
circuitBreaker.MarkSuccess();
Assert.True(circuitBreaker.AllowsRequest());
Assert.Equal(CircuitBreakerState.Closed, circuitBreaker.State);
}
public void When_Window_Is_Expired_State_Is_Reset()
{
var config = new CircuitBreakerConfiguration
{
RollingWindow = TimeSpan.FromSeconds(10)
};
var circuitBreaker = new CircuitBreaker(config);
for (var i = 0; i < 22; i++)
{
circuitBreaker.MarkFailure();
if (i == 20)
{
Thread.Sleep(config.RollingWindow);
}
}
circuitBreaker.MarkSuccess();
Assert.True(circuitBreaker.AllowsRequest());
Assert.Equal(CircuitBreakerState.Closed, circuitBreaker.State);
}
