public void Should_Retry_Once_And_Interrupt_The_Attempt_Due_To_The_Retries_Exceeds_The_Timeout_And_Raises_A_TimeoutRejectedException()
{
var expectedRetries = 1;
var expectedTimeout = GetExpectedTimeout(5);
var builder = new SqlPolicyBuilder();
var resilientAsyncPolicy = builder
.UseAsyncExecutor()
.WithDefaultPolicies()
.Build();
var watch = Stopwatch.StartNew();
var ex = Assert.ThrowsAsync <TimeoutRejectedException>(async() =>
{
await resilientAsyncPolicy.ExecuteAsync(async() =>
{
await DoSomethingAsync(45000);
});
});
watch.Stop();
var currentTime = TimeSpan.FromMilliseconds(watch.ElapsedMilliseconds).TotalSeconds;
Assert.IsInstanceOf <TimeoutRejectedException>(ex);
Assert.AreEqual(expectedTimeout.TotalSeconds, Math.Round(currentTime));
}
public static IServiceCollection AddResilientStrategies(this IServiceCollection services, IConfiguration configuration)
{
// Resilient SQL Executor configuration.
services.AddSingleton <IPolicyAsyncExecutor>(sp =>
{
var sqlPolicyBuilder = new SqlPolicyBuilder();
return(sqlPolicyBuilder
.UseAsyncExecutor()
.WithDefaultPolicies()
.Build());
});
// Create (and register with DI) a policy registry containing some policies we want to use.
var policyRegistry = services.AddPolicyRegistry();
policyRegistry[HttpResiliencePolicy] = GetResiliencePolicy(configuration);
// Resilient Http Invoker onfiguration.
// Register a typed client via HttpClientFactory, set to use the policy we placed in the policy registry.
services.AddHttpClient <ResilientHttpClient>(client =>
{
client.Timeout = TimeSpan.FromSeconds(50);
}).AddPolicyHandlerFromRegistry(HttpResiliencePolicy);
return(services);
}
public async Task Should_Break_The_Circuit_Across_Requests_And_Fail_Faster_Then_Wait_For_The_Break_And_Try_Again_Then_Does_Not_Raise_An_Exception()
{
var builderFirstRequest = new SqlPolicyBuilder();
var resilientAsyncPolicyFirstRequest = builderFirstRequest
.UseAsyncExecutorWithSharedPolicies()
.WithDefaultPolicies()
.Build();
var exFirstAttempt = Assert.ThrowsAsync <BrokenCircuitException>(async() =>
{
await resilientAsyncPolicyFirstRequest.ExecuteAsync(async() =>
{
// will break the circuit since throws 3 times in a row the same exception
await DoSomethingToBreakTheCircuitAndContinueAsync();
});
});
// simulates a different request
var builderSecondRequest = new SqlPolicyBuilder();
var resilientAsyncPolicySecondRequest = builderSecondRequest
.UseAsyncExecutorWithSharedPolicies()
.WithDefaultPolicies()
.Build();
var watch2 = Stopwatch.StartNew();
var exSecondAttempt = Assert.ThrowsAsync <BrokenCircuitException>(async() =>
{
await resilientAsyncPolicySecondRequest.ExecuteAsync(async() =>
{
// will fail immediately
await DoSomethingToBreakTheCircuitAndContinueAsync();
});
});
watch2.Stop();
// await the break time
await Task.Delay(TimeSpan.FromSeconds(30));
// simulates a different request
var builderThirdRequest = new SqlPolicyBuilder();
var resilientAsyncPolicyThirdRequest = builderThirdRequest
.UseAsyncExecutorWithSharedPolicies()
.WithDefaultPolicies()
.Build();
// will executes successfully because the circuit is half-open now
var result = await resilientAsyncPolicyThirdRequest.ExecuteAsync(async() =>
{
await DoSomethingToBreakTheCircuitAndContinueAsync();
return(true);
});
var attemptTimeAfterCircuitBroke = TimeSpan.FromMilliseconds(watch2.ElapsedMilliseconds).Seconds;
Assert.AreEqual(true, result);
Assert.IsInstanceOf <BrokenCircuitException>(exFirstAttempt);
Assert.IsInstanceOf <BrokenCircuitException>(exSecondAttempt);
Assert.AreEqual(0, attemptTimeAfterCircuitBroke);
}
public void Should_Retry_Four_Times_Without_Break_The_Circuit_And_Does_Not_Raise_An_Exception()
{
var expectedRetries = 4;
var expectedTime = GetExpectedDelay(expectedRetries) + GetExpectedExecutionTime(expectedRetries);
var builder = new SqlPolicyBuilder();
var resilientSyncPolicy = builder
.UseSyncExecutor()
.WithDefaultPolicies()
.Build();
var watch = Stopwatch.StartNew();
var result = resilientSyncPolicy.Execute(() =>
{
// won't break the circuit since throws random exceptions.
DoSomethingSync();
return(true);
});
watch.Stop();
var currentTime = TimeSpan.FromMilliseconds(watch.ElapsedMilliseconds).Seconds;
Assert.AreEqual(true, result);
Assert.AreEqual(expectedTime.Seconds, currentTime);
}
public async Task Should_Fallback_After_Circuit_Breaker_Exception()
{
var result = false;
var expectedRetries = 3;
// the limitation with this way to handle a fallback is if we want to return a result we need to handle that result separately from the main method and the fallback method
var builder = new SqlPolicyBuilder();
var resilientAsyncPolicy = builder
.UseAsyncExecutor()
.WithDefaultPolicies()
.WithTransaction()
.WithFallback(async() => result = await DoFallbackAsync())
.Build();
await resilientAsyncPolicy.ExecuteAsync(async() =>
{
await Task.Delay(TimeSpan.FromMilliseconds(500));
++_retriesCounter;
throw TransientExceptions[1];
});
Assert.AreEqual(true, result);
Assert.AreEqual(true, _fallbackExecuted);
Assert.AreEqual(expectedRetries, _retriesCounter);
}
public void Should_Interrupt_Retry_Due_To_Operation_Exceeds_Timeout_Per_Retry()
{
var expectedTime = TimeSpan.FromMilliseconds(300);
var builder = new SqlPolicyBuilder();
var resilientAsyncPolicy = builder
.UseAsyncExecutor()
.WithDefaultPolicies()
.WithTimeoutPerRetry(TimeSpan.FromMilliseconds(300))
.Build();
var watch = new Stopwatch();
var ex = Assert.ThrowsAsync <TimeoutRejectedException>(async() =>
{
await resilientAsyncPolicy.ExecuteAsync(async() =>
{
watch.Start();
await Task.Delay(TimeSpan.FromMilliseconds(400));
});
});
watch.Stop();
Assert.IsInstanceOf <TimeoutRejectedException>(ex);
Assert.IsTrue(watch.ElapsedMilliseconds >= expectedTime.Milliseconds && watch.ElapsedMilliseconds < 350);
}
public async Task Should_Retry_Transaction_Errors_Four_Times_Without_Break_The_Circuit_And_Does_Not_Raise_An_Exception()
{
var expectedRetries = 4;
var expectedTime = GetExpectedDelay(expectedRetries) + GetExpectedExecutionTime(expectedRetries);
var builder = new SqlPolicyBuilder();
var resilientAsyncPolicy = builder
.UseAsyncExecutor()
.WithDefaultPolicies()
.WithTransaction()
.Build();
var watch = Stopwatch.StartNew();
var result = await resilientAsyncPolicy.ExecuteAsync(async() =>
{
await DoSomethingWithTransactionAsync();
return(true);
});
watch.Stop();
var currentTime = TimeSpan.FromMilliseconds(watch.ElapsedMilliseconds).Seconds;
Assert.AreEqual(true, result);
Assert.AreEqual(_threshold, _retriesCounter);
}
public async Task Should_Fallback_After_Timeout_Exception()
{
var result = false;
var expectedRetries = 0;
var expectedTimeout = GetExpectedTimeout(5);
// the limitation with this way to handle a fallback is if we want to return a result we need to handle that result separately from the main method and the fallback method
var builder = new SqlPolicyBuilder();
var resilientAsyncPolicy = builder
.UseAsyncExecutor()
.WithDefaultPolicies()
.WithTransaction()
.WithFallback(async() => result = await DoFallbackAsync())
.Build();
var watch = Stopwatch.StartNew();
await resilientAsyncPolicy.ExecuteAsync(async() =>
{
result = await DoSomethingWithTransactionAsync(120000);
});
watch.Stop();
var currentTime = TimeSpan.FromMilliseconds(watch.ElapsedMilliseconds).Seconds;
Assert.AreEqual(true, result);
Assert.AreEqual(true, _fallbackExecuted);
Assert.AreEqual(expectedRetries, _retriesCounter);
Assert.AreEqual(expectedTimeout.Seconds, currentTime);
}
public void Should_Retry_Transaction_Errors_Three_Times_The_Same_Exception_And_The_Fourth_Attempt_Break_The_Circuit_And_Raise_A_BrokenCircuitException()
{
var expectedRetries = 3;
var expectedTime = GetExpectedDelay(expectedRetries) + GetExpectedExecutionTime(expectedRetries);
var builder = new SqlPolicyBuilder();
var resilientAsyncPolicy = builder
.UseAsyncExecutor()
.WithDefaultPolicies()
.WithTransaction()
.Build();
var watch = Stopwatch.StartNew();
var ex = Assert.ThrowsAsync <BrokenCircuitException>(async() =>
{
await resilientAsyncPolicy.ExecuteAsync(async() =>
{
// will break the circuit since throws 3 times in a row the same exception
await DoSomethingWithTransactionToBreakTheCircuitAsync();
});
});
watch.Stop();
var currentTime = TimeSpan.FromMilliseconds(watch.ElapsedMilliseconds).Seconds;
Assert.IsInstanceOf <BrokenCircuitException>(ex);
Assert.AreEqual(ex.Message, "The circuit is now open and is not allowing calls.");
Assert.AreEqual(expectedTime.Seconds, currentTime);
Assert.AreEqual(expectedRetries, _retriesCounter);
}
public void Should_Do_Not_Retry_Due_To_The_Operation_Exceeds_The_Timeout_And_Raises_A_TimeoutRejectedException()
{
var expectedRetries = 0;
var expectedTimeout = GetExpectedTimeout(5);
var builder = new SqlPolicyBuilder();
var resilientSyncPolicy = builder
.UseSyncExecutor()
.WithDefaultPolicies()
.Build();
var watch = Stopwatch.StartNew();
var ex = Assert.Throws <TimeoutRejectedException>(() =>
{
resilientSyncPolicy.Execute(() =>
{
DoSomethingSync(120000);
});
});
watch.Stop();
var currentTime = TimeSpan.FromMilliseconds(watch.ElapsedMilliseconds).TotalSeconds;
Assert.IsInstanceOf <TimeoutRejectedException>(ex);
Assert.AreEqual(expectedTimeout.TotalSeconds, Math.Round(currentTime));
Assert.AreEqual(expectedRetries, _retriesCounter);
}
public async Task Should_Transaction_Errors_Break_The_Circuit_And_Wait_For_The_Break_And_Try_Again_And_Does_Not_Raise_An_Exception()
{
var expectedRetries = 3;
// 3 retries with exponential back-off + 4 executions (last is the successful one) + circuit break time
var expectedTime = GetExpectedDelay(expectedRetries) + GetExpectedExecutionTime(4) + TimeSpan.FromSeconds(30);
// IMPORTANT NOTE: in a real scenario, this behavior will only happen if we share the same instance of policies among requests.
var builder = new SqlPolicyBuilder();
var resilientAsyncPolicy = builder
.UseAsyncExecutor()
.WithDefaultPolicies()
.WithTransaction()
.Build();
var watch = Stopwatch.StartNew();
var exFirstAttempt = Assert.ThrowsAsync <BrokenCircuitException>(async() =>
{
await resilientAsyncPolicy.ExecuteAsync(async() =>
{
// will break the circuit since throws 3 times in a row the same exception
await DoSomethingWithTransactionToBreakTheCircuitAndContinueAsync();
});
});
var watch2 = Stopwatch.StartNew();
var exSecondAttempt = Assert.ThrowsAsync <BrokenCircuitException>(async() =>
{
await resilientAsyncPolicy.ExecuteAsync(async() =>
{
// will fail immediately
await DoSomethingWithTransactionToBreakTheCircuitAndContinueAsync();
});
});
watch2.Stop();
// await the break time
await Task.Delay(TimeSpan.FromSeconds(30));
// will executes successfully because the circuit is half-open now
var result = await resilientAsyncPolicy.ExecuteAsync(async() =>
{
await DoSomethingWithTransactionToBreakTheCircuitAndContinueAsync();
return(true);
});
watch.Stop();
var currentTime = TimeSpan.FromMilliseconds(watch.ElapsedMilliseconds).Seconds;
var attemptTimeAfterCircuitBroke = TimeSpan.FromMilliseconds(watch2.ElapsedMilliseconds).Seconds;
Assert.AreEqual(true, result);
Assert.IsInstanceOf <BrokenCircuitException>(exFirstAttempt);
Assert.IsInstanceOf <BrokenCircuitException>(exSecondAttempt);
Assert.AreEqual(expectedTime.Seconds, currentTime);
Assert.AreEqual(0, attemptTimeAfterCircuitBroke);
}
public void Should_Fails_Due_To_There_Are_No_Policies()
{
var exception = Assert.Throws <InvalidOperationException>(() =>
{
var builder = new SqlPolicyBuilder();
var resilientAsyncPolicy = builder
.UseAsyncExecutor()
.Build();
});
Assert.IsInstanceOf <InvalidOperationException>(exception);
Assert.AreEqual(exception.Message, "There are no policies to execute.");
}
public void Should_Fails_Due_To_There_Is_TimeOut_Per_Retry_Policy_But_There_Are_NotRetry_Policies()
{
var exception = Assert.Throws <InvalidOperationException>(() =>
{
var builder = new SqlPolicyBuilder();
var resilientAsyncPolicy = builder
.UseAsyncExecutor()
.WithTimeoutPerRetry(TimeSpan.FromSeconds(20))
.Build();
});
Assert.IsInstanceOf <InvalidOperationException>(exception);
Assert.AreEqual(exception.Message, "You're trying to use Timeout per retries but you don't have Retry policies configured.");
}
public void Should_Fails_Due_To_There_Are_Duplicated_Policies()
{
var exception = Assert.Throws <InvalidOperationException>(() =>
{
var builder = new SqlPolicyBuilder();
var resilientAsyncPolicy = builder
.UseAsyncExecutor()
.WithDefaultPolicies()
.WithTransientErrors()
.Build();
});
Assert.IsInstanceOf <InvalidOperationException>(exception);
Assert.AreEqual(exception.Message, "There are duplicated policies. When you use WithDefaultPolicies method, you can't use either WithTransientErrors. WithCircuitBreaker or WithOverallTimeout methods at the same time, because those policies are already included.");
}
public void Should_Retry_Transaction_Errors_Four_Times_Without_Break_The_Circuit_And_Does_Not_Raise_An_Exception()
{
var builder = new SqlPolicyBuilder();
var resilientSyncPolicy = builder
.UseSyncExecutor()
.WithDefaultPolicies()
.WithTransaction()
.Build();
var watch = Stopwatch.StartNew();
var result = resilientSyncPolicy.Execute(() =>
{
DoSomethingWithTransactionSync();
return(true);
});
watch.Stop();
Assert.AreEqual(true, result);
Assert.AreEqual(_threshold, _retriesCounter);
}
public void Should_Interrupt_Retry_Due_To_Operation_Exceeds_Timeout_Per_Retry()
{
var builder = new SqlPolicyBuilder();
var resilientSyncPolicy = builder
.UseSyncExecutor()
.WithDefaultPolicies()
.WithTimeoutPerRetry(TimeSpan.FromMilliseconds(300))
.Build();
var watch = new Stopwatch();
var ex = Assert.Throws <TimeoutRejectedException>(() =>
{
resilientSyncPolicy.Execute(() =>
{
watch.Start();
SystemClock.Sleep(TimeSpan.FromSeconds(3), CancellationToken.None);
});
});
watch.Stop();
Assert.IsInstanceOf <TimeoutRejectedException>(ex);
}
public void Should_Fallback_After_Sql_Exception()
{
var result = false;
// the limitation with this way to handle a fallback is if we want to return a result we need to handle that result separately from the main method and the fallback method
var builder = new SqlPolicyBuilder();
var resilientSyncPolicy = builder
.UseSyncExecutor()
.WithDefaultPolicies()
.WithTransaction()
.WithFallback(() => result = DoFallbackSync())
.Build();
resilientSyncPolicy.Execute(() =>
{
Thread.Sleep(TimeSpan.FromMilliseconds(500));
throw GetRandomException();
});
Assert.AreEqual(true, result);
Assert.AreEqual(true, _fallbackExecuted);
}