static void Main(string[] args)
{
FileTarget wrappedTarget = new FileTarget();
wrappedTarget.FileName = "${basedir}/file.txt";
RetryingTargetWrapper target = new RetryingTargetWrapper();
target.WrappedTarget = wrappedTarget;
target.RetryCount = 3;
target.RetryDelayMilliseconds = 1000;
NLog.Config.SimpleConfigurator.ConfigureForTargetLogging(target, LogLevel.Debug);
Logger logger = LogManager.GetLogger("Example");
logger.Debug("log message");
}
public void RetryingTargetWrapperTest1()
{
var target = new MyTarget();
var wrapper = new RetryingTargetWrapper()
{
WrappedTarget = target,
RetryCount = 10,
RetryDelayMilliseconds = 1,
};
((ISupportsInitialize)wrapper).Initialize();
((ISupportsInitialize)target).Initialize();
var events = new LogEventInfo[]
{
new LogEventInfo(LogLevel.Debug, "Logger1", "Hello"),
new LogEventInfo(LogLevel.Info, "Logger1", "Hello"),
new LogEventInfo(LogLevel.Info, "Logger2", "Hello"),
};
var exceptions = new List<Exception>();
var continuations = new AsyncContinuation[events.Length];
for (int i = 0; i < continuations.Length; ++i)
{
continuations[i] = exceptions.Add;
}
wrapper.WriteLogEvents(events, continuations);
// make sure all events went through
Assert.AreEqual(3, target.Events.Count);
Assert.AreSame(events[0], target.Events[0]);
Assert.AreSame(events[1], target.Events[1]);
Assert.AreSame(events[2], target.Events[2]);
Assert.AreEqual(continuations.Length, exceptions.Count, "Some continuations were not invoked.");
// make sure there were no exception
foreach (var ex in exceptions)
{
Assert.IsNull(ex);
}
}
public void RetryingTargetWrapperTest1()
{
var target = new MyTarget();
var wrapper = new RetryingTargetWrapper()
{
WrappedTarget = target,
RetryCount = 10,
RetryDelayMilliseconds = 1,
};
wrapper.Initialize(null);
target.Initialize(null);
var exceptions = new List<Exception>();
var events = new []
{
new LogEventInfo(LogLevel.Debug, "Logger1", "Hello").WithContinuation(exceptions.Add),
new LogEventInfo(LogLevel.Info, "Logger1", "Hello").WithContinuation(exceptions.Add),
new LogEventInfo(LogLevel.Info, "Logger2", "Hello").WithContinuation(exceptions.Add),
};
wrapper.WriteAsyncLogEvents(events);
// make sure all events went through
Assert.AreEqual(3, target.Events.Count);
Assert.AreSame(events[0].LogEvent, target.Events[0]);
Assert.AreSame(events[1].LogEvent, target.Events[1]);
Assert.AreSame(events[2].LogEvent, target.Events[2]);
Assert.AreEqual(events.Length, exceptions.Count, "Some continuations were not invoked.");
// make sure there were no exception
foreach (var ex in exceptions)
{
Assert.IsNull(ex);
}
}
public void RetryingTargetWrapperTest2()
{
var target = new MyTarget()
{
ThrowExceptions = 6,
};
var wrapper = new RetryingTargetWrapper()
{
WrappedTarget = target,
RetryCount = 4,
RetryDelayMilliseconds = 1,
};
wrapper.Initialize(null);
target.Initialize(null);
var exceptions = new List<Exception>();
var events = new []
{
new LogEventInfo(LogLevel.Debug, "Logger1", "Hello").WithContinuation(exceptions.Add),
new LogEventInfo(LogLevel.Info, "Logger1", "Hello").WithContinuation(exceptions.Add),
new LogEventInfo(LogLevel.Info, "Logger2", "Hello").WithContinuation(exceptions.Add),
};
var internalLogOutput = RunAndCaptureInternalLog(() => wrapper.WriteAsyncLogEvents(events), LogLevel.Trace);
string expectedLogOutput = @"Warn Error while writing to 'MyTarget': System.InvalidOperationException: Some exception has ocurred.. Try 1/4
Warn Error while writing to 'MyTarget': System.InvalidOperationException: Some exception has ocurred.. Try 2/4
Warn Error while writing to 'MyTarget': System.InvalidOperationException: Some exception has ocurred.. Try 3/4
Warn Error while writing to 'MyTarget': System.InvalidOperationException: Some exception has ocurred.. Try 4/4
Warn Too many retries. Aborting.
Warn Error while writing to 'MyTarget': System.InvalidOperationException: Some exception has ocurred.. Try 1/4
Warn Error while writing to 'MyTarget': System.InvalidOperationException: Some exception has ocurred.. Try 2/4
";
Assert.AreEqual(expectedLogOutput, internalLogOutput);
// first event does not get to wrapped target because of too many attempts.
// second event gets there in 3rd retry
// and third event gets there immediately
Assert.AreEqual(2, target.Events.Count);
Assert.AreSame(events[1].LogEvent, target.Events[0]);
Assert.AreSame(events[2].LogEvent, target.Events[1]);
Assert.AreEqual(events.Length, exceptions.Count, "Some continuations were not invoked.");
Assert.IsNotNull(exceptions[0]);
Assert.AreEqual("Some exception has ocurred.", exceptions[0].Message);
Assert.IsNull(exceptions[1]);
Assert.IsNull(exceptions[2]);
}
private Target ConfigureSecurityActionTarget()
{
// Create database target
DatabaseTarget eventLogDatabaseTarget = ConfigureSecurityActionDatabaseTarget();
RetryingTargetWrapper retryTarget = new RetryingTargetWrapper(eventLogDatabaseTarget, 5, 1000);
LogManager.Configuration.AddTarget("FrameworkLoggingSecurityAction", retryTarget);
return retryTarget;
}
private void ConfigureDefaultTarget()
{
const int RetryCount = 2;
const int RetryIntervalMs = 500;
// Create database target
DatabaseTarget eventLogDatabaseTarget = ConfigureDatabaseTarget();
RetryingTargetWrapper retryTarget = new RetryingTargetWrapper(eventLogDatabaseTarget, RetryCount, RetryIntervalMs);
// Create file target
FileTarget fileTarget = ConfigureFileTarget();
// Create Event Log target
EventLogTarget applicationEventLogTarget = ConfigureEventLogTarget(base._applicationName);
// Create fallback group target - database target first, then Event Log target
FallbackGroupTarget fallbackTarget = new FallbackGroupTarget(retryTarget, fileTarget, applicationEventLogTarget);
// With ReturnToFirstOnSuccess true, when the primary target fails and the secondary
// succeeds, NLog will switch back to the primary for the next write, which is what we
// want. With the default of false, if the primary fails once, NLog stays on the secondary
// for the life of the AppDomain -- i.e. only Event Log and no more database.
fallbackTarget.ReturnToFirstOnSuccess = true;
AsyncTargetWrapper asyncFallbackTarget = new AsyncTargetWrapper(fallbackTarget);
asyncFallbackTarget.BatchSize = 200;
asyncFallbackTarget.QueueLimit = 5000;
LogManager.Configuration.AddTarget("FrameworkLoggingDefault", asyncFallbackTarget);
}
