public override bool Execute(NotificationRequest request)
{
lock (History)
{
var key = GetKey(request);
AlertHistory alertHistory;
if (!History.ContainsKey(key))
{
alertHistory = new AlertHistory { Received = DateTime.UtcNow };
HandleFirstAlert(request, alertHistory);
return true;
}
// has count change from last?
alertHistory = History[key];
if (!HasNotificationChanged(request, alertHistory))
{
Logger.Debug("ResultCount for Check '{0}' is unchanged, not publishing", request.CheckId);
return false;
}
HandleStateChange(request, alertHistory);
return true;
}
}
public override bool Execute(NotificationRequest request)
{
lock (History)
{
var key = GetKey(request);
AlertHistory alertHistory;
if (!History.ContainsKey(key))
{
alertHistory = new AlertHistory
{
Result = request.Notification.Result,
Received = DateTime.UtcNow
};
var result = request.Notification.Result.GetValueOrDefault(true);
if (!result)
alertHistory.FailuresSinceLastSuccess++;
HandleFirstAlert(request, alertHistory);
// only publish if initial failure result
return !result;
}
// has state change from last?
alertHistory = History[key];
if (!HasStateChanged(request, alertHistory))
{
Logger.Debug("State for Check '{0}' is unchanged, not publishing", request.CheckId);
return false;
}
HandleStateChange(request, alertHistory);
return true;
}
}
protected override bool HasStateChanged(NotificationRequest request, AlertHistory alertHistory)
{
var changed = alertHistory.Result != request.Notification.Result;
if (changed)
{
if (alertHistory.Result.GetValueOrDefault(false))
{
// flipped to success from failure
alertHistory.FailuresSinceLastSuccess = 0;
}
Logger.Debug("{0} state changed!", request.CheckId);
return true;
}
// not changed - do we need to consider frequency of our nagging?
if (alertHistory.Result.HasValue)
{
if (alertHistory.Result.Value)
{
// stream of success messages
Logger.Debug("{0} result:={1} (success stream)", request.CheckId, alertHistory.Result.Value);
return false;
}
// stream of failures...check frequency
alertHistory.FailuresSinceLastSuccess++;
var minimumMinutesSeparation = FindAlertSeparation(alertHistory.FailuresSinceLastSuccess);
var minutesDiff = DateTime.UtcNow.Subtract(alertHistory.Received).TotalMinutes;
Logger.Debug("{0} failures;={1}, separation:={2}, lastdiff:={3}", request.CheckId, alertHistory.FailuresSinceLastSuccess, minimumMinutesSeparation, minutesDiff);
return (minutesDiff >= minimumMinutesSeparation);
}
return true;
}
protected virtual bool HasNotificationChanged(NotificationRequest request, AlertHistory alertHistory)
{
return !alertHistory.ResultCount.GetValueOrDefault(0).Equals(request.Notification.ResultCount.GetValueOrDefault(0));
}
protected virtual void HandleStateChange(NotificationRequest request, AlertHistory alertHistory)
{
alertHistory.InjectFrom<LoopValueInjection>(request.Notification);
alertHistory.Received = DateTime.UtcNow;
}
protected virtual void HandleFirstAlert(NotificationRequest request, AlertHistory alertHistory)
{
alertHistory.InjectFrom<LoopValueInjection>(request.Notification);
History.Add(GetKey(request), alertHistory);
}
protected virtual bool HasStateChanged(NotificationRequest request, AlertHistory alertHistory)
{
return alertHistory.Result != request.Notification.Result;
}
protected virtual void HandleStateChange(NotificationRequest request, AlertHistory alertHistory)
{
alertHistory.Result = request.Notification.Result;
alertHistory.Received = DateTime.UtcNow;
}
protected virtual void HandleFirstAlert(NotificationRequest request, AlertHistory alertHistory)
{
History.Add(GetKey(request), alertHistory);
}