public HealthMonitor(IDnsServer dnsServer, IPAddress address, HealthCheck healthCheck, Uri healthCheckUrl)
{
_dnsServer = dnsServer;
_address = address;
_healthCheck = healthCheck;
_healthCheckTimer = new Timer(async delegate(object state)
{
try
{
if (_healthCheck is null)
{
_lastHealthCheckResponse = null;
}
else
{
HealthCheckResponse healthCheckResponse = await _healthCheck.IsHealthyAsync(_address, healthCheckUrl);
bool statusChanged = false;
bool maintenance = false;
if (_lastHealthCheckResponse is null)
{
switch (healthCheckResponse.Status)
{
case HealthStatus.Failed:
statusChanged = true;
break;
case HealthStatus.Maintenance:
statusChanged = true;
maintenance = true;
break;
}
}
else
{
if (_lastHealthCheckResponse.Status != healthCheckResponse.Status)
{
statusChanged = true;
if ((_lastHealthCheckResponse.Status == HealthStatus.Maintenance) || (healthCheckResponse.Status == HealthStatus.Maintenance))
{
maintenance = true;
}
}
}
if (statusChanged)
{
switch (healthCheckResponse.Status)
{
case HealthStatus.Failed:
_dnsServer.WriteLog("ALERT! Address [" + _address.ToString() + "] status is FAILED based on '" + _healthCheck.Name + "' health check. The failure reason is: " + healthCheckResponse.FailureReason);
break;
default:
_dnsServer.WriteLog("ALERT! Address [" + _address.ToString() + "] status is " + healthCheckResponse.Status.ToString().ToUpper() + " based on '" + _healthCheck.Name + "' health check.");
break;
}
if (healthCheckResponse.Exception is not null)
{
_dnsServer.WriteLog(healthCheckResponse.Exception);
}
if (!maintenance)
{
//avoid sending email alerts when switching from or to maintenance
EmailAlert emailAlert = _healthCheck.EmailAlert;
if (emailAlert is not null)
{
_ = emailAlert.SendAlertAsync(_address, _healthCheck.Name, healthCheckResponse);
}
}
WebHook webHook = _healthCheck.WebHook;
if (webHook is not null)
{
_ = webHook.CallAsync(_address, _healthCheck.Name, healthCheckResponse);
}
}
_lastHealthCheckResponse = healthCheckResponse;
}
}
catch (Exception ex)
{
_dnsServer.WriteLog(ex);
if (_lastHealthCheckResponse is null)
{
EmailAlert emailAlert = _healthCheck.EmailAlert;
if (emailAlert is not null)
{
_ = emailAlert.SendAlertAsync(_address, _healthCheck.Name, ex);
}
WebHook webHook = _healthCheck.WebHook;
if (webHook is not null)
{
_ = webHook.CallAsync(_address, _healthCheck.Name, ex);
}
_lastHealthCheckResponse = new HealthCheckResponse(HealthStatus.Failed, ex.ToString(), ex);
}
else
{
_lastHealthCheckResponse = null;
}
}
finally
{
if (!_disposed && (_healthCheck is not null))
{
_healthCheckTimer.Change(_healthCheck.Interval, Timeout.Infinite);
}
}
}, null, Timeout.Infinite, Timeout.Infinite);
_healthCheckTimer.Change(HEALTH_CHECK_TIMER_INITIAL_INTERVAL, Timeout.Infinite);
}
public HealthMonitor(IDnsServer dnsServer, IPAddress address, HealthCheck healthCheck)
{
_dnsServer = dnsServer;
_address = address;
_healthCheck = healthCheck;
_healthCheckTimer = new Timer(async delegate(object state)
{
try
{
if (_healthCheck is null)
{
_healthCheckStatus = null;
}
else
{
HealthCheckStatus healthCheckStatus = await _healthCheck.IsHealthyAsync(_address);
bool sendAlert = false;
if (_healthCheckStatus is null)
{
if (!healthCheckStatus.IsHealthy)
{
sendAlert = true;
}
}
else
{
if (_healthCheckStatus.IsHealthy != healthCheckStatus.IsHealthy)
{
sendAlert = true;
}
else if (_healthCheckStatus.FailureReason != healthCheckStatus.FailureReason)
{
sendAlert = true;
}
}
if (sendAlert)
{
EmailAlert emailAlert = _healthCheck.EmailAlert;
if (emailAlert is not null)
{
_ = emailAlert.SendAlertAsync(_address, _healthCheck.Name, healthCheckStatus);
}
WebHook webHook = _healthCheck.WebHook;
if (webHook is not null)
{
_ = webHook.CallAsync(_address, _healthCheck.Name, healthCheckStatus);
}
}
_healthCheckStatus = healthCheckStatus;
}
}
catch (Exception ex)
{
_dnsServer.WriteLog(ex);
if (_healthCheckStatus is null)
{
EmailAlert emailAlert = _healthCheck.EmailAlert;
if (emailAlert is not null)
{
_ = emailAlert.SendAlertAsync(_address, _healthCheck.Name, ex);
}
WebHook webHook = _healthCheck.WebHook;
if (webHook is not null)
{
_ = webHook.CallAsync(_address, _healthCheck.Name, ex);
}
_healthCheckStatus = new HealthCheckStatus(false, ex.ToString());
}
else
{
_healthCheckStatus = null;
}
}
finally
{
if (!_disposed && (_healthCheck is not null))
{
_healthCheckTimer.Change(_healthCheck.Interval, Timeout.Infinite);
}
}
}, null, Timeout.Infinite, Timeout.Infinite);
_healthCheckTimer.Change(0, Timeout.Infinite);
}
