protected abstract void LogToDatabase(string strMessage); // Add other parameters later.
private void ReadTargetsFromDatabase()
{
List <Target> lstEnabledTargets = new List <Target>();
MySqlConnection con = DatabaseConnectionProvider.GetMySqlConnection();
// ThAW TO_DO 2009/08/26 : Use a Select command that only selects enabled targets that are associated with enabled accounts.
string strCommandText = Target.SelectAllCommand;
using (MySqlCommand cmd = new MySqlCommand(strCommandText, con))
{
using (MySqlDataReader reader = cmd.ExecuteReader())
{
while (reader.Read())
{
Target target = new Target(reader, false); // Do not close the reader after constructing the object
if (target.Enabled)
{
lstEnabledTargets.Add(target);
}
}
}
}
foreach (Target target in lstEnabledTargets)
{
target.FinishConstruction(con);
m_pqWaitingTargets.Enqueue(target);
LogToConsole(string.Format(@"Constructed and enqueued the enabled target named '{0}'", target.Name));
}
}
public void Run()
{
LogToConsole(@"Flare main loop: start");
lock (this)
{
m_eServiceStatus = FlareServiceStatus.Started;
}
try
{
m_pqWaitingTargets.Clear();
m_qTargetsReadyForTesting.Clear();
ReadTargetsFromDatabase();
MySqlConnection con = DatabaseConnectionProvider.GetMySqlConnection();
m_lstAllContacts = Contact.GetAllContacts(con);
m_dictSystemConfigurationEntries = SystemConfigurationEntry.GetDictionary(con);
if (m_pqWaitingTargets.IsEmpty())
{
LogToConsole(@"Aborting: The priority queue is empty; there are no servers to monitor.");
return;
}
// The main loop begins here.
TimeSpan tsOneSecond = new TimeSpan(0, 0, 1);
TimeSpan tsLoopPeriod = new TimeSpan(0, 0, 1);
bool bLimitNumberOfMainLoopIterations = (NumberOfMainLoopIterations > 0);
LogToConsole(@"Starting the main loop...");
for (int nMainLoopIterationNumber = 0;
!bLimitNumberOfMainLoopIterations || nMainLoopIterationNumber < NumberOfMainLoopIterations;
++nMainLoopIterationNumber)
{
DateTime dtNow = DateTime.UtcNow;
LogToConsole(string.Format(@"It is now {0}.", dtNow.ToLongTimeString()));
if (m_pqWaitingTargets.IsEmpty())
{
LogToConsole(@"The priority queue is empty; sleeping for one second.");
System.Threading.Thread.Sleep(tsOneSecond);
continue;
}
Target targetHead = m_pqWaitingTargets.Peek();
LogToConsole(string.Format(@"The target at the head of the queue ('{0}') is due to be tested at {1}.",
targetHead.Name, targetHead.DateTimeOfNextMonitor.ToLongTimeString()));
if (dtNow < targetHead.DateTimeOfNextMonitor)
{
TimeSpan tsDifference = targetHead.DateTimeOfNextMonitor - dtNow;
TimeSpan tsTimeSpanToSleep = (tsDifference < tsLoopPeriod) ? tsDifference : tsLoopPeriod;
LogToConsole(string.Format(@"It is not yet time to test the target at the head of the queue. Sleeping for {0} seconds and {1} milliseconds...",
tsTimeSpanToSleep.Seconds, tsTimeSpanToSleep.Milliseconds));
System.Threading.Thread.Sleep(tsTimeSpanToSleep);
continue;
}
lock (m_qTargetsReadyForTesting)
{
m_qTargetsReadyForTesting.Enqueue(m_pqWaitingTargets.Dequeue());
}
#if MULTITHREAD_TARGET_TESTING
// Note: There is also a delegate named ParameterizedThreadStart; perhaps it may be useful
// in allowing us to pass a TargetInfo object as a parameter, thus avoiding the m_qTargetsReadyForTesting queue.
Thread thread = new Thread(new ThreadStart(ThreadMain_TestTarget));
thread.Start();
#else
ThreadMain_TestTarget();
#endif
lock (this)
{
if (m_eServiceStatus == FlareServiceStatus.StopRequested)
{
break;
}
}
}
}
catch (Exception ex)
{
LogToConsole(string.Format(@"{0} caught: {1}", ex.GetType().FullName, ex.Message));
}
lock (this)
{
m_eServiceStatus = FlareServiceStatus.Stopped;
}
LogToConsole(@"Flare main loop: end");
}
private void ThreadMain_TestTarget()
{
LogToConsole(@"**** Thread starting ****");
Target target = null;
lock (m_qTargetsReadyForTesting)
{
if (m_qTargetsReadyForTesting.Count <= 0)
{
// Throw an exception when we attempt to Dequeue() ?
return;
}
target = m_qTargetsReadyForTesting.Dequeue();
}
LogToConsole(string.Format(@"Testing the target {0} (at {1}).", target.Name, target.URL));
// In a separate thread:
// - HTTP Post to the target
// - Handle any errors (by logging to a database and sending e-mail(s))
// - Re-enqueue the TargetInfo object while the priority queue is locked.
TargetLogRecord tlr = null;
switch (target.MonitorType)
{
case MonitorType.eHTTPGet:
tlr = GetFromTarget(target);
break;
case MonitorType.eHTTPPost:
tlr = PostToTarget(target);
break;
case MonitorType.ePing:
tlr = PingTarget(target);
break;
// Default case: Throw an exception?
}
if (tlr != null)
{
MySqlConnection con = DatabaseConnectionProvider.GetMySqlConnection();
tlr.Insert(con);
target.UpdateLastTargetLogID(tlr.LogID, con);
if (tlr.Status == TargetLogRecordStatus.Fail)
{
// Send an e-mail to each of the target's account's contacts.
SendFailureNotificationEmails(target, tlr);
}
}
//target.LastMonitoredAt = DateTime.UtcNow;
target.UpdateLastMonitoredAt(DateTime.UtcNow, DatabaseConnectionProvider.GetMySqlConnection());
target.DateTimeOfNextMonitor = target.LastMonitoredAt.Value + target.MonitorIntervalAsTimeSpan; // or += target.MonitorIntervalAsTimeSpan;
// Update the target's LastMonitoredAt in the database
m_pqWaitingTargets.Enqueue(target);
LogToConsole(string.Format(@"The target {0} has been dequeued, bumped, and re-enqueued.", target.Name));
LogToConsole(@"**** Thread ending ****");
}