/// <summary>
/// Queue initial heartbeats to active servers
/// </summary>
public void QueueInitialHeartbeats()
{
DateTime Now = DateTime.UtcNow;
uint HeartbeatsStarted = 0;
lock (ActiveServerTable)
{
foreach (var Pair in ActiveServerTable)
{
NWGameServer Server = Pair.Value;
lock (Server)
{
if (!Server.Online)
{
continue;
}
Server.InitialHeartbeat = true;
Server.StartHeartbeat();
HeartbeatsStarted += 1;
}
}
}
Logger.Log(LogLevel.Normal, "NWServerTracker.QueueInitialHeartbeats(): Queued {0} initial server heartbeat requests.", HeartbeatsStarted);
PendingGameServersSweepTimer.Start();
ScavengerSweepTimer.Start();
BlacklistSweepTimer.Start();
}
/// <summary>
/// This method disables future heartbeats and flushes any servers that
/// may be in the heartbeat path out of that code path before further
/// forward progress is allowed.
/// </summary>
public void DrainHeartbeats()
{
//
// Prevent new requestors from spinning up new heartbeat requests.
//
HeartbeatsEnabled = false;
//
// Flush any in-flight requestors out of the heartbeat path by
// ensuring that they have released synchronization.
//
Monitor.Enter(HeartbeatLock);
Monitor.Exit(HeartbeatLock);
//
// Stop all of the active timers. New timers that have elapsed
// will have already completed starting the timer again or will now
// observe that future timer restarts are already forbidden.
//
PendingGameServersSweepTimer.Stop();
ScavengerSweepTimer.Stop();
BlacklistSweepTimer.Stop();
}
/// <summary>
/// This timer callback runs when the scavenge sweep timer elapses.
/// Its purpose is to cycle through offline game_servers records in the
/// database, which have had a heartbeat more recent than
/// ScavengerTimeSpan since the current time. Such servers are then
/// re-pinged in a low frequency interval so as to allow servers that
/// had gone offline for a long period of time (but had been returned
/// to service afterwards) to be automatically re-listed eventually.
/// </summary>
/// <param name="sender">Unused.</param>
/// <param name="e">Unused.</param>
private void ScavengerSweepTimer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
{
try
{
bool Processed = false;
DateTime Now = DateTime.UtcNow;
string Query = String.Format(
@"SELECT `game_server_id`,
`server_address`
FROM `game_servers`
WHERE `product_id` = {0}
AND `game_server_id` > {1}
AND `online` = false
AND `last_heartbeat` >= '{2}'
GROUP BY `game_server_id`
ORDER BY `game_server_id`
LIMIT 50",
MasterServer.ProductID,
ScavengeServerId,
MasterServer.DateToSQLDate(Now.Subtract(ScavengerTimeSpan)));
//
// Examine each server record returned and, if the server is
// still offline, enqueue a ping to it. Advance the iterator
// to the next server as each server is processed.
//
using (MySqlDataReader Reader = MasterServer.ExecuteQuery(Query))
{
while (Reader.Read())
{
uint ServerId = Reader.GetUInt32(0);
IPEndPoint ServerAddress = ConvertServerHostnameToIPEndPoint(Reader.GetString(1));
if (ServerId > ScavengeServerId)
{
ScavengeServerId = ServerId;
}
Processed = true;
if (ServerAddress == null)
{
continue;
}
NWGameServer Server = LookupServerByAddress(ServerAddress, false);
if (Server == null || Server.Online == false)
{
MasterServer.SendServerInfoRequest(ServerAddress);
}
}
}
//
// If no servers were processed, then the end of the iterator
// list must have been reached. Re-start the sweep cycle at
// the beginning next time.
//
if (Processed == false)
{
ScavengeServerId = 0;
}
}
catch (Exception ex)
{
Logger.Log(LogLevel.Error, "NWServerTracker.ScavengeSweepTimer_Elapsed(): Excepton processing scavenge server list: {0}", ex);
}
lock (HeartbeatLock)
{
if (!HeartbeatsEnabled)
{
return;
}
ScavengerSweepTimer.Start();
}
}
