internal void KeepAlive()
{
if (!(physical?.IsIdle() ?? false))
{
return; // don't pile on if already doing something
}
var commandMap = Multiplexer.CommandMap;
Message msg = null;
var features = ServerEndPoint.GetFeatures();
switch (ConnectionType)
{
case ConnectionType.Interactive:
msg = ServerEndPoint.GetTracerMessage(false);
msg.SetSource(ResultProcessor.Tracer, null);
break;
case ConnectionType.Subscription:
if (commandMap.IsAvailable(RedisCommand.PING) && features.PingOnSubscriber)
{
msg = Message.Create(-1, CommandFlags.FireAndForget, RedisCommand.PING);
msg.SetSource(ResultProcessor.Tracer, null);
}
else if (commandMap.IsAvailable(RedisCommand.UNSUBSCRIBE))
{
msg = Message.Create(-1, CommandFlags.FireAndForget, RedisCommand.UNSUBSCRIBE,
(RedisChannel)Multiplexer.UniqueId);
msg.SetSource(ResultProcessor.TrackSubscriptions, null);
}
break;
}
if (msg != null)
{
msg.SetInternalCall();
Multiplexer.Trace("Enqueue: " + msg);
Multiplexer.OnInfoMessage($"heartbeat ({physical?.LastWriteSecondsAgo}s >= {ServerEndPoint?.WriteEverySeconds}s, {physical?.GetSentAwaitingResponseCount()} waiting) '{msg.CommandAndKey}' on '{PhysicalName}' (v{features.Version})");
physical?.UpdateLastWriteTime(); // pre-emptively
#pragma warning disable CS0618
var result = TryWriteSync(msg, ServerEndPoint.IsSlave);
#pragma warning restore CS0618
if (result != WriteResult.Success)
{
var ex = Multiplexer.GetException(result, msg, ServerEndPoint);
OnInternalError(ex);
}
}
}
