Persistant Random Lag

[Techron]

Is any one else experiencing random lags? They are hard to predict except that while engaged in combat, the hits stop registering. At that time, I try to back-off but it is usually too late. When I open the debugger (F10), my ping is 90 ms. I'm running ManaPlus 1.3.3.17 on a Ubuntu 12.04 LTS, 1 Gig of ram on a Dell Latitude D520 w/ dual core Intel 1.83GHz and 50 Gig hard drive. I am on a wireless connection at 54 Mb/s. I can plug into a 10/100 connection if that data is desired.

Techron

[Nard]

Same here, similar config, 100Mb ethernet, 10/100 adsl, average mannaplus ping 200 ms :/

[AnonDuck]

The "random" lag spikes are actually the map server compressing it's log files periodically. It doesn't do this in the background for some reason so all clients have to wait for the operation to complete. This has been recently fixed in the code and is awaiting a server restart for the fix to be applied. We are also actively working on finding other similar problems and fixing them.

As far as persistent non-spiking latency, that's just the speed of light in action. The server is no longer located in Europe and therefore European users get the type of ping times North/South American users used to. Unfortunately there isn't much do be done about this. The server has the best connectivity to Europe that the internet can provide.. the rest is just physics.

[Big Crunch]

I dont believe in physics. Its probably just God deeming these people as unacceptable to play The Mana World.

[Crush]

As far as persistent non-spiking latency, that's just the speed of light in action. The server is no longer located in Europe and therefore European users get the type of ping times North/South American users used to. Unfortunately there isn't much do be done about this.

Let's move the server to the Azores - same latency for everyone

[Big Crunch]

As far as persistent non-spiking latency, that's just the speed of light in action. The server is no longer located in Europe and therefore European users get the type of ping times North/South American users used to. Unfortunately there isn't much do be done about this.

Let's move the server to the Azores - same latency for everyone

or the southpole. Although we would have to find a Canadian to stay there and maintain it.

[Nard]

Unfortunately there isn't much do be done about this. The server has the best connectivity to Europe that the internet can provide.. the rest is just physics.

That is just false. I have far better pings with other servers in US or in Brasil. I had longer lags on patinum too. Frost (I too) already showed that lags have not an unique cause.

[AnonDuck]

Nope, this is quite true.

Let's use some traceroutes from various IP backbone providers to show it. I will be measuring the latency from California to Paris by checking the route to free.fr, a well connected mobile provider.

Let's trace from hurricane electric. They have a decent-ish national and international backbone.


As you can see, from the *backbone* in Los Angeles, to the *backbone* in Paris, it's around 160ms. This is not including latencies introduced by congested consumer internet providers.

Let's do another: Sprint/Verio

160ms

Let's try with Tiscali:

160ms

And finally from the server itself (Thanks Frost)
rtt min/avg/max/mdev = 162.379/163.488/165.092/0.950 ms

Ok. So it's pretty apparent the network latencies from the TMW server to Europe are about as optimal as they can get. The difference in latency from the server to France is in line with measurements directly from the backbone.

Now add the latency introduced by the game server software (around 20-40ms-ish, we're trying to get this lower) , the latency introduced by TCP and perhaps some packet loss from congested/cheap WiFi or a bad home internet provider... 200ms sounds quite reasonable.

On the same subject.. I find that many of my personal lag issues are caused by bad WiFi. If you have a weak signal or lots of neighbors with WiFi you should try connecting directly with an ethernet cable. WiFi *will* drop a packet now and then and when it does your computer and the server have to notice the packet has gone missing and retransmit it. This can double/triple your lag for a few seconds when it happens.

[Nard]

It already has been shown by Frost himself that network was not the only cause of lags. If the networklatency was the lag it would affect all events the same way (in average): a systematic delay. This is not the case. Also the players were affected by lags on Platinum regardless of their location.

Even if I experienced (on test server in california, I reported it already) hat a 200ms delay could affect the play in limit cases (Illia sisters) it is not the only lag cause. Thus your affirmation is false. There may be something to do about it.

edit:

Code: Select all

13. pzn-b3-link.telia.net                                0.2% 10732   52.9 424.3  42.5 39975 495.6
14. pzn-b2-link.telia.net                                0.2% 10732   44.0  42.6  41.9  79.1   1.3
15. inea-ic-150741-pzn-b2.c.telia.net                    0.3% 10732   44.0  47.7  42.8 39887 385.1
16. kaskada-c3-jar-k3m5.cr.inotel.pl                    64.1% 10732   45.7  44.6  43.6  66.1   1.0

This shows almost 40s network lags on two nodes. std deviation is also a better indicator of network stability than average delay.

[AnonDuck]

*rolls eyes*

As I stated above(twice), causes of lag in the game-server are slowly being traced and eliminated. If you would like to help by taking a look at the code and run it through gprof to find the rough spots and improve them, feel free.

[Nard]

Thats exactly what I do. I also suggested different ways to compile. Unfortunately I am far better in Fortran and even Pascal than in c or even c++. And I am a simple mechanical engineer, not a computer science specialist. too

[AnonDuck]

Still, more eyes are better. Please let us know if you find anything

[Nard]

Still, more eyes are better. Please let us know if you find anything

Thank you for asking me. Other contributors will be happy to know that I'll begin now to report issues when I find some.

[Cassy]

I already asked in the IRC but got an error message. Sorry for disappearing after asking.

I got really heavy lag today. F10 told me I have a ping between ~280 - 1'200 ms.
I only have a ping that high on TMW, nowhere else.
But on the other hand no one except me had those problems, not even others from Germany.
I just don't understand how this is possible?

[o11c]

This usually means you have a bad ISP, or are on WIFI.

When the server was in Europe, you could afford a couple of retransmissions before it got bad ...

(I haven't actually checked packet loss on the server though ...)

We do have a few retransmission optimizations queued up ...