Turn rollback ramifications

sansanjuan · #1 January 24th, 2011, 07:09 PM

We are considering rolling back a turn on llamaserver. I've been through a rollback on another game with no ill effects but thought I'd ask if anyone has a feel for issue likelihood and seriousness. I understand (maybe incorrectly) that unit ids can sometimes get messed up with troubling consequences. Anyone know if this happens to occur once in a blue moon or much more often? If it is potential big trouble we can perhaps comp the affected player in another way.
-ssj

PriestyMan · #2 January 24th, 2011, 07:25 PM

Basically, anyone who has been through more than a couple rollbacks understands the #1 rule about rollbacks- never, ever, under any cercumstances do them unless the game is literally at stake. there is a million things that can go wrong, items dissaperaing, units dessapearing, commanders becoming units, units commanders, orders not followed, gold/gems vanishing. I have personally, and many other vets as well, have seen games entirely ruined by rollbacks.

Now to be fair, every once in a while rollbacks go without a hitch, but generally people agree that its not worth the risk of ruining the game.

Executor · #3 January 24th, 2011, 07:58 PM

No rollbacks! Don't consider it! Don't even think it! Rollbacks are the work of the devil, and whoever suggests them for whatever reason is a Dominions terrorist and should be banned from the game!

Seriously tho, couldn't agree more with Priesty. It's only to be used in the most dire of dire situations and never, I repeat *never* just to accommodate someone which is usually why people use them...

thejeff · #4 January 24th, 2011, 08:11 PM

Thirded. Don't do it.

If you really must, a couple of suggestions:
The llamaserver still has your old turns. Anyone who hasn't submitted a new turn since the problem one does not have to send one in, and probably shouldn't.

More importantly, if you do rollback, before you get the new .trn file, delete the existing .trn and .2h files in your savedgames directory. This stops at least some of the problems.

Gandalf Parker · #5 January 24th, 2011, 09:17 PM

I know you said LLamaServer but let me chime in a vote also.

On my server (Dom3Minions.com) rolling back the games is very simple. The script that runs each game includes a backup which zips up all the files just before each hosting. So every file is saved just as it was before the turn rolled. All I have to do is stop the game, unzip the file, and restart the game. And I store the last 3 turns. (more if the person running he game has requested that they be emailed to them each turn)

On the SERVER end its very simple. BUT I still highly recommend that it NOT happen. Its not the server that messes it up. Its the players. Unless they completely delete their game files their is a chance of messing up the rollback. Things can get so tangled that it can kill the game.

So as others have said, dont do it unless its a game killer. If the game can continue, then just continue. If its because someone missed their turn, even for a good reason, dont do it. If its because someone thinks the server messed up, dont do it. Just treat it as a bad event and keep going. IF there is some kindof a vote going on then dont just consider it as "do they have a good enough reason to request it". Consider it as "do they have a good enough reason to chance trashing the whole game over it"

NTJedi · #6 January 25th, 2011, 03:24 AM

Quote:

Originally Posted by sansanjuan

We are considering rolling back a turn on llamaserver.
-ssj

Rollbacks are forbidden even for Superman:

Rollbacks how we want them to occur for Dominions_3:
http://www.youtube.com/watch?v=CCsHT...eature=related

Rollbacks for what really happens for Dominions_3:
http://www.youtube.com/watch?v=UwG5C...eature=related

Dimaz · #7 January 25th, 2011, 06:43 AM

When I was manually hosting games before llamaserver appeared, rollbacks were almost a no-issue. 1) Make sure that nobody has unfair advantage (ie not use the 2h files for first turn that were sent after players saw the outcome of battles in that turn). 2) Tell all the players to completely delete game files for that particular game. After that you just host the backup copy with old 2h's and send them as usual, nothing will be messed up.

llamabeast · #8 January 25th, 2011, 07:29 AM

At the server end, it is indeed true that rollbacks are simple. If you keep a tight leash on your players there should be no problem. However, there normally is a problem. Problems come in two kinds:

1) Players feel that it was unfair in some way. Presumably only a subset of players get to retake the turn, and those players now have knowledge of the future. Anything skillful that they do in that turn is tainted by the thought that even the most honest of players can't help the subconscious effects of knowing stuff they shouldn't.

2) Players accidentally send in 2hs from the wrong version of reality. Consider the situation:

- Turn 24 is processed
- All players get turn 25. Some start working on their turns.
- The game is rolled back to turn 24, then hosted again to get to an ALTERNATE REALITY version of turn 25.
- Some players send in 2h files based on the first version of turn 25. Or even, they use the 2h they had started work on as a starting point when working on the new turn 25. This will cause CRAZY THINGS to happen. Dominions will not reject 2h files based on the alternate reality (correct game, correct turn number, all checks passed), but it will go a bit mad.

--

Here is the safest way to do a rollback. We'll carry on with the above example, where we're on turn 25 and roll back to turn 24.

- Contact the player who needs to redo his turn. Get him to send his 2h file for turn 24 to you (the admin).
- Rollback the server.
- Immediately send in the 2h file for the player who needed the rollback.
- Immediately force hosting. This is cunning because it avoids the server being in the rolled back state for any length of time, and eliminates any suggestion that any of the players who were not meant to resubmit their turns may have done so.
- Send a message to all players (via the llamaserver system so they get an e-mail and don't have to check the forum) telling them to DEFINITELY DELETE ALL 2h FILES. This is very important.
- The game can now continue as normal.

Hope that helps!

(And sorry I didn't reply to your PM ssj.)

WraithLord · #9 January 25th, 2011, 10:07 AM

I suggest to never do rollbacks with the exception of the following three reasons:
A- llamaserver dom crashes when hosting the turn thus everyone stale or some such (make sure to report to llamabeast)
B- See A.
C- Same as A.

llamabeast · #10 January 25th, 2011, 11:03 AM

Heh, well a rollback is worth trying in that situation, but I would expect the same thing to happen again! In fact it would be somewhat mysterious if it didn't.

Anyway if you did want to rollback in that situation it would at least be very easy to try, since the admin could rollback and then force hosting without any players getting involved. On the downside, whenever dominions crashes on llamaserver, what is generally actually happening is that hosting takes infinite time rather than crashing outright. I then have to go and kill the process, and in the meantime everyone wonders why the llamaserver has stopped working (it's not allowed to host more than one game at once, so all other games will get stuck waiting for that game to host; also the "Last updated" time will stop updating which is really just an indication that it is unhappy).