On-line engine blitz tourney February

[Joost Buijs]

The monthly on-line engine blitz tournament for February will take place on:

Saturday, February 14, 2:00 PM EST (Boston time) 20:00 CET (Amsterdam time)

To connect, use the following command:

winboard -zp -ics -icshost nightmare-chess.nl -icshelper timeseal -fcp ENGINE.exe -fd ENGINEFOLDER -autoKibitz -keepAlive 30
(For UCI engines, add -fUCI)

If you don’t have an account, please submit a request to admin@nightmare-chess.nl.

Our tournament manager will be Eendje (Lisebeth @ ICC).

The format will be 9 rounds, Swiss system, 5/1 time control.

Lisebeth prefers to start the tournament on the hour, so please log in 15 minutes early. Late entries are not supported.

PS.

It appears that last month’s server crash was caused by the timeseal decoder, which also brought down the chess daemon and mamer.

Since I don’t have the source code for the timeseal decoder, it’s impossible to determine exactly what went wrong.

The annoying part is that mamer does not save intermediate results, so after a crash the tournament has to be considered lost.

As a precaution, I have replaced the server hardware and reinstalled Linux from scratch.

This was only the second crash in seven years, so the chance of it happening again is small — let’s hope for the best.

[Joost Buijs]

Hi All,

Unfortunately the server crashed again, this time already in the first round.
The strange thing is that it worked seven years long without problem, and now it suddenly seems to be unstable.
The software didn't change at all, only Linux Mint was upgraded from 21.1 to 22.3.
After last months crash I even changed the hardware and reinstalled everything from scratch.
The 'Lasker' chess server software is very poorly written, uninitialized varables and dangling pointers everywhere, since I don't want to spend a lot of time to find out what the culprit is, it's probably wise to quit with this tradition completely.
It was fun for as long as it lasted.

Joost

[Maarten Claessens]

What about installing Linux Mint 21.1 in a Virtual Machine (VirtualBox) and running the chess-server from there?

[hgm]

This is why I am still running Ubuntu 10.04. Never upgrade something that works...

BTW, I think when I still was running these tourneys from my home I did replace the timeseal decoder at some point. Or was it just the communication with it?

Anyway, the protocol is known, as we have the source code of an openseal decoder. And it is quite trivial. The decoder is probably just a 20-line program.

[Joost Buijs]

What about installing Linux Mint 21.1 in a Virtual Machine (VirtualBox) and running the chess-server from there?

Of course it's possible to switch back to Linux Mint 21.1 or to run 21.1 in a VM in the hope that it solves the problem, but it could be something totally different.

I remember HGM having the same problem with this software, it was stable for years, and suddenly it started crashing without any reason. Maybe the database is getting to large, or maybe the database gets corrupted. Last time the time-seal decoder crashed, from which I don't have the source, it could be crashing if somebody sends garbage to it, I really don't know.

I will save the user database, maybe somebody else would like to try to get it running, but I don't feel like spending time on it anymore.

[hgm]

I once had to fix a bug where the ICS crashed on receiving too long lines from the decoder. This also appeared suddenly after years of problem-free running. Because engines started to send ever longer PVs.

So apart from Linux upgrade it could be due to a buffer overrun in the decoder.

[Modern Times]

Sorry to hear about this Joost. Many thanks for all the effort you've put into this over the years (and HGM previously as well).

[Joost Buijs]

I once had to fix a bug where the ICS crashed on receiving too long lines from the decoder. This also appeared suddenly after years of problem-free running. Because engines started to send ever longer PVs.

So apart from Linux upgrade it could be due to a buffer overrun in the decoder.

That fix is still in place, you restricted the line length to 1000 chars. I also noticed when I throw a lot of garbage at the server that it still crashes, of course this should not happen.

Recompiling it with current compilers is also a 'no go', it compiles but both the executables chessd and mamer are clearly broken after this.

Of course everything can be fixed, but this will probably take several days, and the problem is that I have to setup and run test tournaments to check whether everything is stable or not.

[mar]

The 'Lasker' chess server software is very poorly written, uninitialized varables and dangling pointers everywhere, since I don't want to spend a lot of time to find out what the culprit is, it's probably wise to quit with this tradition completely.
It was fun for as long as it lasted.

Joost

please don't quit Joost, I think this tradition is awesome!

a chess server is only software. so I guess it can be replaced, if not, assuming
it's open source, then it can be fixed.

I guess there are no logs so it's impossible to track what exact input caused the crash?

I only found lasker chess server source on josh shriver's github, I guess that's not it? https://github.com/jshriver/lasker

[Ras]

I suggest giving the source code a check with compiler warnings cranked up, and also with CppCheck (free / open source), maybe it finds something?