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What happens when you make a move in lichess.org?

davidreis.me

101–110 of 162 posts

Re: What happens when you make a move in lichess.org?

#101
post #60

Earlier quoted context omitted.

> it feels like the SERVER is tracking the time TBH this is what I expected for all online chess. How else to reconcile the two players' differing clocks and also prevent client-side cheating?

I guess my naive frustration comes from crazy fps games tracking things so precisely and yet somehow Chess.com can’t handle a turn based game?! Honestly. I do recognize that fps games utilize predictive algorithms and planning to estimate future player positions but still, turn based networking with 100ms accuracy should be a solved problem

Yeah honestly I agree like it would be nice if they switched to WebRTC or UDP.

Re: What happens when you make a move in lichess.org?

#102

I wish the article explained how it dealt with message loss from the at-most-once redis pub/sub channel

I have no idea, but the in-house pub/sub tech at a previous job used [PGM][1] together with some hand-written brokers and a client library. The overall delivery guarantee is at-most-once, but in over ten years and across tens of thousands of machines in multiple datacenters, they never saw a single dropped message. Not sure how they measured that, but I was told the measurements were accurate.

Well, except for that one major outage where everything shit the bed due to some misconfiguration of IP multicast in the datacenters, or so I was told.

So, maybe if your mission isn't life critical, you can just wrongfully assume exactly-once delivery.

[1]: https://en.wikipedia.org/wiki/Pragmatic_General_Multicast

Re: What happens when you make a move in lichess.org?

#103

Earlier quoted context omitted.

Because I don't use microservices, I don't need 10,000 requests a second to play a video file.

I think the point was 10,000 files on 10,000 different hosts, per second.

Well, if they’re only watching one second of video that’s easy. The files could be super small too.

Okay, I can’t keep this up. I was parodying the position not being serious.

Re: What happens when you make a move in lichess.org?

#104
post #72
post #37

So essentially lichess chose StackOverflow approach - (rather) beefy servers, instead of "treating them like a cattle". Interesting that they accumulate and periodically store game state. Unfortunately it is not very clear, where they store ongoing game state - in redis or on server itself. Also cost breakdown doesn't have server for redis, only for DB. BTW, their github has better architectural picture, than overly…

I remember Meta having a few outages of their own. And outlook as well. So I'm not sure what to think now. But sure, on paper FAANG is redundant and hence better.

In my experience, issues scale exponentially with scale. So handling 10x the traffic might mean 100x the potentially issues. Redundancy helps with that so when something inevitably fails, the architecture is able to automatically recover and the end user doesn't see any degradation. So what works for lichess wouldn't work for Meta.

Re: What happens when you make a move in lichess.org?

#105

I wish this discussed the timing arbitration of each move. Based on the packet information (if that is correct & complete) then the timing is done entirely on the clients. However, they show the time in seconds which can't be right so I am curious how accurate this packet schema is (or if those are float values). Regardless, one thing I find maddening about chess.com is the time architecture of the game. I haven't se…

Chess.com software might be the worst public facing software ever assembled. During their most popular weekly tournament (by the number of spectators) called Titled Tuesday where significant % of the world elite regularly competes they send links on a public chat to a 3rd site every 4 rounds. The reason is that there is a few minutes break and they failed implementing a clock on their side so they need 3rd party service for that.

This is one of the many, many things but imo it's the most telling. They can't even add a clock counting down the 6 minutes to their web client.

Re: What happens when you make a move in lichess.org?

#106
post #56

Earlier quoted context omitted.

I'm surprised to see anyone bring him up here!

You're surprised that Kramnik is mentioned when the discussion topic is related to chess? I don't understand why. He's well-known in chess (and in chess memeland).

Kramnik is a former world champion who has taken a torch to his own reputation by accusing tons of people of cheating without evidence. He’s been banned as a regular columnist on chess.com after using his column as a platform to attack people. He has next to no credibility on any chess issues these days.

Re: What happens when you make a move in lichess.org?

#107
post #73

Earlier quoted context omitted.

I'm pretty sure freechess.org did.

How is it being done client side?

Freechess shipped a binary called “timeseal” that did the calculations for you and encrypted the communications. It was not foolproof—-not by a long shot, but it also didn’t completely suck.

You can read about what became timeseal here. https://eprint.iacr.org/2004/203.pdf

Re: What happens when you make a move in lichess.org?

#108
post #37

So essentially lichess chose StackOverflow approach - (rather) beefy servers, instead of "treating them like a cattle". Interesting that they accumulate and periodically store game state. Unfortunately it is not very clear, where they store ongoing game state - in redis or on server itself. Also cost breakdown doesn't have server for redis, only for DB. BTW, their github has better architectural picture, than overly…

The downtime here is mostly OVH's fault. They're not known for fast support on hardware failures, that's why they're cheap. If they had this architecture on AWS EC2 and could just spin up a new AMI, then they'd only have a few minutes downtime, and the same simple architecture.

Re: What happens when you make a move in lichess.org?

#109
post #44

nit: fen only encodes board state, not game state Edit: also includes move count but not repetition.

How is the game state not just the board state? Move history doesn’t matter in chess (FEN encodes the 50 move rule)

Unfortunately move history does matter

Re: What happens when you make a move in lichess.org?

#110
post #29

Earlier quoted context omitted.

If you consider this to be true, you would seem to have a rather low standard. There are many aspects in which they are not the best.

Like? Ad-free, compute intensive, non-CRUD, massively scaled, complex cheat moderation, infinite puzzles/analysis, educational (studies/tactics/openings explorer), etc. All this for free. I'm curious what's the best website in your opinion

I could elaborate, but rather, let me ask you this instead since its more relevant.

What is the point of responding with any legitimate criticism when any potentially negative sentiment however mild, upfront, expressing disagreement, gets downvoted to the point where the mechanics of the website squelches the person and silences them (by purposeful intent).

Can you ever have any legitimate intelligent conversation after a participant has been harmed and effectively silenced in this way?

When you cannot speak freely, there can be no intelligent communications raising the bar objectively. The opposite occurs, and anything provided, even seemingly rational conversation falls after such a threat or action of violence, all conversation then falls into the gutter as a result of the added coercive cost imposed. You may contend that its not violence, but it meets the WHO definition for such which properly accounts for psychological torture and coercion (of which this is a common form).

It should go without saying, but you cannot have any intelligent conversation when those who embrace totalitarian methods prevent you from speaking (and yes these meet the criteria).

At the point this happens, regardless of valid criticism, or pointing out errors in methodology, it all dies on the vine, the communication is clear; you will be punished for disagreeing. That destructive behavior inevitably leads to ruin.

This is fairly basic stuff, in order to think and be intelligent, one must be able to risk being offensive. In order to learn something new, one must risk being offended.

When neither are possible because you or someone else muzzles any conversation expressing disagreement or corrosively add cost, even under such modest terms as here, the fallout is silent, yet devastating.

It might not seem like much, but the light goes out of the world as those with intelligence withdraw their support, and the natural consequences which were held at bay by these people, albeit slow moving, become inevitable.

Best of luck to you. There is only the possibility of harm by continuing any discussion under these circumstances.

I'd suggest remembering this when you start wondering, "where have all the intelligent and competent people gone?".

Silence doesn't indicate agreement. It is indicative of the best and brightest no longer contributing to the same systems that seek to destroy or enslave them.

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