What is Desync? (A thorough explanation)

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ScrotieMcB wrote:

Some questions:
* how much information is sent when the game state changes? Are multiple empty/unchanged fields communicated in addition to the changed fields? How much space do headers/footers/labels occupy?
* what kind of compression, if any, is used on client/server communication? Would it make a significant difference?
* what kind of encryption is used on client/server communication? Could a different encryption method be more compact without exposing significant additional vulnerabilities? How often are keys changed, and if often what percentage of bandwidth does it use?

I'm sure these questions, and more, are being discussed by the coders responsible for fixing the issue. The primary issue is resources and time. GGG is a 20 person studio, not all of those 20 people are coders working on desync.

As they make positive adjustments and more people tell their friends about PoE, the more server load increases and what was an acceptable amount of server load with the old playerbase size is no longer acceptable and they have to adjust again.

A moving target is a hard one to hit. :/

I bolded the sentence in the OP. I might do more at some point. Think of it like my friendly gesture to the twitter generation. I promise not to highlight more than 140 characters at a time.

I don't believe this thread was ever about finding solutions (although I do appreciate your go-get-'em attitude, Scrotie). It's just information. Explanation.

The stuff about Diablo 3 not having a 'to hit/miss' function is particularly salient.

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Charan wrote:

The stuff about Diablo 3 not having a 'to hit/miss' function is particularly salient.

Sssshhhh, the monkeys with sticks will freak out at not knowing what 'salient' means and they they might remove the sticks and start with the poo flinging and the screeching!

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CrystalisQualinthi wrote:

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Charan wrote:

The stuff about Diablo 3 not having a 'to hit/miss' function is particularly salient.

Sssshhhh, the monkeys with sticks will freak out at not knowing what 'salient' means and they they might remove the sticks and start with the poo flinging and the screeching!

It wasn't salient. I read it out loud.

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Jim_Fear wrote:

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CrystalisQualinthi wrote:

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Charan wrote:

The stuff about Diablo 3 not having a 'to hit/miss' function is particularly salient.

Sssshhhh, the monkeys with sticks will freak out at not knowing what 'salient' means and they they might remove the sticks and start with the poo flinging and the screeching!

It wasn't salient. I read it out loud.

wait...what?

A good effort, but I'm pretty sure most of the people that would need to read this don't give a shit and are probably going to continue blaming all of their problems on the omnipresent desync.

"I put a passive point into the wrong node omfg desync! GGG give me full respec!"

Salient Green is People!

...don't mind me.

There, highlighted tpapp's work for the 'speed readers' out there. You know who you are.

While long and amusing, there are a huge number of incorrect assumptions and inaccuracies in that post. Client synchronization is not some huge "all or nothing" proposition, where it's either nothing gets updated and we just assume it's all in sync or we force the whole game state update to occur. The desyncs this game experiences also have little to do with the "client predictive" local movement system, which is used in almost all FPS games as well as some MMOs such as Guild Wars 2 with little or none of the artifacts present in this game.

In reality, aside from the game appearing to have little or no system for update prioritization and either no system for sending only a unit's location or it just isn't working, most of the desyncs are caused by collision and tick non-determinism combined with their decision to consider dynamic objects as pathfinding blockers (which is questionable for gameplay reasons in addition to the networking effects - ever see a single skeleton entering a doorway cause all the other enemies to suddenly decide to run around the level to avoid the same doorway?)

While it's true networking is never going to be perfect, particularly for poor souls stuck with 200+ ping because there's no local server or their ISP sucks, there's really no good reason why low ping, no loss connections shouldn't be in sync or very close to it 99% of the time.

However, in fairness to them, re-architecting poor networking decisions after the fact is generally really hard. Networking isn't something that you can just "bolt-on" to an existing game and it magically works; a fair amount of game logic has to be based around the networking scheme. Doesn't excuse the amount of time I hear this issue has been around, though.

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Mysterial wrote:

However, in fairness to them, re-architecting poor networking decisions after the fact is generally really hard. Networking isn't something that you can just "bolt-on" to an existing game and it magically works; a fair amount of game logic has to be based around the networking scheme. Doesn't excuse the amount of time I hear this issue has been around, though.

This part interests me. So, when building the game, why would GGG (or any company for that matter) make poor decisions in the networking department when their entire game rests on that very foundation?

I can't imagine they did it on purpose knowing something like this is hard to fix later on. In your opinion, what would be the reasons for doing this?

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Jim_Fear wrote:

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Mysterial wrote:

However, in fairness to them, re-architecting poor networking decisions after the fact is generally really hard. Networking isn't something that you can just "bolt-on" to an existing game and it magically works; a fair amount of game logic has to be based around the networking scheme. Doesn't excuse the amount of time I hear this issue has been around, though.

This part interests me. So, when building the game, why would GGG (or any company for that matter) make poor decisions in the networking department when their entire game rests on that very foundation?

I can't imagine they did it on purpose knowing something like this is hard to fix later on. In your opinion, what would be the reasons for doing this?

I know!!! I know!!!! Pick me!!! Pick me!!!!