Death by Buggy Block-Lag - "Caught Walking In Walls"

[CuriousNoob]

Hi again

Just to report/enquire/complain about a frequent problem which can make an online game totally unplayable...

It's an issue of buggy environment-catchup when digging or placing blocks.

Unpredictable updating of changed-blocks has killed my player more than once. Dead! :(

The phenomenon is this :

After digging/placing blocks, during the next several seconds, dug-blocks can suddenly reappear and placed-blocks can suddenly disappear. They usually revert in a moment or two, returning as intended, although not always completely.

It also happens in a seemingly random haphazard fashion, definitely not in the exact sequence you'd just dug or placed them.

As they revert, it's a bit like watching a sketchy stuttering out-of-order phantom replay of what you've just done.

It's inconvenient and wastes time, but remains benign while standing static in one place (as, for example, when briefly chasing an ore-seam off to one side of your tunnel and then back-filling with cobble).

Sadly, it's the dynamic situations cause the real problem.

1 ) - Digging - Walking across a space you've just cleared, or shortening the sand-scaffold-tower you're standing on, only to find a few seconds later that you're whacked with red-screen pain-flashes or worse, suddenly confusingly plunged into blackness, apparently entombed INSIDE the reappeared blocks!

The in-game consequences range from a fleeting ouch to massive health-point/armour damage to full-on death and, in one case, loss of all my inventory tools/items too. In that instance no bones appeared where I'd died, in fact, nowhere at all, despite returning and digging far and wide in the area which had suddenly entombed me -- it was all solid blocks, no bones on the above-ground surface either! (For the record, that was in Maikerumine's generally busy Extreme Survival Minetest City.)

2 ) - Placing - When at height, using the [Shift] sneak-over-the-edge function, to build a bridge over an abyss, only to find, moments later, without warning, the blocks briefly vanish beneath your feet, long enough to send you hurtling downward.

Unlike Wile E. Coyote, you don't get time to blink in bewilderment before falling, nor walk away from the puff of dust at the bottom. ;)

At least lag is obvious when you go to use Crafting-Grids and Guides and Bags and Chests and find them taking take tens-of-seconds or minutes (sic!) to respond.

But during routine digging and placing there's no obvious warning of lag until it's too late.

Questions :

Am I right to think the problem centres on ''server lag''...?

Is database-thrashing on the servers the main culprit...?

Can any client-side config improve it...?

(Worth repeating, as per previous posts, I'm using the latest ubuntu ppa versions from the devs themselves, updated pretty-much daily.)

Are there any server-side methods Admins could use to prevent it...?

Does it all ultimately come down to hardware and OS...?

Or is there anything the Developers could do differently in the core programme-design...?

Minetest is my very-first experience with block-world games (and pretty-much computer-gaming as a whole). As such, I personally have no relevant frame of reference for comparison.

Do other similar networked games (non-FOSS block-worlds or shoot-em-ups) suffer these same sort of issues with lag and out-of-sync bugginess, and if not, what is it they're doing differently...?

How do the bigger, busier, databases in big busy organisations---state, academia, commerce, whatever---actually cope in real-time, and what is it they're doing differently...?

Server-inflicted death and loss really doesn't help gameplay, nor credibility.

Then unfair server-chat messages about being ''caught walking inside walls'' merely add insult to injury.

Anyway, still curious, still mostly enjoying auditioning this game.

So I'll be interested to hear any positive replies.

Cheers :)

.

[ABJ]

I'm on windows. I don't believe this would be an OS/hardware bug. LAG!!! I've built many a wall only for it to suddenly deconstruct - or walked straight into the enemy base while THEIR wall deconstructed.

[Byakuren]

1. The issues with digging/building can either be caused by server lag or network lag, but is more likely to be network lag. The reversals in digs/builds comes when the client receives a block update from the server that was sent before the server processed the action.

2. I don't think so, the placing and building of nodes at the rate a player can do shouldn't cause it.

3. I don't think so, though you could modify your client to do it, potentially.

4. There are settings that could help both with server lag and network lag. For example server lag could be reduced by reducing the active block and entities range, and also by removing mods that are expensive to run. Network lag could be reduced, if the server has the bandwidth, by increasing the values of max_simultaneous_block_sends_* options.

5. No, though maybe hardware and OS of the server if it is too weak to run the server without too much lag.

6. Maybe could somehow ignore block updates that came after building but before it was acknowledged? I am guessing this is already done for block updates received too soon after building.

7. Minecraft had similar issues with inventory and dig/build lag when I played it. Also the server had to confirm what was in your cursor, so there could be annoyances where what's in your cursor changed unexpectedly.

8. See above. Also I don't think shmups are usually networked. Probably shmups would use client-server with small input delay and no prediction, since the exact positions of bullets on the screen matter. So you wouldn't see issues like this, but it would be more sensitive speed-wise to lag (slower game). The only networked shmup I have played is Touhou 9.

9. It's most likely network lag or server lag caused by computations rather than database lag (see 2)

10. Server-inflicted damage is necessary for any kind of damage that doesn't come from the environment (nodes). If you want to play without damage you can turn damage off and play on servers with no damage.

11. I think "caught inside walls" messages and punishments come from mods, not the base server. You may want to complain to the server owner for installing those mods while having lag, unless the lag is due to your own bad connection.