Mob Spawn Rates on P/Rev14

[WyndySascha]

tl;dr Bad spawn rates in darkroom spawner, don't think it's simply a matter of player numbers

 

I hope this is right place to post this - I didn't want to harass any one person! - and please bear with me if I get my terms wrong, I'm not particularly technically-minded myself.

 

For clarity, I'm interested in the technical, server possible explanations of what might be wrong: I'm not asking people to solve my build design problems for me, that wouldn't be a fair thing to expect and I'm practically positive it's not a design issue; I also don't want to give any impression that I want a server technical policy changed (those discussions are for other places, I think).  I simply want to know if there's a known reason for the problem, so I don't spend any more time fiddling with a design already at the stage it should be at!

 

I've built (the relevant parts of) a darkroom spawner system on P; for the interested, its co-ords are x2540 y220 z-2390 (Ambrosia, NE Portal).  The spawn rates are terrible.  Ordinarily I'd blame myself for crappy design.  However, I've built this setup before on servers and in single player worlds and the spawn rates are much, much higher.  Quick design description:

• 9 darkrooms
• all build high-up enough so they're the only places where something can spawn
• each darkroom containing 4 spawning pads
• each pad measuring 3x3, with a slab in the centre to limit spawns to 2x1 mobs
• ... for a total of 288 spawning surfaces, each of whose light levels are <8
• player spot is 24-32 blocks away from each surface

So, all pretty straightforward.

 

However, as I say, the rates are terrible.  I suspect I'm falling foul of one or all of several things:

• An overall, server-wide mob cap beyond the ordinary that I'm unaware of and doesn't seem to be documented under /moblimiter (although the latter applies to chunk unload despawning, so it probably wouldn't be)
• what's outlined in this subreddit post (although I feel I've played on servers with more people than right now at a short while into P/Rev14 and not had rates these bad) [EDIT - players were kicked from P today, on re-logon there were only twelve of us, did a test - rates were still just as bad]
• This bug, which I've reproduced in a local Creative world:
  • [1.7.10 local Creative] render distance <10, spawn rates tank with the above design
  • [1.7.10 local Creative] render distance >=10, spawns are what you'd expect with the above design

(... I'm fairly sure the chunk render distance on P is currently set to 5)

 

Can someone please shed some light?

 

Thanks in advance, and to anyone whose ear I've already bent over this! :D

Edited September 6, 2014 by WyndySascha

[jllmprrt]

It actually has a lot to do with player numbers. Since the mob cap is shared, it's difficult to get mobs to spawn in one place. Sorry about this; nothing wrong in your design of the farm.

[sansapants]

From purely anectdotal experience, darkroom spawners haven't worked well since Rev 9. That rev, WaterSlide built one in Brom that worked quite well.

 

A similar one built in Rev 10 performed poorly, or at least not nearly as good as the one from Rev 9. I don't recall hearing about others building successful darkroom spawners in revs 11, 12, or 13. Human nature being what it is, hopefully my statement will cause others who have evidence to the contrary to quickly prove me wrong.

 

*Why* darkroom spawners don't work is a mystery to me: I simply know that they're generally an exercise in futility on this server.

[Denevien]

From purely anectdotal experience, darkroom spawners haven't worked well since Rev 9. That rev, WaterSlide built one in Brom that worked quite well.

 

A similar one built in Rev 10 performed poorly, or at least not nearly as good as the one from Rev 9. I don't recall hearing about others building successful darkroom spawners in revs 11, 12, or 13. Human nature being what it is, hopefully my statement will cause others who have evidence to the contrary to quickly prove me wrong.

 

*Why* darkroom spawners don't work is a mystery to me: I simply know that they're generally an exercise in futility on this server.

I'm going to go out on a limb and say this is partially my fault. It was around this time that I became a PAdmin, and we were looking at options to help with the terrible lag. I do believe this is due to the moblimiter stuff. After a certain number of mobs in a chunk, no more will naturally spawn (this goes for anything). Thinks like cows/chickens/pigs can be bred past that limit, but will be culled on chunk unload. Since there is no way to "breed" zombies/skeletons/creepers, they are limited to the chunk limit. The problem I see in this is that many of the darkroom designs I've seen has dark spots with water to push them when they step of the spawn pad. This is a very slow way of getting them to the player, thus you hit the cap before many get built up. The best way to maximize a darkroom grinder would be to prevent any mobs from being in the chunk (including underground). I don't really think there is a way to revive dark room grinders to their previous glory without bringing back the game crippling lag of the old days.

[WyndySascha]

I'm going to go out on a limb and say this is partially my fault.

BLAME!! WE HAVE BLAME!! KEEEL HEEM!! XD

But Seriously, Denevien, and jll and sansa: thanks for your answers: they cover two of the three things I thought might be to blame. I'm still not sure about the role of sheer numbers, but it seems plausible - I suppose that, as the Rev progresses and opportunities arise to run the grinder with very few players on, it'll be something that's test-able.

Does anyone have any thoughts on the bug I mentioned? Is it observable on P?

[totemo]

Former tech admin and long term dark-room grinder enthusiast here.  A few points:

 

• It doesn't matter how well your design performs on C or in single player.  The conditions are completely different on P and more adverse to dark-room use.
• The per-chunk spawn rates may be tuned well down on P to mitigate lag, in the Spigot (server) configuration.
• MobLimiter may also have per-chunk culling of hostile mobs in its configuration. Thought the plugin was originally conceived as a way to reduce passive mob numbers, it has been adapted to control hostiles in the last year.
• The entire world-wide mob cap (number of loaded chunks times chunk limit) is spread evenly among all online players.  No darkroom will perform well with 120 players online.  Wait until there are only 12 players, later in the rev.
• Your dark room is too small.  You need something at least as big as this: http://imgur.com/a/vQjbC#47 . That's 18 floors per tower, with each floor wired to release water behind pistons into the four corners of the room.  Except you need to go ahead and wire up all four towers.  Or for a more efficient design with parallel-flowing water, hunt down WaterSlide and ask him about some of his Brom dark-room grinders.
• You need to build your darkroom in the middle of an ocean, so that surface-spawning of mobs is impossible.  You also need to light up at least 99% of all cave space everywhere where chunks are loaded, starting with a 15x15 chunk square around your grinder and then moving on to the same area around every online player.  Then get everybody to stand perfectly still so that you don't need to light up more chunks.  Alternatively, if you can persuade everybody else to log out, you will get the full mob cap in the vicinity of your grinder.  Mobs in the grinder are killed quickly, whereas mobs in unlit caves tend to hang around a long time, so dark space in caves counts proportionately higher than dark-room space when it comes to spawning.

Edited September 7, 2014 by totemo

[WyndySascha]

Thanks for your reply totemo! ^{totemo sees all}

 

I'm afraid I'm just not able to make the sort of time commitment to Minecraft and P that would let me build all the Big Wonderful Things, which obviously makes me sad. :(  I was never looking for spectacular rates, just not as bad as what I've got, so I might concede defeat for the time being.  That having been said, the info that's been shared has made a few different ideas swirl around in my head so I might revisit things later in the Rev.

 

Thanks for everyone's help and advice, especially as it relates to P-specifics! :D

Edited September 9, 2014 by WyndySascha