minecraft-java-edition
In my server.properties, I have game mode set to 0 (survival), spawn rates set to defaults (1 tick for mobs, 400 ticks for animals) difficulty set to normal and we are harldy seeing any mobs or friendlies.
We even have a mob-grinder which is failing to spawn more than 1 mob per-day.
This is running on craft-bukkit 1.2.5
Our host seems to think that others have reported the same sort of issue. Does anyone have any ideas what the underlying issue may be?
There are two points to remember that may seem contradictory: first, like Nicholas pointed out, you need to makes sure that your mobspawner is the only nonlit space in a pretty big area around you (I think the area's actually about 150x150 blocks), but second, you need a lot of empty space around. In other words, minecraft will choose places that have a lot of surface area (not volume) to spawn mobs in, so if you were to have a lot of open caves beneath your mobspawner, the game will flag that area as more likely to spawn mobs in. You just also have to make sure that it's all well-lit, then you've effectively tricked the game into flagging that area to spawn mobs in, but then conveniently your mobspawner is the only dark area where it can do so.
I would recommend you take a look at this tutorial. You may not want that particular style of mobspawner, but it goes over the prerequisites of any good mobspawner quite nicely.
There are a couple of problems you could be having. As has been stated in comments above, very likely many of the mobs are spawning in other areas. Also, if you have moved up 13 levels you have greatly increased the places where mobs can spawn. If you're on bedrock, the area on the surface (assuming you're under land, and not water) is considerably smaller where mobs can spawn, than if you're up 13-20 more meters.
The second issue, is that mob caps are computed globally on a multiplayer server, so if someone pops up on the server, and starts up a mob grinder, basically all the mobs can be spawning in their areas, and not in yours. You have to out compete them on spawning space. 50x50 may not be very large for a well established server.
Finally, keep in mind that most mobs only move if they are with 32 meters of the player. So, water pads like you have are of limited utility if you are far away:
Best Answer
I'm not sure what the answer would be but this problem has been resolved. It could well be some problem with our host as they reported other users with the same problem. The rendered entity count never went over 3 in any direction. Tonight though, we are seeing plentiful supplies of mobs and animals from surrounding areas. We've not really explored that much so we're definitely putting it down to a glitch of some sort.