First time poster, but I felt that this was a big enough issue for a lot of people and that the way I solved my particular problem might help out others in a similar situation.
I'm relatively new to the game and I am working on my first ever survival world. In the beginning, mobs seemed to spawn normally, but over time they spawned less and less. Doing a little research online, I found out that this is a typical problem and to be honest I didn't mind not having to worry about mobs while working through the night and me and my kids could build/mine in peace.
However, the issue then became that neutral mobs were no longer spawning, and then we started having lag issues. My kids playing on their tablets were then unable to do anything in my world due to lag (to the point where even opening a chest was a problem). When I started having lag issues even on my high-end laptop, I know I had to do something. Based on my research, I figured that I had to go caving under my base area, find where the mobs were hiding out, kill them, and light the place up.
The issue came to a head when my oldest son asked why I was hearing skeletons while working on my melon farm... my response was that I heard that sound all the time and I guess I just never knew that is what skeletons sounded like. He then told me that there was a ravine that we hadn't explored yet that had some skeletons at the bottom that might be the problem. He said that they called it "googlie ravine" (watching too many Stampy videos). He wasn't kidding....
The issue was that I had a skeleton spawner in a dungeon about 7 blocks right below my farms. The dungeon was linked to a cave that opened out into a fully underground ravine, so that skeletons wouldn't stay around the spawner for too long. To make matters worse, the bottom of the ravine had an area where water was flowing in a such a way that skeletons were getting caught in the stream and forced into a pair of blocks. I dug down parallel to the ravine, created a little kill chamber (literally a spot at floor level 1/2 block high where I could hit their feet and they had trouble shooting me), and cleared out about 50 skeletons to the point where I could disable the spawner. The was easy enough.
Where I almost really screwed up is when I went to try and figure out how to clear the skeletons out at the bottom of the cave where they were caught. I created another small opening to kill about another 50 skeletons not caught in the water, but then I made the mistake thinking that the coast was relatively clear. When I poked my head around a corner to see the spot where the mobs were caught, I saw that the spot was totally glitching and I moved out of the way just in time to not get hit by 50-60 arrows. I decided to block the water stream to see if I could free them... HUGE mistake. Once the water was no longer holding them, 100-125 skeletons literally exploded out from the block that they were trapped. After running for my life, I figured out how to slowly coerce them out to where I could kill them in my little kill chambers.
After all that, I was still having lag issues and I could still hear skeletons so I figured that I didn't free all of them. Sure enough, the second spot where they were stuck still had water flowing into it. Instead of turning off the water, I just broke/set blocks up so that I could get into position to shoot them with arrows without them seeing me. It took me two full stacks of arrows killing another ~110 skeletons to finally kill all the rest. So yeah, after killing almost 300-350 skeletons (including two spots that were so dense with mobs that they were glitching like crazy), mobs almost immediately began spawning correctly again and the lag issues totally went away.
Some takeaways from this:
1) Mobs from spawners will not despawn because they have "persistence". I guess this is fine for mob farm purposes, but to me this seems like it is a very probable factor in why the mob cap fills up so quickly in some cases.
2) Mobs from spawners will contribute to your mob cap preventing other natural mob spawning. The official wiki is worded awkwardly on the issue, but I've tested this out on a separate world and confirmed this.
3) Spawners will continue to spawn if you are within 16 blocks (in any direction) even if you are over the mob cap (i.e. they contribute to the mob cap, but are not affected by it). Again, this seems like this is necessary for mob farms, but this also seems crazy to me.
4) Bedrock has no "entity cramming" restrictions and I found that this was a significant source of lag. I know that this is not new information, but that fact that it can happen in an unexplored cave without me ever knowing what was going on also seems crazy to me.
Anyway, that is my story. Hopefully, this will help out anyone else who is having mob spawn and/or lag issues.
First time poster, but I felt that this was a big enough issue for a lot of people and that the way I solved my particular problem might help out others in a similar situation.
I'm relatively new to the game and I am working on my first ever survival world. In the beginning, mobs seemed to spawn normally, but over time they spawned less and less. Doing a little research online, I found out that this is a typical problem and to be honest I didn't mind not having to worry about mobs while working through the night and me and my kids could build/mine in peace.
However, the issue then became that neutral mobs were no longer spawning, and then we started having lag issues. My kids playing on their tablets were then unable to do anything in my world due to lag (to the point where even opening a chest was a problem). When I started having lag issues even on my high-end laptop, I know I had to do something. Based on my research, I figured that I had to go caving under my base area, find where the mobs were hiding out, kill them, and light the place up.
The issue came to a head when my oldest son asked why I was hearing skeletons while working on my melon farm... my response was that I heard that sound all the time and I guess I just never knew that is what skeletons sounded like. He then told me that there was a ravine that we hadn't explored yet that had some skeletons at the bottom that might be the problem. He said that they called it "googlie ravine" (watching too many Stampy videos). He wasn't kidding....
The issue was that I had a skeleton spawner in a dungeon about 7 blocks right below my farms. The dungeon was linked to a cave that opened out into a fully underground ravine, so that skeletons wouldn't stay around the spawner for too long. To make matters worse, the bottom of the ravine had an area where water was flowing in a such a way that skeletons were getting caught in the stream and forced into a pair of blocks. I dug down parallel to the ravine, created a little kill chamber (literally a spot at floor level 1/2 block high where I could hit their feet and they had trouble shooting me), and cleared out about 50 skeletons to the point where I could disable the spawner. The was easy enough.
Where I almost really screwed up is when I went to try and figure out how to clear the skeletons out at the bottom of the cave where they were caught. I created another small opening to kill about another 50 skeletons not caught in the water, but then I made the mistake thinking that the coast was relatively clear. When I poked my head around a corner to see the spot where the mobs were caught, I saw that the spot was totally glitching and I moved out of the way just in time to not get hit by 50-60 arrows. I decided to block the water stream to see if I could free them... HUGE mistake. Once the water was no longer holding them, 100-125 skeletons literally exploded out from the block that they were trapped. After running for my life, I figured out how to slowly coerce them out to where I could kill them in my little kill chambers.
After all that, I was still having lag issues and I could still hear skeletons so I figured that I didn't free all of them. Sure enough, the second spot where they were stuck still had water flowing into it. Instead of turning off the water, I just broke/set blocks up so that I could get into position to shoot them with arrows without them seeing me. It took me two full stacks of arrows killing another ~110 skeletons to finally kill all the rest. So yeah, after killing almost 300-350 skeletons (including two spots that were so dense with mobs that they were glitching like crazy), mobs almost immediately began spawning correctly again and the lag issues totally went away.
Some takeaways from this:
1) Mobs from spawners will not despawn because they have "persistence". I guess this is fine for mob farm purposes, but to me this seems like it is a very probable factor in why the mob cap fills up so quickly in some cases.
2) Mobs from spawners will contribute to your mob cap preventing other natural mob spawning. The official wiki is worded awkwardly on the issue, but I've tested this out on a separate world and confirmed this.
3) Spawners will continue to spawn if you are within 16 blocks (in any direction) even if you are over the mob cap (i.e. they contribute to the mob cap, but are not affected by it). Again, this seems like this is necessary for mob farms, but this also seems crazy to me.
4) Bedrock has no "entity cramming" restrictions and I found that this was a significant source of lag. I know that this is not new information, but that fact that it can happen in an unexplored cave without me ever knowing what was going on also seems crazy to me.
Anyway, that is my story. Hopefully, this will help out anyone else who is having mob spawn and/or lag issues.
Very well written, and ncie job on solving that.