BDS-19101Entering a nether portal causes 100% CPU every time
Any player entering a nether portal causes 4000% CPU (100% across all CPUs) usage. The server does not crash but recovers after a few minutes and the nether successfully loads. The problem is that it should not take 40 cores 2-3 minutes to load the nether every time and for every player. There are no errors in the log. This is an almost new server, the nether was created near the spawn.
Environment
Bedrock Server v1.20.62.03
Proxmox running linux container running docker container with 40 CPU cores
Plenty of SSD hard drive space
Plenty of RAM
Local gigabit networking
Thread count set to 0
Linked Issues
Created Issue:
One player entering a nether portal causes 100% CPU every time
Any player entering a nether portal causes 4000% CPU (100% across all CPUs) usage. The server does not crash but recovers after a few minutes and the nether successfully loads. The problem is that it should not take 40 cores 2-3 minutes to load the nether every time and for every player. There are no errors in the log. This is an almost new server, the nether was created near the spawn.
Environment
Bedrock Server v1.20.62.03
Proxmox running linux container running docker container with 40 CPU cores
Plenty of SSD hard drive space
Plenty of RAM
Local gigabit networking
Bedrock Server v1.20.62.03
Proxmox running linux container running docker container with 40 CPU cores
Plenty of SSD hard drive space
Plenty of RAM
Local gigabit networking
Thread count set to 0
One player entering a nether portal causes 100% CPU every timeEntering a nether portal causes 100% CPU every time
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relates to
relates to
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Would BDS-19101 describe your issue?
Our server is suffering from the same issue, as well as BDS-19101. Going through a portal can takes minutes to happen and the CPU usage spikes to 100% throughout that time. However once the nether eventually loads for the player CPU usage drops back to standard levels, however the world in all 3 dimensions is incredibly laggy. eating can take 4-5 attempts, blocks break and place eratically, and so on6
I can confirm this is still an issue as is BDS-19101
We are running a BDS server with 6 cores and it's maxing out or CPU on multiple cores when people go into the Nether.
I have this issue on my BDS as well and made a ticket about it last year here: BDS-19244
Interestingly, my server's issue is a bit different than the ones described here and at BDS-19101
I have the long nether loading time, which is alleviated when turning the render distance down. Also have chunks that refuse to load for 30+ seconds, which is present even with lowest render distance. However, eating and flying are normal (not laggy as described in this ticket). And server CPU usage does not spike to 100% but goes up to around 60% for the duration of loading.
Does this issue occur outside of BDS?
Not to my knowledge, however I did confirm that changing the thread count setting in the server config from 0 to 8 means that it only uses 800% CPU.
It also happening on 1.20.71
Pls fix that!
This problem has occurred on my server since many updates ago, probably 6 months or more. It seemed to get better with 1.20.64, slow to load through nether portals but did not crash the server. But since updating to 1.20.73, the crashes have started occurring again. Previous to 1.20.64, the crash would cause me to be at the entrance portal's coords in the dimension I was meant to be exiting to, so e.g. I go into portal in overworld at 100 64 2000, and end up on relog in the nether at 100 64 2000. Now when the server crashes it just takes me back in time by 30 seconds or so. CPU jumps to 700%, sometimes it will crash, other times is just takes ages to load as others see. Cannot replicate on single player world when use downloaded copy of the world and some portals perform better than others with varying levels of builds on either side of the portal. Server is hosted through Nodecraft, performance other than this portal issue is very good. Can answer questions if more info required.
This issue is still occurring on 1.20.81
Still occurring in 1.20.81.01
@greymagic27 This does not happen outside of BDS
can confirm that
server.properties:
client-side-chunk-generation-enabled=false
reduce time to load nether while entering portals.
overwise, sometimes (below 50% cases) - player can hear footsteps sounds for a minute or so, and then after loading to Nether can fall down to lava through blocks below the portal.
So, developers, server need more time to load - just add more seconds in a process, or make some subrouting to check memory loading.
High CPU = unzipping and reading too more chunks in one moment.
IMO
Thanks for the report. We will take a look.
If client-side-chunk-generation-enabled isn't set to "true" in the server.properties, it can take quite a long time for CPU performance to settle if render distances are high.
If you're experiencing this, please post a comment with whether you're using client-side-chunk-generation-enabled and mention what your max render distance setting is.
For what it's worth, my 1.21.1.03 BDS has the same issue, but a perf recording during the issue period where a client is nether portaling mostly shows that the CPU "usage" is actually just threads spin-waiting on lock contention.
client-side-chunk-generation-enabled=true
for me, but it shouldn't matter greatly in this particular portaling event, the surrounding areas on both sides of the portal have been mutated and stored into the leveldb already so need to be fetched from the server anyways rather than the client generating its own.
The performance is extremely bad at all of the client view distances I tried from 24-50, and entering the nether portal takes 20-30 seconds.
edit: I spun up my world on Windows Server 2022 and it has the same issue, it's not exclusively a linux issue.
Thank you for your report!
However, this issue has been temporarily closed as Awaiting Response.
Is this issue occurring also in newly created worlds?
This ticket will automatically reopen when you reply.
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Can confirm this is still an issue in version 1.21.2.02
Something to note; this issue not only occurs in brand new worlds, but also effects both Modded and un-modded Worlds.
Further update, I enabled client-side-chunk-generation-enabled on the server that I help run, with render distance set at 20, and this actually caused a lot more issues than when it was disabled.
Not only was the nether laggy, but the overworld starting lagging more, with chunks taking anywhere up to 30 seconds to load in.
After disabling the client-side-chunk-generation-enabled, the world goes back to only lagging when players go to the nether.
To add some data from my experience:
In all instances, all threads use 100% CPU.
Some interesting observations:
Steps to reproduce:
Expected:
Nether should load in a few seconds
Actual:
It now takes longer to load the Nether.
Sometimes the Nether appears, but you cannot interact with it, nor can you open your inventory. After a while (10 - 60 seconds), you are teleported back to the portal and you can now interact with the Nether.
I can confirm this issue occurs on Windows 11 23H2 running 1.21.3 BDS with client-side-chunk-generation-enabled=true.
I also experienced that after immediately loading into the Nether, the portal, all other structures, and excavating is reverted to the original Nether landscape. After 30-60 seconds, the Nether loads with the structures and excavating, and you "teleport"/snap to the portal.
Below is a link to a video showing the lag described above.
https://youtu.be/xxw9vdYZ3Bs
Dedicated Server Specs are below.
Device name minecraftserver
Processor Intel(R) Core(TM) i7-9700 CPU @ 3.00GHz 3.00 GHz
Installed RAM 32.0 GB (31.8 GB usable)
Thank you for the details and the repro video! We will take a look
client-side-chunk-generation-enabled true or false cause same issue with my server i'v 3 server with same nether bug on linux centos
Having the same issue. Teleporting to the nether causes 100% CPU usage (all cores) for a good 30 seconds. The other players in the overworld experience severe lag.
Confirming I still have this issue on v1.21.23. Running on a Debian 12 VM on ESXi with plenty of power. All of my server players have this issue. I’ve had this issue running the server on Windows 11, Windows Server 2019, and Debian 12. Tried multiple setting and VM adjustments as well as kernel level adjustments and nothing seems to make it better. Just massive usage every time entering the nether. I’ll have 48 GHz of CPU Usage pulled just by my Minecraft VM.
I have this issue on my BDS as well and made a ticket about it last year here: BDS-19244
Interestingly, my server's issue is a bit different than the ones described here and at BDS-19359
I have the long nether loading time, which is alleviated when turning the render distance down. Also have chunks that refuse to load for 30+ seconds, which is present even with lowest render distance. (server render distance is 24 by default, I tried turning it to 5, same result.)
However, eating and flying are normal (not laggy as described in the other ticket). And notably, server CPU usage does not spike to 100% but goes up to around 60% for the duration of loading.
My server is hosted by Bisect Hosting and the "client-side-chunk-generation" option is not present in my server properties file
Also experiencing this issue on the server I play on.