Bukkit Minecraft server spontaneously quits when rendering dynmap

October 21, 2013 4k views
telkir
By:
telkir
Hello all, I am wanting to set up and run a CraftBukkit-based Minecraft server on a droplet. I have installed Java, set up FTP access to transfer in my existing files, and have gotten the server to actually run, so things are going pretty well - but I have hit a snag. The problem seems to be coming from the dynmap plugin. To save time in transferring the server files, I installed dynmap afresh, and I now want it to fully render the map tile images for the server's world. However, when I activate the render process, it will run for about 10-20 seconds and then the Minecraft server terminates with no error message. I have tried this on a 2GB droplet (using 1.5GB RAM for the Bukkit server) and then later on a 4GB droplet (using 3GB for Bukkit). Both times I hit the same problem, although it did take longer for the server to "crash" when trying it on the 4GB droplet. Am I perhaps hitting some limit with regard to CPU usage, which is in turn automatically killing the Bukkit server process?
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5 Answers
kamaln7 MOD October 21, 2013
Is there anything in the error logs? 
tail -20 /path/to/minecraft.log
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telkir October 21, 2013
Yes, I did check the log to make sure no error message was being caught there, and there's nothing useful. The last line is from dynmap as it starts the render process:

[code]2013-10-21 08:34:14 [INFO] Full render starting on world 'avalon'...[/code]

If I choose to not start a render the server will run indefinitely without problems.
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th October 22, 2013
I had the same problem a while back that I solved using more memory and 64bit java.
Last time I did a full render I used 5gb for bukkit and I had no crashes.

I start my server with following command, hope it helps:
screen -A -m -S "mc" java -d64 -Xms100M -Xmx5000M -jar -server -Djava.net.preferIPv4Stack=true -XX:+UseConcMarkSweepGC -XX:+DisableExplicitGC -XX:+UseAdaptiveGCBoundary -XX:MaxGCPauseMillis=500 -XX:-UseGCOverheadLimit -XX:+UseParNewGC -XX:+CMSIncrementalPacing -XX:SurvivorRatio=16 -XX:UseSSE=3 -XX:+AggressiveOpts craftbukkit-1.6.4-R.0.1.jar nogui
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droplet February 16, 2014
It's like the process is getting killed by some kind of manager to detect too-high cpu usage?? I have the same problem.

Process started t = 2014-02-16 16:17:39

~ 16:20:13 (t + 4mins) -->

>./start_server.sh: line 11: 1492 Killed java -Xmx1024M -Xms1024M -jar craftbukkit-1.7.2-R0.3.jar -o true
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kamaln7 MOD February 17, 2014
It's probably running out of memory. Try adding swap or upgrading your droplet: https://www.digitalocean.com/community/articles/how-to-add-swap-on-ubuntu-12-04.

Also try replacing -Xms1024M with -Xms512M.
How To Add Swap on Ubuntu 12.04
by Etel Sverdlov
Linux swaps allow a system to harness more memory than was originally physically available. Here's how to set up a linux swap file on Ubuntu 12.04
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