How to run `play` in a 512M vps -- it reports `Could not reserve enough space for object heap`? - startup

Question

I'm running play2 on a 512M vps.
It can create a new app:
play new test
But can't start that test project:
cd test
play
It reports such an error:
[freewind#289144 test]$ play
Error occurred during initialization of VM
Could not reserve enough space for object heap
Could not create the Java virtual machine.
[freewind#289144 test]$
After some research, I found play2 will invoke play-2.0/framework/build, and build has following settings:
I tried to modify the play-2.0/play shell, from:
java ${DEBUG_PARAM} -Xms512M -Xmx1536M -Xss1M -XX:+CMSClassUnloadingEnabled
-XX:MaxPermSize=384M -Dfile.encoding=UTF8 -Dplay.version="${PLAY_VERSION}"
-Dsbt.ivy.home=`dirname $0`/../repository -Dplay.home=`dirname $0`
-Dsbt.boot.properties=`dirname $0`/sbt/sbt.boot.properties
-jar `dirname $0`/sbt/sbt-launch.jar "$#"
We can see that the Xms is 512M, the vps hasn't enough memory for it.
So I change it to:
java ${DEBUG_PARAM} -Xms112M -Xmx300M -Xss1M
-XX:+CMSClassUnloadingEnabled -XX:MaxPermSize=84M -Dfile.encoding=UTF8
...
This time, the error message is changed:
Error occurred during initialization of VM
Cannot create VM thread. Out of system resources.
What should I do?

Answer 1

Assuming you're running the Sun Hotspot VM, run it like this:
_JAVA_OPTIONS="-Xmx384m" play <your commands>
And you'll get what you need. When the VM launches, it includes the contents of the _JAVA_OPTIONS environment variable along with any other command-line Java options you specify. You'll know it was picked up because you'll see the following message on your console:
Picked up _JAVA_OPTIONS: -Xmx384m
The shell command above defines the variable only for execution of the rest of the shell command. If you wanted to make it more durable, you could say something like
export _JAVA_OPTIONS="-Xmx384m"
and put that in .bash_profile, or .profile, etc.
The _JAVA_OPTIONS environment variable is poorly documented, and I'm not sure how widely it is supported, but I'm pretty sure it works on Linux, BSD* (like Mac OS), and...I don't know what else.

Answer 2

I faced the same issue but I found the reason and the solution.
It is a java parameter in play. I do a simple check:
java -Xms512M -Xmx1024M -Xss1M -XX:+CMSClassUnloadingEnabled -XX:MaxPermSize=256M -version
This does not work, but
java -Xms512M -Xmx1024M -Xss1M -XX:+CMSClassUnloadingEnabled
does work! and
java -Xms512M -Xmx512M -Xss1M -XX:+CMSClassUnloadingEnabled -XX:MaxPermSize=256M
works too.
You have to modify the build.bat as I did: on maximum mem size or change the maximum permanent size.

Answer 3

I build and develop locally. I then run "play dist" to create a distribution which contains a start script. I deploy to my 512MB VPS using Fabric and do not have any memory issues.

Answer 4

Another way is to use the following command (it works when you dont use play dist but have the framework installed on the server aswell, maybe it works with the standalone package too but I have not tested it):
play "start 6000" -Xms64m -Xmx128m -server
the "start 6000" will start the server listening on port 6000.

Answer 5

play stage && target/start -Xmx384m