Activator Active Stocks starter application fails to run with java.io.IOException?

Question

I got the latest version of typesafe activator in Ubuntu 14.04 LTS. I also have the latest version of Scala/SBT etc etc.

When I start the Active Stocks application I get the following error java.io.IOException: User limit of inotify watches reached. I have no idea what this is ...

bravegag@zeus:~/code/activestocks$ ./activator
[info] Loading project definition from /home/bravegag/code/activestocks/project
[info] Set current project to reactive-stocks (in build file:/home/bravegag/code/activestocks/)
[reactive-stocks] $ ~run

java.io.IOException: User limit of inotify watches reached
    at sun.nio.fs.LinuxWatchService$Poller.implRegister(LinuxWatchService.java:261)
    at sun.nio.fs.AbstractPoller.processRequests(AbstractPoller.java:260)
    at sun.nio.fs.LinuxWatchService$Poller.run(LinuxWatchService.java:326)
    at java.lang.Thread.run(Thread.java:745)
[trace] Stack trace suppressed: run last compile:run for the full output.
[error] (compile:run) java.lang.reflect.InvocationTargetException
[error] Total time: 0 s, completed Nov 29, 2014 4:57:15 PM
1. Waiting for source changes... (press enter to interrupt)

Checking OS limits I see:

bravegag@zeus:~$ cat /proc/sys/fs/inotify/max_user_instances
128
bravegag@zeus:~$ cat /proc/sys/fs/inotify/max_user_watches
8192

Answer 1

not my soloution, but its always nice to have the anwser where it belongs:

$ sudo sysctl fs.inotify.max_user_watches=30000

will solve the problem imminently.

otherwise set the value in /etc/sysctl.conf by simply adding fs.inotify.max_user_watches=30000 (don't forget the newline)

References for what actually happens can be found here: http://www.la-samhna.de/samhain/manual/finotify.html

After that $ activator run worked as usual.