How to diagnose this error even when running the simple command:
java -version
#
# There is insufficient memory for the Java Runtime Environment to continue.
# Cannot create GC thread. Out of system resources.
# An error report file with more information is saved as:
# /home2/ericlesc/code/java/c2/hs_err_pid23944.log
Check the amount of free memory you have:
free -m
total used free shared buffers cached
Mem: 28119 26643 1475 189 2391 15368
-/+ buffers/cache: 8884 19235
Swap: 5117 34 5083
Check the max number of user processes, make sure you are not over limit:
ulimit -a
ps -ef | wc -l
For me, the reason this happened was because PHP had consumed too much memory allocated to me on bluehost, and the way I was able to fix it, without restarting PHP or the server ( I can't ) was to take the public_html directory and rename it. And give it a minute for PHP to see the change, then rename it back.
A bug in the php engine itself. I found a clever way to give the PHP engine a swift kick.
(update Feb 2016) (I'm getting a spike of up-votes on this because Bluehost instance PHP engines are reserving all the memory and leaving none for the JVM. In their defense, PHP is evolving into an unholy rube Goldberg machine. Bluehost as a service is on the decline.