Virgo-tomcat No task error log stop solution

Recently virgo-tomcat always for no reason down, using the following several methods to solve this problem, which method is effective, it is unclear ...
1. Delete the large log file below the Home/logs

2. Added java_opts= "-xms4096m-xmx4096m-xx:maxpermsize=512m-xx:survivorratio=4-xx to the. bash_profile file: PARALLELGCTHREADS=4-SERVER-VERBOSE:GC "

3. Configure the boot method from a child node under the node configuration of Jenkins by SSH, plus 2 configuration parameters:

Javapath:/home/platform/jdk1.6.0_13/bin/java

JVM Options:-XMS4096M-XMX4096M-XX:MAXPERMSIZE=512M-XX:SURVIVORRATIO=4-XX:PARALLELGCTHREADS=4-SERVER-VERBOSE:GC

Virgo-tomcat No task error log stop solution