java.security.SecureRandom API.
This API uses /dev/random as a random number generator by default in some JREs. /dev/random accesses environmental noises collected from devices such as CPU temperature or keyboard timings to generate entropy. However, the virtual environment of CVMs makes it difficult to access such noises and generate entropy, causing cat /dev/random to block Tomcat and Hadoop from being started.securerandom.source=file:/dev/urandom in the original /etc/java-7-openjdk/security/java.security (use actual URL) to securerandom.source=file:/dev/./urandom to resolve this issue.Feedback