Ofbiz database with Amazon RDS

Hi,
   
    I have created the Amazon EC2 instance and MySQL database in Amazon RDS. I can able to connect EC2 through Putty and  DB through MySQL workbench. If i run with builtin derby DB its working fine, but instead of derby i want to connect to MySQL running in Amazon RDS. O modified the entityengine.xml to point to RDS end point as below

 jdbc-driver="com.mysql.jdbc.Driver"
 jdbc-uri="jdbc:mysql://ofbiz.c7rvbtvu58x8.us-east-1.rds.amazonaws.com/probiz123?autoReconnect=true"
 jdbc-username="ofbiz"
 jdbc-password="ofbiz"

When ofbiz started i can see the following error in the console.

Failure in findByCondition operation for entity [JobSandbox]: org.ofbiz.entity.GenericDataSourceException: Unable to esablish a connection with the database. (Unable to acquire a new connection from the pool). Rolling back transaction.
  [java] org.ofbiz.entity.GenericDataSourceException: Unable to esablish a connection with the database. (Unable to acquire a new connection from the pool)

I don't know where i am missing. Please suggest me.

Thanks,
Vinay