Connection Pool Size for Fixed Thread Program

I have a fixed thread java program. It is implemented with Spring Integration and ActiveMQ. Fixed thread here means that program has multiple threads but the count of them in runtime don't change. Now I need to set connection pool size for it, So I should know:

1. How many threads it have
2. Which of them may connect to DB simultaneously.

For 1. I use visualVM tool.

• Can I use visualVM for 2. ? How?
• Has anyone another solu开发者_JAVA技巧tion for this problem?