Hibernate for connecting tomcat container to mysql container

Hi, i’ve this problem.

My problem is: why, in Linux, using containers, there is so lot latency?

Ps: i’ve connected also the two containers via a user defined network (docker network create --driver=bridge mynet) , then i modified my hibenate.cfg.xml file pointing to localhost:3006/at_db (instead of mysqlphp:3306/at_db) but i have connection refused.

Why is so difficult porting my web-app from windows (xampp) to two separate containers? My teacher said me that probably it’s a DNS resolution problem, how what kind of problem and how to solve it?