title: Multi-WAR tomcat vs Docker containers
body: <p>I'm wondering if a Docker solution is faster and more memory efficient than my current Tomcat deployment. I will explain both solutions.</p>
  
  <p>The current:
  I have a Tomcat server with about 20 WAR's deployed. The WAR's are Spring Boot applications. It takes up a lot of memory and boottime and money too. </p>
  
  <p>The docker alternative:
  The alternative I'm thinking about is a docker host with 20 docker containers, one for each app. It seems Spring recommends using JAR's on JDK images.</p>
  
  <p>Now, does Docker, or containerization in general, improve memory and speed? </p>
  
  <p>One improvement I am expecting is that applications can start in parallel. This will hopefully speed up boot-time (assuming multi-core hardware). Am I right here?</p>
  
  <p>Secondly I'm wondering which approach will handle memory most efficient.
  What happens when I have multiple WAR's, sharing the exact same dependency? Will Tomcat reuse dependency memory for that? And will Docker? </p>