Best practices for deploying Java webapps with minimal downtime?

Question

When deploying a large Java webapp (>100 MB .war) I\'m currently use the following deployment process:

• The application .war file is expanded locally on the develop

Answer 1

Just use 2 or more tomcat servers with a proxy over it. That proxy can be of apache/nignix/haproxy.

Now in each of the proxy server there is "in" and "out" url with ports are configured.

First copy your war in the tomcat without stoping the service. Once war is deployed it is automatically opened by the tomcat engine.

Note cross check unpackWARs="true" and autoDeploy="true" in node "Host" inside server.xml

It look likes this

Now see the logs of tomcat. If no error is there it means it is up successfully.

Now hit all APIs for testing

Now come to your proxy server .

Simply change the background url mapping with the new war's name. Since registering with the proxy servers like apache/nignix/haProxy took very less time, you will feel minimum downtime

Refer -- https://developers.google.com/speed/pagespeed/module/domains for mapping urls