Tomcat测试和生产环境

Question

What is the best design to have many enviroments for one web-app? Is it better to have multiple tomcat instances or multiple web-app instances deployed on one Tomcat server?

Answer 1

If one server can handle the load, I would said it's better to have just one Tomcat instance and deploy web-app multiple times if necessary.

This way:

1. You'll have only one server to take care of (secure, administer, backup).
2. You share hardware resources among applications (RAM, DISK, CPU)

Answer 2

Ideally, you should keep all production code on a completely separate environment as much as possible just to avoid mistakes and for security reasons.

Depending on your resources and team size, say for example, you have an enclave for production: web server, database, mail server. This should have rules to disallow any development resources from access production resources and vice versa. If your dev resources have been compromised or you run a script going to the wrong resource, there would be a layer of protection for that.

Yes, this is all inconvenient, but it could save you from having big headaches in the long run.

Answer 3

The idea of deploying the same web-app several times in order to reduce administration burden is good.

But in my opinion, this isn't an acceptable solution : suppose you deploy a web-app twice. Once for a TEST environment and a second time for a PRODUCTION environment. The web-app may encounter exceptions/errors (typically, memory-related issues) that may lead the whole Tomcat server to crash. In such a situation, problems that were encountered in one environment would cause the other one to be unavailable.

Therefore, I would rather install as many Tomcat instances as different environment.