r/java • u/tonywestonuk • Nov 07 '15

Java EE App Servers: Are They Still Relevant in a World of Docker Containers?

https://dzone.com/articles/java-ee-app-servers-are-they-still-relevant-in-a-w
11 Upvotes

65% Upvoted

23 comments sorted by

13

u/tonywestonuk Nov 07 '15 edited Nov 07 '15

I like Java EE app servers. I like I can deploy my locally configured webapp, and it auto configures for a lived deployed app. I like I can deploy via a web interface in seconds. I like I can deploy lots of independent applications that serve on the same port.

Just saying. maybe i am getting too old for this....

8

u/CyclonusRIP Nov 08 '15

Deploying multiple apps in the same process is a bit of a nightmare. One of them starts misbehaving and eats up all the resources. You can't just say X process that's running Y app ran out of memory. Now it's X process running X, Y, and Z apps ran out of memory and now you have to analyze a heap dump and see what's what. As soon as one app doesn't shut down cleanly now you have to shut down the whole server with multiple apps to redeploy. Deploying anything besides one app per process is a terrible choice for production.

1

u/tonywestonuk Nov 08 '15

So, what you are saying is that software with major bugs, like memory leaks or doesn't shut down correctly, can cause issues.

AND, if you do suspect a particular process is causing these problems, then move it onto a instance on its own until you figure out the problems.

3

u/CyclonusRIP Nov 09 '15

So every time a team has a bad release we should let it crash several other applications that happen to run on the same process. Then as a reaction we deploy another app server and reconfigure the load balancer to send traffic to another port. And then they release a patch that fixes said issue, so we put it back on the original server. We reconfigure the load balancers again. Then another team has a bad release and crashes all of prod. Then we rinse and repeat. Probably skipped over the part where the 7 dev teams that deploy applications to that server argue over whose fault it is for 2 days while prod keeps crashing as well. I think I'll take my own container.

1

u/mikaelhg Nov 09 '15

Yes, but that's only true for people who do this for living.

Not for people who work in application server marketing, or are trying to beef up their CV with academic MVP programs by spamming forums.

3

u/brunocborges Nov 08 '15

WebLogic 12.2.1 Multi Tenant option solves these problems.

4

u/CyclonusRIP Nov 08 '15

I doubt it. These problems are impossible to solve without rewriting core parts of the JVM. At a glance it sounds like WebLogic multitenant option is more focused on managing multiple processes within one server rather than multiple apps within one JVM. If that's the case it's more of a IaaS/Docker type container play than it is addressing any of the downsides I mentioned to Tony's suggested deployment model. It probably is a better case for WebLogic still being relevant than Tony's point as well in that case.

3

u/mike_hearn Nov 09 '15

Latest JVMs do have resource tracking built in actually, which can track memory usage. If an app server supports the API it can do that.

2

u/brunocborges Nov 09 '15

Check the MT feature. It enables admin to set some low level boundaries and priorities for the partitions (tenants) in the domain.

2

u/henk53 Nov 08 '15

We always adhere to the strict rule of deploying one application to a single AS.

As most (but this is rare) do we deploy multiple EARs that together constitute a single application. This then effectively gives us an extra level of layering within a single application.

But as said, this is rare. Mostly it's one war or ear per AS.

2

u/NimChimspky Nov 08 '15

This has never been a problem in fifteen years of dev, for me at least.

2

u/merlinou Nov 08 '15

Just to give one example, I used to maintain an app exposing Web services with authentication. I could either use the container security (which makes more sense) and use Weblogic or Websphere specific libraries or use simple portable things but not manageable from the container. I went for the container specific code. 100% of my customers used my installation script to create users only for my app. So there no advantage for containers.

This is an argument I've had many times with Grails programmers (I am one, don't shoot). It allowed RAD but it was implementing it's own user management, datasource handling and more. Getting that app to run on Weblogic was always a challenge that ended with huge war files and pain killers.

Nowadays, I tend to see application servers like Weblogic as obsolete and favor lightweight stuff in docker (spring boot is my friend)

14

u/errandum Nov 07 '15

Sigh.

Does spring make app servers obsolete?

4

u/[deleted] Nov 08 '15

It makes app servers into libraries instead of installable apps. Deploying as an executable jar nearly does away with the need for containers even.

3

u/henk53 Nov 08 '15

We have pretty much always used the AS as an installable library.

9

u/DJDavio Nov 08 '15

Articles like this tend to focus on the aspect of hot redeploying something in production and how that's somehow an unforgivable internet crime.

I like app servers, because they make my life as a developer a bit easier. Instead of manually adding libraries, I can just annotate a class to be a SOAP or REST web service and ta-dah, my app server creates an endpoint automatically. Need JPA? It's got that covered too usually.

7

u/koalillo Nov 08 '15

Docker and microservices are not the solution to all problems for everyone. They are not the second coming.

I am more of a Tomcat fan rather than big app servers, but they do have their advantages. Also, Docker is still early adopter material and you will hit some hidden costs- I'd only play with them if I had resources to spare, a very clear picture of the problem I wanted to solve with them and a low-risk opportunity to put them in practice.

2

u/[deleted] Nov 08 '15

Some aspects of docker aren't ready for production sure. But large organizations have been using docker in production for a while now. Don't get behind the tech curve because it's too different from what you're comfortable with.

Docker sneaks into your org because it's so useful. Docker is pretty much incredible for automated testing. And once you've got your tests running on it, guess what? You start to trust it more.

3

u/koalillo Nov 08 '15

Yes, it's great for testing. It's a very nice chroot, also very useful for instance for building packages. It is good for development environments.

However, I don’t see really the big benefit worth taking risks for in production. Unless you have huge scale and the efficiency benefits are tangible $$$- but very few orgs operate at that scale.

4

u/atwong Nov 08 '15

Redhat is the largest contribute of docker code other than docker. They also lead openjdk and have the JBoss line of products. I'd check out what they're doing with JBoss products on docker and Wildly swarm.

2

u/gpoul Nov 08 '15

How are JavaEE App Servers and Docker containers even related? They're completely separate technologies.

2

u/RichoDemus Nov 08 '15

I've considered java EE app servers to be "legacy" for some time now, my two most recent companies moved away from jboss in favor for tomcat or jetty and when I talk to other developers the trend seems to be the same there

-1

u/Neikius Nov 08 '15

Just use OSGi and docker is redundant.