Play framework 2.1 application deployment - java

I've created my first Play application. Which is the most suitable deployment method for production? Should i copy the whole project to the production server and run play start? or should i make a war out of my application and deploy in tomcat / jboss? Which is the most recommended way? Getting confused with it comparing to its rails type of behavior. Note that this is supposed to be a big data application and also it may server loaded requests later on. So we are thinking of scalability, availability, performance aspects too. This application is decided to be deployed in a cloud.
Thanks.

As others have stated, using the dist command is the easiest way to deploy Play for a one-off application. However, to elaborate, I have here some other options and my experience with them:
When I have an app that I update frequently, I usually install Play on the server and perform updates through Git. Doing so, after every update, I simply run play stop (to stop the running server), sometimes I then run play clean to clear out any potentially corrupted libraries or binaries, then I run play stage to ensure all prerequisites are present and to perform compilation, and then finally play start to run the server for the updated app. It seems like a lot, but it is easy to automate via a quick bash script.
Another method is to deploy Play behind a front-end web server such as Apache, Nginx, etc. This is mostly useful if you want to perform some sort of load balancing, but not required as Play comes bundled with its own server. Docs: http://www.playframework.com/documentation/2.1.1/HTTPServer
Creating a WAR archive using the play2war plugin is another way to deploy, but I wouldn't recommend it unless you are giving it to someone who already has a major infrastructure built upon these servlet containers you mentioned (as many large companies do). Using a servlet containers adds a level of complexity that Play is supposed to remove by nature (hence the integrated server). There are no notable performance gains that I am aware of using this method over the two previously described.
Of course, there is always the play dist which creates the package for you, which you upload to your server and run play start from there. This is probably the easiest option. Docs: http://www.playframework.com/documentation/2.1.1/ProductionDist
For performance and scalability, the Netty server in Play will function very adequately to exceptional for what you require. Here's a reputable link showing Netty with the fastest performance of all frameworks and a "stock" Play app as coming in somewhere in the middle of the field, but way ahead of Rails/Django in terms of performance: http://www.techempower.com/blog/2013/04/05/frameworks-round-2/.
Don't forget, you can always change your deployment architecture down the road to run behind a front-end server as described above if you need more load balancing and such for availability. That is a trivial change with Play. I still would not recommend the WAR deployment option unless, like I said, you already have a large installed base of servlet containers in use that someone is forcing you to serve your app with.
Scalability and performance also has a lot more to do with other factors as well, such as your use of caching, the database configuration, use of concurrency (which Play is good at) and the quality of the underlying hardware or cloud platform. For instance, Instagram and Pinterest serve millions of people every day on a Python/Django stack which has mediocre performance by all popular benchmarks. They mitigate that with lots of caching and high-performing databases (which is usually the bottleneck in large applications).
At the risk of making this answer too long, I'll just add one last thing. I, too, used to fret over performance and scalability, thinking I needed the most powerful stack and configuration around to run my apps. That just isn't the case any more unless you're talking like Google or Facebook scale where every algorithm has to be finely tuned as it will be bombarded a billion times every day. Hardware (or cloud) resources are cheap but developer/sysadmin time isn't. You should consider ease of use and maintainability for deployment of your app over raw performance comparisons, even though in the case of Play the best performing deployment configuration is arguably the easiest option as well.

You don't need to use Play's console for running application, it consumes some resources and it's main goal is fast launch while development stage.
The best option is using dist command as described in the doc. Thanks to this, you don't even need to install Play on the target machine, as dist creates ready to use stand-alone application containing all required elements (also build-in server, so you don't need to deploy it with WAR in any container).
If you planning to use a cloud you should also check offers ie. from Heroku, or CloudBees, which allows you to deploy your application just by... pushing changes via git repository, which is very comfortable way, check the documentation's home, scroll down to links: Deploying to... for more details.

Related

Docker containerized monolithic application

We have just started a new project using Spring boot, which will have a monolithic architecture. There are some talks about using docker for containerizing the application.
Are there any benefits other than easier deployment across different platforms?
I would also like to understand whether auto scaling applies here. If yes, how?
Thanks in advance!
I just would like to add that lots of people tend to focus on the deployment, but the advantages for cyber security are enormous. The process isolation in the bounds of what could be seen as an advanced jail by itself could make the case for Docker.
Another advantage is the complement it provides for you CI/CD efforts and methodologies. By including the process of building imagens in the app building process, one gets better control of the overall process including a better view of the cycles.
Besides that, you also expand the number of ecosystems where you application can be easily installed and run. Added the support of a swarm or kubernets you got yourself access the the current hardened and managed could solutions.
With a stretch we can talk about scalability, if your image is meant to cooperate with replicas of itself, or if you put your containers were the hardware is itself elastic. Scalability also comes in to the discussion when you use means to control hardware usage in order to prevented services for competing for resources. This is also true if you do not have a cluster, as you can also manage hardware usage within a host.
Now it really depends on your needs and ninche. Some environments for instance would benefit in obvious ways even if scalability is not a concern. The inner networks you can create for instance is an excellent excuse to implement Docker, you get process isolation and network isolation inside a small host. Of course Docker is not meant to be a cybersec solution, but it adds up to the ones you already have.
I think it really depends on the scale of your application. The main benefit will certainly be ease of deployments and development, either on premise or on a cloud provider.
If you are running other applications along with Spring, like a database, cache server or other applications, you should have a look at docker-compose. It would really simplify not just the deployment of the Spring app, but also of all its dependencies.
Docker could help a lot also in case you plan to scale your application to multiple nodes, using docker swarm.
As for autoscaling, it is not really supported by docker out of the box, but you could achieve it with other tools on top of docker swarm.

Advice deploying war files vs executable jar with embedded container

There seems to be a current trend in java space to move away from deploying java web applications to a java servlet container (or application server) in the form of a war file (or ear file) and instead package the application as an executable jar with an embedded servlet/HTTP server like jetty. And I mean this more so in the way newer frameworks are influencing how new applications are developed and deployed rather than how applications are delivered to end users (because, for example, I get why Jenkins uses an embedded container, very easy to grab and go). Examples of frameworks adopting the executable jar option:
Dropwizard, Spring Boot, and Play (well it doesn't run on a servlet container but the HTTP server is embedded).
My question is, coming from an environment where we have deployed our (up to this point mostly Struts2) applications to a single tomcat application server, what changes, best practices, or considerations need to be made if we plan on using an embedded container approach? Currently, we have about 10 homegrown applications running on a single tomcat server and for these smallish applications
the ability to share resources and be managed on one server is nice. Our applications are not intended to be distributed to end users to run within their environment. However, moving forward if we decide to leverage a newer java framework, should this approach change? Is the shift to executable jars spurred on by the increasing use of cloud deployments (e.g., Heroku)?
If you've had experience managing multiple applications in the Play style of deployment versus traditional war file deployment on a single application server, please share your insight.
An interesting question. This is just my view on the topic, so take everything with a grain of salt. I have occasionally deployed and managed applications using both servlet containers and embedded servers. I'm sure there are still many good reasons for using servlet containers but I will try to just focus on why they are less popular today.
Short version: Servlet containers are great to manage multiple applications on a single host but don't seem very useful to manage just one single application. With cloud environments, a single application per virtual machine seems preferable and more common. Modern frameworks want to be cloud compatible, therefore the shift to embedded servers.
So I think cloud services are the main reason for abandoning servlet containers. Just like servlet containers let you manage applications, cloud services let you manage virtual machines, instances, data storage and much more. This sounds more complicated, but with cloud environments, there has been a shift to single app machines. This means you can often treat the whole machine like it is the application. Each application runs on a machine with appropriate size. Cloud instances can pop up and vanish at any time which is great for scaling. If an application needs more resources, you create more instances.
Dedicated servers on the other hand usually are powerful but with a fixed size, so you run multiple applications on a single machine to maximize the use of resources. Managing dozens of application - each with their own configurations, web servers, routes and connections etc. - is not fun, so using a servlet container helps you to keep everything manageable and yourself sane. It is harder to scale though. Servlet containers in the cloud don't seem very useful. They would have to be set up for each tiny instance, without providing much value since they only manage a single application.
Also, clouds are cool and non-cloud stuff is boring (if we still believe the hype). Many frameworks try to be scalable by default, so that they can easily be deployed to the clouds. Embedded servers are fast to deploy and run so they seem like a reasonable solution. Servlet containers are usually still supported but require a more complicated set up.
Some other points:
The embedded server could be optimized for the framework or is better integrated with the frameworks tooling (like the play console for example).
Not all cloud environments come with customizable machine images. Instead of writing initialization scripts to download and set up servlet containers, using dedicated software for cloud application deployments is much simpler.
I have yet to find a Tomcat setup that doesn't greet you with a perm gen space error every few redeployments of your app. Taking a bit longer to (re-)start embedded servers is no problem when you can almost instantly switch between staging and production instances without any downtime.
As already mentioned in the question, it's very convenient for the end user to just run the application.
Embedded servers are portable and convenient for development. Today everything is rapid, prototypes and MVPs need to be created and delivered as fast as possible. No one wants to spend too much time setting up an environment for every developer.

How do you develop/deploy BIG enterprise applications in java

I've been using java + spring on tomcat for the past 2 years and my app is getting notably huge. Start up time is now almost 3 minutes and it consumes a lot of resources during the development.
So I am interested in ideas how to make developing a software fun again. I've looked at Spring DM/Gemini blueprint to make it a modular but the experience was not convenient.
Now more modules are about to be added, thinking about developing it another web application and use Spring integration for messaging. Apparently, this will be a very painful experience to develop it on one desktop computer.
Has anybody any experience with cloud development? How do I improve all these time and resource consuming tasks? Will developing in the cloud help me?
It is very common problem with typical java+spring web apps. With age they start getting bloated and Context Loading starts becoming painful. I can suggest a few pointers to mitigate the issue, but only you will be able to judge best for you depending on the what exactly goes in your app.
Don't depend heavily on server while doing development. Write Unit tests and run them outside the servlet container. Spring has excellent support for this.
Split you business logic in Rest/Soap web-services (judiciously and carefully). This gives you freedom of developing and testing the UI independent of core business logic.
If using maven/gradle, try jetty plugin. It can keep scanning for changes and reloads the webapp automatically (I think tomcat plugin can do the same). It has ability to store session between restarts, so you are not affected by restarts. Please see this for more details How can I speed up Maven and Netbeans
[Paid Option] may try JRebel.
Use CI server, that keeps on integrating/testing/deploying your app, taking some load off your developers machines.
First, take care of the bottlenecks. They have a tendency to creep into projects as they grow. The original design has been compromised again and again to meet insane deadlines and now bloat has killed a once lively application.
Do not guess at the problem but use real data to determine what is making you app slow. Use a profiler such as jProfiler: http://www.ej-technologies.com/products/jprofiler/overview.html
Next, use what you've learned to make the new modules more efficient. The bottom line is changing technology is not a fix all, as all technologies can present bottlenecks. You must find the reason behind the problem and fix that.
Once you fix the bottlenecks, you could create some test projects on a new technology to see if it is faster, easier, does what you need. But, chances are just fixing the problems on your current stack is all that is needed.

How do I make a Java app self-update?

Problem: I have a standalone Java app (henceforth known as "the agent") that runs as a service on internal company servers. It acts as a remote agent for some central servers. As the agent gets deployed in more places, managing them is getting more complicated. Specifically: pushing updates is painful because it's a fairly manual process, and getting access to the logs and other info about the environments where the agents are running is problematic, making debugging difficult. The servers under discussion are headless and unattended, meaning that this has to be a fully automated process with no manual intervention, hence Java Web Start isn't a viable solution.
Proposed solution: Make the agent phone home (to the central servers) periodically to provide agent status and check for updates.
I'm open to other suggested solutions to the problem, but I've already got a working prototype for the "status and self-updates" idea, which is what this question is focused on.
What I came up with is actually a separate project that acts as a wrapper for the agent. The wrapper periodically calls the central server via HTTP to check for an updated version of the agent. Upon finding an update, it downloads the new version, shuts down the running agent, and starts the new one. If that seems like an odd or roundabout solution, here are a few other considerations/constraints worth noting:
When the wrapper gets a new version of the agent, there may be new JAR dependencies, meaning class path changes, meaning I probably want to spawn a separate Java process instead of fiddling with ClassLoaders and running the risk of a permanent generation memory leak, which would require manual intervention--exactly what I'm trying to get away from. This is why I ended up with a separate, "wrapper" process to manage the agent updates in my prototype.
Some servers where the agents are deployed are resource-limited, so any solution needs to be low on CPU and memory usage. That makes me want a solution that doesn't involve spinning up a new JVM and is a stroke against having a separate wrapper process.
The agent is already deployed to both Windows and RHEL servers, so the solution must be cross-platform, though I wouldn't have a problem duplicating a reasonable amount of the process in batch and bash scripts to get things rolling.
Question: As stated, I want to know how to make a self-updating Java app. More specifically, are there any frameworks/libraries out there that would help me with this? Can someone with experience in this area give me some pointers?
If your application is OSGi based, you could let OSGi handle bundle updates for you. It is similar to the wrapper approach you suggest, in that the OSGi container itself is "the wrapper" and some of it won't be updated. Here's a discussion on this
Different solution: use (and pay for) install4j. Check out the auto-update features here
No need for wrapper (save memory) or java web start (adds more restrictions on your application), simply let a thread in you application check periodically for updates (e.g. from cloud) and download updates if available, then code these two calls in you application:
launch a shell script (.sh or .cmd) to update your artifacts and launch your application after few seconds pause in the script(to avoid having two instances of your application at the same time).
Terminate your application (first instance)
The script can overwrite needed artifacts and re-launch your application.
enjoy !
Have a look at Java Web Start.
It is technology that's been part of Java since... 1.5? maybe 1.4? and allows deployment and install of standalone Java-based apps through a web browswer. It also enables you to always run the latest app.
http://www.oracle.com/technetwork/java/javase/overview-137531.html
http://en.wikipedia.org/wiki/JNLP#Java_Network_Launching_Protocol_.28JNLP.29
also see this question: What's the best way to add a self-update feature to a Java Swing application?
It appears as though Webstart is the only built in way to do this at the moment.

Avoid RePublishing the web application after Eclipse Shutdown

I am having my web application deployed on Tomcat5.5 and I use it in integration with eclipse 3.2.Each time I close the eclipse and restart it, I need to republish the application even when it hasn't been modified.
Is there a way to avoid this or any step I am missing ?
Go to Preferences->Server->Launching . Remove option 'Automatically Publish When Starting Server'
I think adij.wordpress.com correctly nailed this one. If you find that you're spending a lot of time waiting for Tomcat to restart as you develop your application, consider using Jetty instead. It'll restart in a fraction of the time Tomcat does and provides a full featured alternative that is ideal for agile development.
We use Glassfish (Tomcat based) with multiple EAR files and it's dog slow for development so each EAR project contains a Jetty launcher that simply fires up for the single WAR the developer is working on at the time. If you use IntelliJ this can be made automatic so that changes at any tier of the application can be instantly reflected into the currently running application in the time it takes to click onto the browser and refresh the page.
Do eclipse 3.3 or 3.4, or later versions of WTP behave the same way for you?
As this is a quite old question and still filed under unanswered, I'd like to broaden the scope with this answer:
I assume there is a reason for you to want to cut out republishing of your application that I don't know (other than the aversion against unnecessary work being done)
The only thing I can guess is that it takes a significant amount of time. For me the publishing time has never been an issue, but if they are for you, you might think about
increasing your memory (if swapping virtual memory slows republishing) - e.g. buying new RAM
optimize dependencies in your project, e.g. prepackage dependent projects if there's a huge number of them or create subprojects and depend upon them if there's only one huge project. (This assumes, that any of these factors slows republishing. I have not measured it)
does using Tomcat6 or glassfish help?
It might be, that not publishing is your issue but startup time. You might gain a lot by controlling that very tightly, e.g. starting services on demand after the webapplication has started. I know several applications that do some heavy work during startup (before they accept their first connection and before they pass control on to the next application startup that might do the same). I hate them. Usually such services get lots of swear words and finally their own web/application server. Having to restart one of these applications should at least not make all the other applications (and their users) suffer that are written with nice startup times in mind.
If your question is still an issue and you are still looking for a solution, please comment. What is your republishing time?

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