Heroku-like services for Scala? - scala

I love Heroku but I would prefer to develop in Scala rather than Ruby on Rails.
Does anyone know of any services like Heroku that work with Scala?
UPDATE: Heroku now officially supports Scala - see answers below for links

As of October 3rd 2011, Heroku officially supports Scala, Akka and sbt.
http://blog.heroku.com/archives/2011/10/3/scala/

Update
Heroku has just announced support for Java.
Update 2
Heroku has just announced support for Scala
Also
Check out Amazon Elastic Beanstalk.
To deploy Java applications using
Elastic Beanstalk, you simply:
Create your application as you
normally would using any editor or IDE
(e.g. Eclipse).
Package your
deployable code into a standard Java
Web Application Archive (WAR file).
Upload your WAR file to Elastic
Beanstalk using the AWS Management
Console, the AWS Toolkit for Eclipse,
the web service APIs, or the Command
Line Tools.
Deploy your application.
Behind the scenes, Elastic Beanstalk
handles the provisioning of a load
balancer and the deployment of your
WAR file to one or more EC2 instances
running the Apache Tomcat application
server.
Within a few minutes you will
be able to access your application at
a customized URL (e.g.
http://myapp.elasticbeanstalk.com/).
Once an application is running,
Elastic Beanstalk provides several
management features such as:
Easily deploy new application versions
to running environments (or rollback
to a previous version).
Access
built-in CloudWatch monitoring metrics
such as average CPU utilization,
request count, and average latency.
Receive e-mail notifications through
Amazon Simple Notification Service
when application health changes or
application servers are added or
removed.
Access Tomcat server log
files without needing to login to the
application servers.
Quickly restart
the application servers on all EC2
instances with a single command.
Another strong contender is Cloud Foundry. One of the nice features of Cloud Foundry is the ability to have a local version of "the cloud" running on your laptop so you can deploy and test offline.

I started working on the exact same thing as what you said a few weeks ago. I use Lift, which is a great framework and has a lot of potential, on top of Linux chroot environment.
I'm done with a demo version, but Linux chroot is not that stable (nor secure), so I'm now switching to FreeBSD jail on Amazon EC2, and hopefully it'll be done soon.
http://lifthub.net/
There are also other Java hosting environment including VMForce mentioned above.

If you are looking for a custom setup which also has the ease of deployment that heroku offers: http://dotcloud.com. They are invite only right now but I was given access in under three days. I am working on a Lift/MongoDB project there and it works well.

Off the top of my head, only VMForce comes to mind, but its not available yet. This will be a Java-oriented service, so that probably means you'll have to spend a wee bit of time figuring out how to package the app.
For more discussion, there was a debate about this in 2008.

I'm not entirely sure if it's really suitable or not, but people have deployed Scala applications to Google App Engine, for example http://mawson.wordpress.com/2009/04/10/first-steps-with-scala-on-google-app-engine/

Actually you can run scala on heroku right now. You don't believe it?
https://github.com/lstoll/heroku-playframework-scala
I'm not sure the tricks lstoll has used are legit but using the
new cedar platform where you can run custom processes and some
ingenious Gemfile hacking he has managed to bootstrap the Java
play platform into a process. Seems to work as he has a live
site running a test page.

Stax cloud service offers preconfigured lift project skeleton. Also, there is a tutorial on how to deploy lift project to appengine.

Related

Play framework in Scala deployment

I'm a Ruby developer, but I like Scala very much as well.
For Rails framework we have awesome tools that supports deployments like Capistrano automation tool and Puma/Unicorn servers. With simple cookbooks using Chef or Ansible I can easily setup my VPS and deploy Rails application there.
How does automatic deployment look like in Play framework? What is minimal required stack for developing and deploying Play applications? Are there any tools for automatic deployment? What are recommended application servers?
All you need to run a Play app is a JVM. Play is container-less. So deploying your Play app in production is as simple as running a script that invokes a fat jar with all the other required jars in the classpath.
$play dist should generate a zip file that contains everything you need to run the app.
You can use Ansbile to automate.
http://code.hootsuite.com/automating-our-scala-deploys-with-ansible-case-study/
http://www.ansible.com/press-release/ansibleworks-typesafe
To deploy Play Framework apps in AWS (Amazon) ec2 using Ansible playbook
As well as Chef.
https://github.com/gildegoma/chef-typesafe-stack
If you are happy to run on AWS, Boxfuse comes with native Play 2 support.
You can now simply execute boxfuse run my-play-app-1.0.zip -env=prod and this will automatically:
create a minimal AMI tailor-made for your Play 2 app
create an elastic IP
create a security group with the correct permissions
launch an instance of your app
All future updates are performed as blue/green deployments with zero downtime.
This also works with Elastic Load Balancers and Auto-Scaling Groups and the Boxfuse free tier is designed to fit the AWS free tier.
You can read more about it here: https://boxfuse.com/blog/playframework-aws
Disclaimer: I'm the founder and CEO of Boxfuse

Deploying Play 2.3 on production

I have developed a Scala/Play webapp and now I am trying to deploy it on production.
What is the recommended "best way" of doing that?
The documentation mentions only runnig it from play console, which does not seem very robust (in case of machine restarts etc).
There are apporaches to wrap the app into a war file and deploy on Tomcat7 (e.g. play2war), but they do not seem to be actively developed (e.g. there is only beta support for 2.3, the plugin is not available from maven repo etc).
What is the right way of doing this?
If you host the application on Windows then take a look at Yet Another Java Service Wrapper which wraps the application in a Windows service that will keep it running, even after restarts.
If you run it on Linux then take a look at Supervisord and Monit, which monitors the application and starts, restarts and stops it when needed.
See the following links for tutorials:
How do I run a Play Framework 2.0 application as a Windows service?
http://marcovanduijn.blogspot.nl/2011/08/run-play-framework-application-as.html
http://blog.fgribreau.com/2013/09/how-to-make-play-framework-2-work-with.html

Web framework with user-friendly desktop deployment?

I'm building a web app with Backbone.js (I'm not tied to Backbone yet though). I need a back-end framework only for persistence to a database via a RESTful API. However, I also need to able to deploy it as a 'desktop' app for off-line use, i.e. running a local server and launching a browser window, but I don't want users to have to start a server from the command line to run the application.
I can use SQLite as a database since it's only a single user application, it's just the framework that I'm stuck on. I have looked at the following:
Rails and Django: Default web servers are too flimsy, requires Ruby/Python and runs from the command line. I'm aware of the Bitnami stacks but at 99mb it's too big of a dependency and not exactly hidden from the user.
Sproutcore: Run from command line, also too bulky.
Pyjamas Desktop - Depends on MSHTML which I suspect limits my ability to use HTML5 features.
I'm leaning towards creating a Java app that starts a Scala/Lift server instance and opens a web browser, then sits in the system tray (kind of like WAMP). Is anyone familiar with a tool or framework built for user-friendly deployment as a standalone desktop app?
I do not know if PHP is an option for you? Then I would recommend phpdock.
web2py has a standalone deploy-to-desktop feature with no dependency on Python: http://web2py.com/books/default/chapter/29/14#How-to-distribute-your-applications-as-binaries
As Eydun said, phpdock is an option but it's commercially licensed .
I settled on using Java/Spring/H2/Hibernate/Jetty. I find that Jetty serves requests VERY quickly so the application looks real-time when launched in a browser. There is a tutorial on embedding the Jetty server here. I imagine it's quite trivial to build a GUI that launches the server and a browser.
Another Java option is to use the Play Framework, which may be more at home to those coming from a Django/Rails background. However, the documentation for "creating a standalone version of your application" for Play 2.0+ indicates that they have ditched using Java EE containers (Tomcat/Jetty) and WAR files in favor of running the JARs with the bundled copy of JBoss Netty, so it may take a bit of work to get it running the way you want it.
I would recommend the Play Framework approach if you're OK with using/learning Scala.

How to use Eclipse for remote debugging of a Google App Engine (GAE) application

Is there a way to debug (specifically step-through) a Google app engine application that has been deployed to the cloud. The reason I am asking is that there are certain things that either cannot be debugged locally or require work-arounds to test locally (eg. CRON Jobs).
Specifically I want to do this using Eclipse.
Update: as of 2015 it is possible to debug AppEngine Java applications if they run on Managed VMs. Also, the debugger is a web-based hosted debugger - no support yet for your popular IDE. See Cloud Debugger.
No, this can not be done.
One of the reasons why this most probably will never be available is that GAE is a distributed cloud system, where an "application" can have multiple instances running in parallel and there is no guarantee that consequent requests (e.g. a user session) would be served by the same instance. So there would be no way to know to which instance to connect debugger to.
You might want to star this acknowledged bug

Deploying an application without undeploying previous one and with no downtime?

I use Glassfish Java, and JSP over MySQL for my web applications. Many online people uses this web application and that web-site should not be down.
When I want to deploy a new war file, I should undeploy and deploy the new one for my application at server.
My question is that;
Is there any technology that doesn't need to undeploy my application and just change the appropriate classes so no need to redoploy it again?
There are java technologies that would allow you to replace classes on the fly (like JRebel). But since you're using Glassfish already, you should just start using clustering which is built into glassfish. You'll need either 2.1 or 3.1, as 3.0 does not support clustering. With a Glassfish cluster, you have a load balancer (Apache, Sun Web Server, hardware (Big IP, Coyote), etc) distribute the load among your cluster nodes. When you want to upgrade the app, you can technically do it one node at a time. Setting up the cluster is not the easiest thing in the world, but it is doable and it would get you some great benefits. You'll be able to scale the load by adding new hardware and even using Amazon (or whoever) cloud services. You'll be able to keep your site running even if the hardware fails on one of the nodes.
Personally I'm in the middle of converting from Glassfish 2.1 to 3.1. So far I like the management of the Glassfish 3.1 cluster much better, but I can't personally vouch for how it will run in production, though I have high expectations.
http://download.oracle.com/docs/cd/E18930_01/html/821-2432/gktqx.html#gktob
Jim is right, the best solution is currently to use a cluster and perform a manual rolling-upgrade.
But there is actually work ongoing to address your needs. We are working on a rolling-upgrade feature in a single standalone instance. To sum up in a nutshell (as the specifications have not been published yet), it will let you switch from an application version to another (see application versioning and the enable command) with no downtime. Stay tuned.