Java EE application deployment on Amazon EC2

Question

We have a Java EE application (EAR file deployed on JBoss, MySQL, MongoDB) which we would like to deploy on an Amazon EC2 instance. I have several questions regarding deployment best practices.

1. What is the most commonly used Linux AMI which we can rely on for a robust deployment (There are so many Linux variants, and I am not sure which AMI is commonly used, is it Fedora, CentOS, Red Hat, SUSE ...)
2. How do we handle production upgrades (EAR file modifications or schema upgrades). Are there any tools which are available to handle this installation or rollback of these changes.
3. What kind of data backup capability is available for the database?
4. Should I rely on Amazon RDS for MySQL support?
5. How should I handle support for MongoDB?

This is the first time, I am hosting an web-app and would appreciate some inputs on how to manage the production instance.

Answer 1

If you can live with deploying your Java EE application on TomEE instead of JBoss, Boxfuse does what you want.

For you Java EE application you literally only have to execute (TomEE uses war files instead of ear files):

boxfuse run my-tomee-app-1.0.war -env=prod

This will

1. Create AMI containing TomEE and your application ready to boot
2. Create an Elastic IP or ELB
3. Create a security group with the correct ports defined
4. Create an auto-scaling group
5. Launch your instance(s)

Any subsequent update will be done as a zero downtime blue/green deployment.

More info: https://boxfuse.com/blog/javaee-aws

Answer 2

1. I agree with Mark Robinson's answer: Use whichever Unix variant you're most comfortable with. It may pay to pick one with decent cloud support. For my site I use Ubuntu.

2. I have a common image which is the base of every version deploy I do. I have www.mysite.com pointing to an Elastic IP so I can decide which instance it goes to. The common image has all the software I need installed (Postgres/Postgis/Tomcat/etc) but the database and web server data folders and symlinked to Elastic Block Store (EBS) instances.

   When it comes time to do a deploy I start a new instance up, freeze and snapshot the EBS volumes on production and make new volumes. I point my new instance at the new volumes and then install whatever I need to onto that. Once I've smoke tested everything successfully I can switch the Elastic IP to point to the new instance and everything keeps on going.

   I'll note that I currently have the advantage where only I can modify the database; no users can. This will become a problem shortly.

3. If you use the XFS filesystem on top of the EBS volume then you can tell XFS to freeze the file system (so no updates happen) then call the EC2 api to snapshot the volume then unfreeze the file system. The result is that the snapshot is taken quickly and sent to S3. I have a nightly script which does this.

4. If RDS looks like it will suit your needs then use it. Amazon is building lots of solid tools quickly and this will ease your scalability issues if you have any.

5. I'm sorry, I have no idea.

Answer 3

What is the most commonly used Linux AMI which we can rely on for a robust deployment (There are so many Linux variants, and I am not sure which AMI is commonly used, is it Fedora, CentOS, Red Hat, SUSE ...)
How do we handle production upgrades (EAR file modifications or schema upgrades). Are there any tools which are available to handle this installation or rollback of these changes.
What kind of data backup capability is available for the database?
Should I rely on Amazon RDS for MySQL support?
How should I handle support for MongoDB?

1. Any Linux AMI will do the job, what you need is a JRE only. (assuming development work not required). If you need to monitor the JVM behavior then get JConsole installed.
2. Easiest and painless way is to SSH into the local home directory, transfer the updated class file/EAR file (depends the number of changes applied) and copy and replace into the Tomcat deployment directory, restart apache. (make sure you tested locally before upload to production).
3. Depends on which database you are using, if you are using MySQL then just do scheduled backup that writes to your home directory so that from time to time you could SSH in and download a copy for backup purpose.
4. I would not consider reply on Amazon RDS for MySQL support due to 2 reasons: MySQL is small enough and manageable, and also I would want to have total complete control of the database and why pay for more when you can do it yourself FOC?
5. The usage of MongoDB should be align with the purpose of your application and benefits you gain from that. I would recommend you use MongoDB for static data retrieval like state, country, area etc... where MySQL to be use for transaction data only.

Answer 4

Good question!

1) I would recommend going with whatever Linux variant you are most comfortable with. If you have someone who is really keen on CentOS, go with that. Once you have selected your AMI, take it and customize it by configuring how you want it. Then save that AMI as you base-layout. It will make rolling out new machines much easier and save your bacon if EC2 goes down.

2) Upgrades with EC2 can be tres cool. Instead of upgrading a live system, take your pre-configured AMI, update that and save that AMI as myAMI-1.1 (or whatever). That way, you can flip over to the new system almost instantly AND roll back to a previous version in case something breaks. You can also back-up DB instances to S3. It's cheap at about $0.10/GB/Month.

3) It depends where you are storing your DB. If you are storing it on your EC2 instance you are in trouble. The EC2 instances have no persistence storage. So if your machine crashes, you lose everything. I'm not familiar with Amazon DB system but you should also look into Elastic Block Store. It's basically an actual hard-drive you can write to. When you want to upgrade your schema, do a full DB dump to S3 and then do an upgrade of your actual schema. If something goes wrong, you can pull the previous version out of S3.

4) & 5) I have never used those so I can't help you.