CODEWITHSUNDEEP
cloud-foundry
Kristof
Kristof

Reputation: 1734

Adding files for application to use on Cloud Foundry

For an application I'm converting to the Cloud Foundry platform, I have a couple of template files. These are basically templates for documents that will be converted to PDF's. What are my options when it comes to having these available to my application? There are no persistent system drives, so I can't just upload them, it seems. Cloud Foundry suggests for you to save them on something like Amazon S3, Dropbox or Box, or simply having them in a database as blobs, but this seems like a very curious work-around.

These templates will change separately from application files, so I'm not intending to have them in the application Jar.

Upvotes: 3

Views: 1954

Answers (1)

Scott Frederick
Scott Frederick

Reputation: 5155

Cloud Foundry suggests for you to save them on something like Amazon S3, Dropbox or Box, or simply having them in a database as blobs, but this seems like a very curious work-around.

Why do you consider this a curious work-around?

One of the primary benefits of Cloud Foundry is elastic scalability. Once your app is running on CF, you can easily scale it up and down on demand. As you scale up, new copies of the app are started in fresh containers. As you scale down, app containers are destroyed. Only the files that are part of the original app push are put into a fresh container.

If you have files like these templates that are changing over time and you store them in the container's file system, you would need to make sure that all instances of the app have the same copies of the template file at all times as you scale up and down. When you upload new templates, you would have to make sure they get distributed to all instances, not just the one instance processing the upload. As new app instances are created on scale-up, you would need to make sure they have the latest versions of the templates.

Another benefit of CF is app health management. If an instance of your app crashes for any reason, CF will detect this and start a new instance in a fresh container. Again, only files that were part of the original app push will be dropped into the fresh container. You would need to make sure that the latest version of the template files got added to the container after startup.

Storing files like this that have a lifecycle separate from the app in a persistence store outside of the app container solves all these problems, and ensures that all instances of the app get the same versions of the files as you scale instances up and down or as crashed instances are resurrected.

Upvotes: 6

Related Questions