A question we are asked fairly often: where exactly is my Kerika data stored?

The answer: some of it is in Amazon Web Services, some of it is in your Google Drive.

Here are the details: your Kerika world consists of a bunch of data, some of which relate to your account or identity, and some relate to specific projects and templates.

Your account information includes:

• Your name and email address: these are stored in a MySQL database on an Amazon EC2 virtual server.Note: this isn’t a private server (that’s something we are working on for the future!); instead, access is tightly controlled by a system of permissions or Access Control Lists.
• Your photo and personalized account logo, if you provided these: these are stored in Amazon’s S3 cloud storage service.These are what we call “static data”: they don’t change very often. If you have a photo associated with your Google ID, we get that from Google – along with your name and email address – at the time you sign up as a Kerika user, but you can always change your photo by going to your Kerika preferences page.

Then, there’s all the information about which projects and templates you have in your account: this information is also stored in the MySQL database on EC2.

• There are projects that you create in your own account,
• There are projects that other people (that you authorize) create in your account,
• There are projects that you create in other people’s accounts.
• And, similarly, there are templates that you create in your own account or in other people’s accounts.

Within each project or template you will always have a specified role: as Account Owner, Project Leader, Team Member or Visitor – Kerika tracks all that, so we make sure that you can view and/or modify only those items to which you have been given access.

Projects and templates can be Task Boards, Scrum Boards or Whiteboards:

• In Task Boards and Scrum Boards, work is organized using cards, which in turn could contain attachments including canvases.
• In Whiteboards, ideas and content are organized on flexible canvases, which can be nested inside each other.

With Whiteboards, and canvases attached to cards on Task Boards and Scrum Boards, all the data are stored in MySQL.

With cards on Task Boards and Scrum Boards:

• Files attached to cards are stored in your Google Drive,
• The title, description, URLs, tags, people and dates are stored in MySQL,
• Card history is stored in a Dynamo database on AWS.

So, our main database is MySQL, but we also use Dynamo as a NoSQL database to store history, and that’s because history data are different from all other data pertaining to cards and projects:

• The volume of history is essentially unpredictable, and often very large for long-living or very active projects.
• History data are a continuous stream of updates; they aren’t really attributes in the sense of relational data.
• History data is accessed infrequently, and then it is viewed all at once (again, an aspect of being a continuous stream rather than attributes).

It’s also important to note what we don’t store:

• We never store your password; we never even see it because of the way we interact with Google (using OAuth 2.0)
• We never store your credit card information; we don’t see that either because we hand you off to Google Wallet for payment.