My organization asked my team to back up all of our data on Google App Engine, but we're not sure about the best way to do this. We looked into running a separate command for each kind of data that we need to back up. Is that the best way to go about this?
First, I think you mean the Google Cloud Platform, not Google App Engine. App Engine is just a platform as a service (PaaS) cloud, not something you can store data on. App Engine would work if you wanted to re-write your applications, but not if you need to simply back up your content.
That being said, if you want to back up your data to Google Cloud -- in particular, Google Cloud Storage -- it's important to determine what you want to be able to do with those backups. If your goal is to be able to hot-swap a database, then you'd want to set up some sort of read-only cluster or replica. In MySQL, for example, you'll want to set up either a "warm" or "hot" spare. A hot spare is a backup component that is put into service quickly when a primary component fails. Frequently used for replication and mirroring, a warm spare is a backup server that is turned on at intervals to receive updates from the server being backed up.
However, if you're just looking to restore to your existing system, or make sure that changes can be reverted, you'll want to do something like a MySQL dump, or an incremental backup system to back up data to Google Cloud -- or another cloud platform, such as Amazon Web Services. There are several available tools that do this, as well. And if you're working with regular file systems, you may want to check out Arq, as it supports Amazon Simple Storage Service (S3) and Google Cloud Storage.
Keep in mind that a cold storage service like this will require some significant downtime, if you need to restore after a catastrophic outage. However, it is significantly cheaper than having a warm or hot spare.
You may also want to look at backing up data that's in one cloud onto another cloud. For example, I have data automatically downloaded to S3 periodically from my databases in AWS, and that data is then copied over to both Rackspace and Google Cloud Storage. In the critical case that any files are completely lost on AWS, I can go to one of my other cloud storage services and manually restore that data.
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