backup.utf8

What should be backed up?


Description: 
   for backup and restore we were thinking about using the dump procedures provided by mongodb and mysql, respectively.
   then we would use the backups from our IT department to backup the dumps.
   for restore we would use the restore procedures provided by mongodb and mysql, respectively.

Questions:
   - Do you see anything wrong with the proposal ?
   - If so, could you give a few pointer about how to attack it?

Answer:

This seems completely reasonable. When there is no pre-existing architecture, I usually
recommend to externalize db+backup, as this part is not specific to edX, so it can be
worth letting someone else worry about it. Ie, when the installation is on AWS, using RDS
for MySQL and mongolab for the mongo databases, and using their backup services to save
them.

However, in your case, it makes sense to use your IT department backup capabilities. If
they also offer to run MySQL/Mongo, that might be worth taking advantage of it, similarly
as you would from RDS/mongolab. If they are already running instances for other projects,
you might also benefit from existing backup procedures.

If not, and you want to do the backups, you will need dump the contents of the different
databases. The tools which will allow you to do this are:

* `mysqldump`: http://dev.mysql.com/doc/refman/5.1/en/mysqldump.html
* `mongodump`: http://docs.mongodb.org/manual/reference/program/mongodump/

Here are some sample command line calls - to adapt to your case:
```
$ mysqldump -u root --single-transaction $db > /opt/backup/sql/$db.sql
$ mongodump --db $db --out /opt/backup/mongodump/$db
```

In all cases, make sure you're correctly setting up databases to point to external
servers, don't let the default `edx_sandbox.yml` values which use the `edxlocal` role to
setup local database servers on the same instance. You basically want to work with the
assumption that you should be able to destroy your instances at any time without losing
anything. Not only this ensures that you backup everything that should be, it also ensures
that you won't make changes directly on the instances, but rather always from the ansible
playbooks. This way you don't accumulate entropy on the VMs, and all changes to the servers
are versioned with git (which you will also need to backup those repos, if you don't use 
github).

The best way to ensure this discipline, and make it easier to follow, is to setup an 
automated build. It would automatically recreate the instance from scratch every time 
a change is made from one of the repositories.