A while ago, we added a feature called “configuration presets”. These presets allowed you to define from within Scalr the configuration files for the services that you used, such as MySQL, Postgres, or Redis, and let Scalr handle the complexity of orchestrating file updates and service restarts.
There were a few limitations to this system, most notably that if you were unaware of this feature and made changes to a file such as my.cnf directly from the instance, Scalr would overwrite those changes (we considered this a good thing, but not everyone agrees).
So today we are releasing our improvements to our configuration file management system, making it more reliable, compatible with other management systems, and yes– realtime.
Here’s the workflow by which it works: when you click on the “Manage configuration” button from a Status page, Scalr will
- load the configuration file from the current master server (in the case of a replicated database, and to make sure we don’t overwrite your changes),
- let you edit or add any fields / lines and click ‘apply’,
- test your changes with a handy tool called configtest so no faulty settings are pushed (Scalr will also show you any faulty settings),
- if configtest isn’t supported, we restart the service with new config; if the service doesn’t restart, we rollback to your previous configuration and show you the error;
- restart the service, if needed, and
- push your changes to all nodes starting from the master, and finishing with the slaves.
Manage configuration directly from Scalr
Adding new values is dead easy.
Update was successfully applied on all two servers.
This new system has been updated for you to use with MySQL 5.5, Percona 5.5, Redis and PostgreSQL, and has very few (necessary for our baked-in automation) limitations, such as replication configuration. Apache, Nginx, and other are coming soon.
As usual, let us know what you think!
The Scalr “Realtime Hammertime” Team
If you enjoyed this read - why don't you sign up for email updates?
We'll let you know when we publish new blog posts, we won't spam you.