On Monday, 19 June 2017 8:30:46 AM AEST Arjen Lentz via luv-main wrote:
time when we have 2 separate instances of Drupal and I don't want anyone to make changes to the old one that get lost.
Re the backend MySQL storage, you make the new MySQL instance a slave of the old one. That way nothing can get lost. We've find this many times with large systems. No outage and no data loss.
Thanks for the suggestion, it's something to consider when migrating a system that has a non-trivial amount of writes. But when dealing with a system that has an average of less than 1 write of actual data per week it's not needed.
By the way, things tend to actually work out better in many respects to NOT have frontend and database on the same VM. This is generally the first step we take in creating resilient and scalable environments.
Well if you want some sort of HA scheme that may be the case. But if your service is small enough that the amount of effort required to make a HA system more reliable than a single system isn't viable then a single VM.
There are many disadvantages to combining all services onto the same box. In vm hire terms, it may also be cheaper to use more smaller instances as the pricing model favours those.
https://www.linode.com/pricing For Linode the pricing scales fairly linearly with size for most common sizes and other hosting companies have similar schemes. -- My Main Blog http://etbe.coker.com.au/ My Documents Blog http://doc.coker.com.au/