Database Migration Starting & Done

Hello, just to let you know that today November 11, the database migration is starting …

Hello, just to let you know that today November 11, the database migration is starting. You can check this blog post for updates. Here are the steps I will be performing:

  1. test of the web application software upgrade. 09:55 UTC - Done.
  2. shutdown of the PHP processes to prevent update of the database. 09:56 UTC - Done.
  3. force the creation of a PostgreSQL WAL to have consistent backup. 09:57 UTC - Done. Now waiting for the log to be shipped to the warm standby. 10:00 UTC - Done.
  4. start of the warm standby as a new master. 10:04 UTC - Done.
  5. check that the new master is consistent. 10:21 UTC - Done.
  6. update the web application configuration to access the new master. 10:23 UTC - Done.
  7. start the PHP processes again. 10:25 UTC - Done.
  8. immediately clone the new master to have it log ship on another warm standby. 10:37 UTC rsync in progress
  9. 10:52 UTC - Done, with a warm standby in another datacenter nicely getting the updates from the master.

This is a bit of cascading but it will always keep several version of the database running and it will always be possible to revert to the original DB server in case of problem.

Last update: The system is now insanely more responsive, pleasure to use is back! If you notice anything unusual, please let me know as soon as possible.

Created: Fri 11 November 2011
Updated: Fri 11 November 2011
By Loïc d'Anterroches.

Tags: InDefero
Archives: 2011 / November
Fluid Phase Equilibria, Chemical Properties & Databases
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