Is there a way to run drush updb without going to maintenance mode

Question

I have a live site which runs on drupal 8. I am using drush 8.5.3 with the installation. Whenever I run drush updb the site automatically goes to maintenance mode. Is there a way to do this without going to maintenance mode. In simple words, can I use drush updb with my site running?

Answer 1

Actually, if you take a look at the drush code for updatedb command, you can find this piece of code in updateBatch() function:

$original_maint_mode = \Drupal::service('state')->get('system.maintenance_mode');
if (!$original_maint_mode) {
    \Drupal::service('state')->set('system.maintenance_mode', true);
    $operations[] = ['\Drush\Commands\core\UpdateDBCommands::restoreMaintMode', [false]];
}

For safety reasons, the drush command puts your site in maintenance mode during the update and then set it back online once it is completed. It prevents your users from accessing the website and generate possible conflicts within the database while it is updating.

There is a pretty clear explanation of this here

If you really wish to avoid the maintenance mode, though, you could run update.php directly from your website.

Answer 2

No. The critical path for drush updb is through:

• update_main()
• drush_update_batch()

Where drush_update_batch() toggles the maintenance mode state prior to processing the updates needed to be processed.

Theoretically, you could modify Drush itself or create your own Drush command that mimics the drush_update_batch() code without toggling maintenance mode. But a better question would be why? Maintenance mode is being set to prevent any problems while DB schema is being altered.