Was Magento 2 caching disabled?

Question

Recently, I worked a long time to find the problem cause running the website was too slow. Because of disabled the Magento 2 cache.

But I am not disabled manually or by command.

I updated the extension for this I have enabled the maintenance mode after completion again disabled the maintenance mode.

After the website ran too slow. After some time found that the Magento 2 cache is disabled.

'cache_types' => [
        'config' => 0,
        'layout' => 0,
        'block_html' => 0,
        'collections' => 0,
        'reflection' => 0,
        'db_ddl' => 0,
        'eav' => 0,
        'customer_notification' => 0,
        'full_page' => 1,
        'config_integration' => 0,
        'config_integration_api' => 0,
        'translate' => 0,
        'config_webservice' => 0,
        'compiled_config' => 0,
        'google_product' => 0,
        'vertex' => 0
    ],

My question is was Cache automatically disabled when we activate maintenance mode?

Please give a piece of brief information on what will happen when we activate maintenance mode? and also Cos and Pros.

Thanks.

Answer 1

Was cache automatically disabled activating maintenance mode?

Short answer: No, it shouldn't have.

Enabling maintenance mode shouldn't do anything to caches. It is only a mechanism to stop the bootstrapping of Magento during deployments or when you want to prevent users from getting to the website.

Magento Dev Docs - Enable or disable maintenance mode

What happens when activating maintenance mode?

When you activate maintenance mode, Magento will prevent the application from launching. There is a maintenance mode check in vendor/magento/framework/App/Bootstrap.php that calls $this->assertMaintenance(). It will throw an exception if maintenance mode is enabled, halting the running of the application.

This does what you would expect; Prevents users from browsing or shopping the website.

Pros/Cons to activating maintenance mode

Pros

• Prevents requests to the website from being fulfilled during Deployments / Deployment Rollbacks
• If you were performing a heavy upgrade/migration/feature deployment, keeping the site in maintenance mode would give you time to perform any manual steps before users start hitting the website
• Prevent new orders/transactions if a serious production site issue is happening and you need to firefight / troubleshoot

Cons

• Stops orders/transactions from coming in
• Stops users from being able to browse/interact with the website
• If activated long enough, effecting SEO crawls since all page requests will result in the maintenance mode page
• Users bouncing from the website since they are receiving maintenance mode page

Known Issues With Cache Automatically Getting Disabled

I'm not sure exact version numbers affected, but it is a known issue with certain versions of Magento that the caches get disabled during setup:upgrade and for whatever reason don't get re-enabled (I'll try to find the GitHub issues associated). For a few clients I've worked on this would happen during deployments and I'd have to make a note to explicitly log back into the server and enable caches after the successful deployment.

Links to check out related to cache disabling problem

Magento Github Issue - cache disabled after run "composer update" command

Magento StackOverflow - Magento 2.2.x cache disabled automatically

Magento Github Pull Request - Fix to Cache Disabling Issue

Magento Github Commit - Fix to Cache Disabling Issue