MageMojo hosts thousands of stores and we see several issues that come up over and over across completely different sites.
Our number one cause for site down alerts is Magento’s maintenance mode. During module installation (or compilation/static file updates in Magento 2) Magento will be placed in maintenance mode. Maintenance can be disabled by removing a file named maintenance.flag from your Magento web root.
Under Magento 2 you should run the Magento command –
php70 bin/magento maintenance:disable
Maintenance mode will show your customers a 503, and it shuts your site off completely for purchasing.
Caching in Magento is critical for performance. Unless you are testing something or developing a site, the caches should always be enabled. There is generally no reason to leave the caches disabled on a live site ( and don’t develop on your production/live site either).
MageMojo monitors the page load times for our hosted stores, and a very large percentage turn out to be caused by the caches being completely off.
Developing on live
Never develop on your live site. Our support can create a copy of your site for you so you can develop without fear of losing your data or affecting customer traffic. Code changes should only occur on your live site after testing.
Enabling the compiler
Don’t enable the Magento 1.x compiler, it breaks sites more often than not. For Magento 2, the story is different and you should always use the compilation options and production mode.