Frustrated by Magento? Then you’ll love
If you’re giving Magento’s new Marketplace feature a spin for the first time, you may be surprised to find that it requires you have your three Magento 2 cron jobs running.
There’s a few reasons for this. The first is a clever solution to the perennial PHP permissions problems when running commands and creating files as a web-user. It turns out the new Magento Marketplace web application never directly runs a unix command line command, or directly installs an extension. It simply schedules actions to take place, and there are various jobs in Magento’s crons that check for these scheduled actions.
The second, semi-related reason is Magento’s cron jobs write a number of hidden files to the var folder
$ ls -ld1 var/.*
//...
var/.setup_cronjob_status
var/.type.json
var/.update_cronjob_status
var/.update_queue.json
var/.update_status.txt
var/.maintenance.flag
var/.maintenance.ip
These files serve a variety of purposes. Some collect information about the Magento system, others signal to the Component Manager that it’s time to install a new extension, still other signal to Magento itself that its in maintenance mode, and should direct users to a maintenance page.
If you’re working locally on a development instance, you may not have your cron jobs configured. If you don’t want to configure cron jobs for a local dev instance, you should be able to run them manually whenever the Marketplace UI seems hung up (i.e. there’s a prolong ajax request constantly pinging the server).