Websites are displaying a 503 error after updating ea-php packages on CloudLinux systems.
A recent update has caused an issue that results in websites using PHP-FPM return a 503 error after updating the PHP versions.
At this time this issue can be resolved by updating the ea-php packages from CloudLinux's ea4-testing repository:
yum update ea-php* --enablerepo=cl-ea4-testing
CloudLinux plans on releasing the package on Tuesday, April 6th and it can take a week for the updates to reach all customers.