eCommerce stacksMagentoMagento 2TroubleshootingTroubleshooting Magento 2 optimised stack troubleshooting guide Traffic flow Who is logged into the server and what are they doing? Who has been logged into the server? Disk space Resource check - atop Logs Magento 2 log location PHP-FPM error log location Nginx log location MySQL error log Elasticsearch error log Server logs Varnish logs Command to check Nginx access logs Common Magento 2 issues PHP-FPM max children reached Database deadlocks Varnish 503 Permissions Find files not owned by "websiteuser" To change the ownership you can run the following command