The WP ADA Compliance plugin inspects every link and file on the installed website. This process takes time and can use a lot of server resources. While the plugin is designed to mitigate common issues such as PHP settings that limit execution time and memory usage sometimes these meauses may not be enough. If you notice 504 or 500 server errors in your log files or on the error screen we suggest the following:
504 errors normally occur while scanning pages with a large number of links. If you see 504 server errors, increase the PHP max_execution_time to at least 300 and memory_limit to 256MB or 700MB for PDF scans. It may be necessary to increase the max_execution_time even further if 504 errors persist.
The deep scan process can us a lot of server resources when conducted from the report screen and on many budget friendly hosting packages server resources are severely throttled. If this occurs you will see 500 server errors displayed in your browser.
To verify that this has occurred, check your host’s resource usage statistics or contact your host to see if your account was limited during the affected time period. If available, access cPanel and under Metrics go to CPU and Concurrent Connection usage. This will show any recent faults. You may also be able to watch the CPU usage as you are scanning on the right side of the cPanel screen, under “Statistics”.
In order to successfully run a scan you will need to lower resource usage. On the settings page, under “Scan & Notification” settings: Lower the number of posts to scan each cycle to 5 or less.
Disabling the incorrect white space rule will reduce resource usage. This is a very uncommon issue and the process required to check for the issue tends to use a lot of resources.
Alternatively, enable cron scans under “Scan & Notification” settings and if not already done, setup a cron job in your cPanel. A variety of frequencies are provided to complete the scan in a timely manner. Cron scans use less resources and are a convenient solution to complete the scan process.