508 Resource Limit Reached: causes and fixes
A 508 error means your hosting account hit its CloudLinux CPU or entry process limit. What triggers it, how to confirm the cause, and what to do to resolve it.
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A 508 Resource Limit Reached error means your hosting account has hit its CloudLinux resource limits-typically too many concurrent PHP processes running at the same time (Entry Processes limit), or sustained high CPU usage. The server is working, but it's throttling your account to protect other users on the shared server.
What is a 508 error?
CloudLinux enforces per-account limits on CPU, RAM, and concurrent connections. When your site exceeds these limits:
- New visitor requests are rejected with a "508 Resource Limit Is Reached" page
- Existing processes continue running until they complete
- The error clears automatically once load drops below the limit
This is not a server crash-it's a protective throttle. Other accounts on the server are not affected.
Check resource usage
- Log in to cPanel
- Go to Metrics → Resource Usage (or search for it)
- View the graphs for CPU, RAM, Entry Processes (EP), and I/O over the last 24 hours
- A bar consistently in the red or hitting 100% confirms the resource causing the issue
Common causes
| Cause | Indicator |
|---|---|
| Traffic spike | EP hits limit during a specific time period corresponding to a social media link, campaign, or viral content |
| Runaway WordPress plugin | CPU/RAM spikes all day; often a badly coded plugin running background tasks |
| Caching disabled | Every visitor triggers full PHP execution-no caching |
| Cron jobs firing too often | CPU spikes at regular intervals corresponding to cron schedule |
| WooCommerce without caching | High EP constantly on e-commerce sites without object cache |
| Brute force attack on wp-login.php | Massive EP spike from hundreds of login attempts per minute |
How to fix it
1. Enable page caching-the most effective fix. Install a caching plugin (WP Super Cache, LiteSpeed Cache, or W3 Total Cache). Cached pages are served as static HTML-no PHP execution, no EP impact.
2. Identify the heavy process-temporarily deactivate plugins one by one to find the problematic one. Check CPU usage in cPanel Resource Usage after each deactivation.
3. Block wp-login.php brute force attacks-add IP-based rate limiting via .htaccess or use a security plugin like Wordfence:
<Files wp-login.php>
Order Deny,Allow
Deny from all
Allow from YOUR.IP.ADDRESS
</Files>4. Reduce cron job frequency-if cron jobs are triggering load spikes, reduce their frequency or move heavy tasks to off-peak hours.
5. Optimize images and database-large unoptimized images increase I/O; a fragmented database slows queries.
When to consider upgrading
If you've applied caching and optimization but still hit limits regularly, your site has legitimately outgrown shared hosting resources. Options:
- Upgrade to a higher shared hosting plan-more CPU and EP allocation
- Migrate to Cloud VPS-dedicated CPU and RAM, no sharing, much higher ceiling
See: Shared hosting vs VPS comparison
Related: Resource limits | Disk quota exceeded-what to do | My website is loading slowly-what to check | Shared hosting overview
Still troubleshooting?
Use UnderHost tools for quick checks, or open a support ticket when the issue needs account or server access.
