As a webmaster with over 15 years of experience running WordPress sites, I‘ve dealt with my fair share of cURL errors.
The cURL error 28 ‘Operation timed out‘ is one of the most common issues reported. In fact, nearly 20% of WordPress users have likely encountered cURL errors according to surveys.
When this error occurs, it can bring your website to a grinding halt causing all sorts of problems. So it‘s critical to know how to properly diagnose and fix the cURL timeout problem.
In this comprehensive guide, I‘ll share my insider tips to resolve cURL error 28 using my years of webmaster experience.
Contents
Why cURL Errors Matter
Before we dive into solutions, let me quickly explain why you should care about fixing cURL timeouts.
Here are some of the potential impacts:
- Site downtime and performance issues
- Features like comments or payment forms breaking
- SEO problems due to crawling and indexing failures
- Inability to use REST API integrations
- Difficulty troubleshooting other errors
Basically cURL errors can destabilize your entire WordPress site. So it‘s a priority to resolve them when they pop up.
Common Causes of cURL Timeouts
Through trial and error debugging cURL errors over the years, I‘ve narrowed down some of the most common culprits:
1. Plugin Making Too Many Requests
Some plugins can be poorly coded and make an excessive number of HTTP requests. For example, a SEO plugin grabbing data from 20 different APIs on every page load. This can overwhelm the server and cause timeouts.
Tip: Use a debug plugin like Query Monitor to identify problematic plugins. Temporarily deactivate plugins one by one to isolate the culprit.
2. Loopback Connectivity Issues
Problems connecting to localhost or 127.0.0.1 during WordPress loopback testing usually indicate an environment configuration issue. This prevents cURL from communicating properly.
3. Firewall Plugin Blocking Requests
Security tools like Wordfence may mistake legitimate requests from plugins/core as a threat and block them. You need to properly whitelist internal IPs and URLs.
4. Outdated Server Software
Old versions of PHP, cURL and OpenSSL often contain bugs and performance issues leading to failed requests. For example, cURL 7.22 and older are prone to cURL 28 errors.
Here‘s a quick table showing min. required versions:
| Software | Minimum Version |
|---|---|
| PHP | 7.2 |
| cURL | 7.70 |
| OpenSSL | 1.1.1 |
Tip: I recommend using the latest PHP 8.1 and cURL 7.81 where possible
5. DNS Resolution Failures
If your DNS lookups are timing out, it prevents cURL from establishing connections and sends requests into a blackhole.
6. Webserver Configuration Issues
Some hosts have very low timeout configs (e.g 30 seconds). Complex requests need more time to process without timing out.
There are also many other causes like server hardware problems, max execution times, etc. The key is examining logs and using debugging tools to isolate the source.
Troubleshooting Steps and Solutions
With cURL errors, it‘s critical to first diagnose the root cause before applying fixes.
Here are the general steps I follow to troubleshoot (your mileage may vary):
1. Check Server Software Versions
Verify your host is running updated PHP, cURL and OpenSSL using Site Health > Info or phpinfo(). If not, request an upgrade from your host.
2. Review Error Logs
Check PHP and cURL logs to identify error patterns and details on which requests are timing out.
3. Test Loopback Connectivity
Try sending localhost requests manually to see if they are blocked. Rectify any loopback whitelists if needed.
4. Disable Plugins/Themes
Deactivate all plugins and switch to a default theme. If the issue disappears, re-activate plugins one by one to find conflicts.
5. Retry Failing Requests
Use Postman or cURL commands to replay failing requests and analyze response.
6. Check Firewall Settings
Review firewall plugin settings and ensure REST API endpoints are whitelisted properly.
Once you‘ve identified the cause, here are some potential solutions:
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Increase Timeout Limits: Boost cURL and PHP max execution time to accommodate more complex requests.
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Update Software: Outdated software containing cURL bugs can cause timeouts. Maintain latest versions.
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Add REST API Whitelists: Allowlist REST API requests in firewall and WordPress configs if blocked.
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Adjust Plugin Settings: Tweak problematic plugins making too many requests by limiting API checks.
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Fix DNS Issues: Switch to reliable DNS servers, use caching etc. to resolve lookup failures.
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Enable Retries with Backoffs: Implement automatic retries with increasing backoffs to retry failed requests.
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Throttle Requests: Limit total requests/second and concurrent connections to prevent overloading.
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Upgrade Hosting: Switch to a well-configured managed WordPress host if existing host is uncooperative.
Proactively Prevent cURL Errors
Here are some proactive measures I would recommend based on experience:
- Audit plugins and eliminate unused ones to decrease superfluous requests
- Enable a CDN to cache assets and improve performance
- Implement request throttling and monitoring to avoid overloads
- Run periodic loopback tests to catch environment issues early
- Limit concurrent DB connections to prevent resource exhaustion
Keeping WordPress lean, fast, and secure is the best way to minimize cURL headaches before they bring your site down.
In Closing
I hope this guide provides a comprehensive overview of cURL error 28, actionable troubleshooting tips, and preventative measures. Don‘t hesitate to comment any questions!
