The WordPress support guide for agency pros

Direct error tracking with WP_DEBUG

For starters, ensure your wp-config.php has the WP_DEBUG feature turned on. This tool is invaluable for uncovering hidden issues, but there’s more to it than just catching the obvious errors.

• Debug Logging: Enable the WP_DEBUG_LOG to keep errors logged in a file, allowing you to trace issues even if they’re intermittent.
• Script Debugging: Setting SCRIPT_DEBUG to true loads the non-minified versions of core CSS and JavaScript files, providing insight into script behavior on a granular level.
• Debugging Plugins: Consider plugins like Query Monitor or Debug Bar that provide detailed insights into database queries, hooks, and more.

Optimizing database performance

Next, we turn to the database, where performance can bottleneck. SQL profiling tools can identify inefficient queries that may be slowing down your site.

• Slow Query Log: Utilize your MySQL server’s slow query log to spot queries that take a longer time to execute than they should. These are dragging your client’s site down.
• Query Optimization: Make use of database tools like phpMyAdmin to fine-tune those sluggish queries, and get your site running more efficiently.
• Transients API: Cache your query results effectively, reducing the need for repetitive and resource-heavy database calls.

Child theme diagnostics

A misbehaving theme can be the source of many WordPress issues. Here’s how you can troubleshoot theme issues without compromising your customizations.

• Child Theme Diagnostics: When troubleshooting, switch to a WordPress default theme momentarily, and see if the problem persists, determining whether or not your custom theme is the problem.
• Review Custom Functions: Look into your child theme’s functions.php file for any custom code snippets that could be triggering issues.
• Performance Profiling: Use tools like GTmetrix or WebPageTest to pinpoint any slowdowns linked to your theme, allowing for targeted optimizations.

Strategic plugin management

Plugins can both extend functionality and introduce complications. Managing them well is key to a stable WordPress environment that doesn’t disrupt user experience.

• Staging Environments: Test plugins in a staging environment using tools like WP Staging or a local setup like LocalWP.
• Dependency Management: Be vigilant with plugins that rely on each other, which can often lead to conflicts if not managed correctly.
• Version Control: With a robust version control system like Git, you have a safety net, giving you the power to revert to earlier, more stable versions if updates cause issues.

Caching strategy for troubleshooting

Caching is essential for performance but can mask WordPress issues. Advanced cache handling can save you hours of debugging.

• Selective Cache Invalidation: Use version numbers for your scripts and styles to invalidate cache for updated files only, avoiding site-wide cache clearance.
• Cache Layer Inspection: Examine each layer of caching to accurately diagnose and fix issues specifically related to cached content.
• Object Caching: Fine-tune object caching with Redis or Memcached for dynamic parts of your clients’ site that regular page caching doesn’t address.

API and AJAX debugging

APIs and AJAX calls can fail silently, causing feature malfunction and harming your clients’ website. Here’s how to debug these complex issues.

• REST API Logging: Keep a log of REST API activity to identify and resolve failed calls efficiently.
• AJAX Request Monitoring: Use browser developer tools to monitor AJAX requests and responses, checking for unexpected status codes or responses.
• Security Nonce Checks: Make sure that your AJAX calls include a security nonce to prevent issues with user sessions and permissions.

Streamlined site migrations

Migrating WordPress sites is a task that even WordPress veterans approach with caution. Here are some tips to ensure migrations don’t turn into mayhem!

• Automated Migration Plugins: Use tools like Duplicator Pro or Migrate Guru for automated migrations, and then perform manual checks to make sure nothing was missed.
• Database Delta Deployment: For large sites, consider delta migrations, syncing only the changes rather than the entire database.
• URL Rewriting and Search Replace: Use search and replace scripts to correct serialized data, and ensure your .htaccess rules are migrated properly.

Backup management

A powerful backup system can be a lifesaver. Here’s how to make sure your backups are ready when you need them most.

• Differential Backups: Instead of full backups, consider differential backups to save space and time, backing up only what’s changed since the last complete backup.
• Staged Rollbacks: Use a plugin like WP Time Capsule to implement incremental rollbacks, restoring your site to the point just before the issue happened.
• Testing Backup Integrity: Regularly test your backups in a WordPress staging environment to ensure they’re comprehensive and reliable.