Expected duration: 1 - 2 weeks I am facing a critical issue with my WordPress website hosted on a dedicated Kinsta server. Every time I send email campaigns via ConvertKit, the server experiences a significant spike in errors (500, 502, 503 & 525), leading to downtime and disrupted user experiences. This issue is persistent despite multiple attempts to address it with Kinsta support, and I need expert help to resolve it.
BACKGROUND -> Hosting: Dedicated Kinsta server (C2-standard-8) with 8 CPUs, 32GB RAM, and 20 PHP workers. -> Emails: Weekly campaigns to ~40,000 subscribers through ConvertKit.
Error Details: -> Errors predominantly occur immediately after an email campaign is sent. -> High traffic spikes from email tracking links (with query strings like ck_subscriber_id and utm_ parameters) overwhelm the server. -> Admin-ajax requests appear to be a contributing factor. -> Disabling caching for ck_subscriber_id cookies may be causing conflicts when combined with UTM parameters.
Additional details: -> Code snippet plugin previously caused errors (now resolved by deactivating it). -> Ongoing PHP worker and cron job timeouts have been reported in the logs. -> There is a large spike in cache MISS status when emails are sent. -> Attached is a chat thread with Kinsta providing fuller details. -> Here is an example of the URL string from our newsletter - https://www.conservation-careers.com/job/conservation-detection-nosework-seminar-2025/?utm_source=convertkit&utm_medium=email&utm_campaign=Unmissable%20opportunities%20in%20Conservation%20this%20week%20-%2015873629
OBJECTIVES Root Cause Analysis: -> Investigate the server logs, performance, caching and traffic behaviour during email campaigns. -> Identify specific conflicts or configurations causing the errors.
Optimization & Fixes: -> Resolve any issues identified in the Root Cause Analysis. This may include the following, -> Addressing conflicts between caching rules, UTM parameters, and ck_subscriber_id. -> Optimizing admin-ajax usage to reduce server load. -> Implementing efficient caching rules for email campaign links.
Testing & Monitoring: -> Monitor server performance during the next email campaign to confirm the issue is resolved. -> Provide a detailed report of changes implemented.
Recommendations: -> Suggest further performance improvements for WordPress on Kinsta hosting. -> Propose preventative measures for scalability during high-traffic periods.
Past Kinsta support actions: -> Temporarily disabled caching rules for ck_subscriber_id. -> Recommended enabling pre-caching for campaign URLs. -> Restarted PHP and adjusted NGINX settings to handle traffic better.
Deliverables: -> A detailed report of the issue and resolution steps. -> Implementation and validation of fixes to prevent recurrence. -> Recommendations for improving server performance and handling high traffic.
Requirements: -> Proven experience with WordPress performance optimization, particularly on Kinsta hosting. -> Familiarity with ConvertKit and handling query string conflicts in email tracking. -> Strong analytical and troubleshooting skills, especially with PHP worker management, caching, and admin-ajax optimization. -> Clear communication and ability to document solutions.
If you can help resolve this issue and enhance my server’s performance, please provide a brief outline of your approach and relevant experience.
Social Media Ad Designs Category: Adobe Illustrator, Photoshop, Branding, Graphic Design, Illustration, Logo Design, Social Media Marketing Budget: $30 - $250 USD
18-Jan-2026 05:04 GMT
Business development manager - IT INFRASTRUCTURE SALES Category: Account Management, Business Analysis, Business Development, Market Research, Project Management, Research Writing, Sales, SAP Budget: ₹150000 - ₹250000 INR
Business development manager - SAP SALES -- 4 Category: Account Management, Business Analysis, Business Development, Market Research, Project Management, Research Writing, Sales, SAP Budget: ₹150000 - ₹250000 INR
18-Jan-2026 05:00 GMT
Meta Ads for Music Reel Category: Advertising, Branding, Content Marketing, Digital Marketing, Facebook Ads, Instagram Marketing, Social Media Management, Social Media Marketing Budget: ₹1500 - ₹12500 INR
18-Jan-2026 05:00 GMT
Scrape Real Estate Licensee Data Category: BeautifulSoup, Data Collection, Data Extraction, Data Mining, Python, Scrapy, Selenium, Software Architecture, Web Scraping Budget: $30 - $250 CAD
18-Jan-2026 04:59 GMT
Webflow-to-WordPress Site Refresh Category: Graphic Design, HTML, SEO, Web Design, Web Development, Webflow, WordPress Budget: $250 - $750 AUD
Never Give Up Web App Category: AngularJS, Frontend Development, JavaScript, Node.js, PHP, React.js, User Interface / IA, Web Development Budget: $15 - $25 USD
150-Page PDF to Excel Conversion Category: Data Analysis, Data Cleansing, Data Entry, Data Management, Data Processing, Document Checking, Excel, PDF Budget: ₹12500 - ₹37500 INR
