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.
Influencer Marketing Strategy for Mobile App Growth Category: Android, Content Strategy, Digital Marketing, Influencer Marketing, Internet Marketing, IPhone, Marketing Strategy, Mobile App Development, Social Media Management, Social Media Marketing Budget: $250 - $750 USD
31-Mar-2026 10:04 GMT
LED Ad Design + WhatsApp Leads Category: Advertisement Design, Banner Design, Facebook Ads, Graphic Design, Instagram Marketing, Lead Generation, Poster Design, Social Media Marketing Budget: ₹1500 - ₹12500 INR
31-Mar-2026 10:04 GMT
Client Portal Development and Data Migration Category: API Development, App Design, App Development, Cloud Computing, Data Management, Database Design, Microsoft Access, Mobile App Development, MySQL, PHP Budget: £10000 - £20000 GBP
31-Mar-2026 10:03 GMT
Candy Wholesale Customer Service On-Demand Category: Customer Experience, Customer Service, Customer Support, Email Handling, English Tutoring, Inventory Management, Time Management Budget: $2 - $8 USD
Modern Flat Interior Design Category: 3D Modelling, 3D Rendering, 3ds Max, AutoCAD, Interior Design, Lighting Design, SketchUp, V Ray Budget: ₹1500 - ₹12500 INR
31-Mar-2026 09:59 GMT
Build Advanced DSAV Company Website (.com) Category: CSS, Graphic Design, HTML, JavaScript, Next.js, Web Development, Web Design, Website Optimization, WordPress Budget: ₹900 - ₹1500 INR
Rédaction Articles Cuisine Malgache Category: Article Writing, Blog, Blog Writing, Content Writing, Copywriting, Creative Writing, French Translator, SEO Writing Budget: $2 - $8 USD
31-Mar-2026 09:57 GMT
B2B Promo Video Editing Category: After Effects, Audio Editing, Motion Graphics, Video Post Editing, Video Production, Video Services Budget: ₹750 - ₹1250 INR
