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.
Meta Ads Lead Generation Category: A / B Testing, Advertising, Content Creation, Conversion Rate Optimization, Digital Marketing, Facebook Marketing, Instagram Marketing, Lead Generation, Social Media Marketing, Video Editing Budget: ₹1500 - ₹12500 INR
23-Feb-2026 11:01 GMT
Vibrant Imagination Book for Toddlers Category: Book Design, Book Writing, Content Writing, Creative Writing, Editing, Fiction, Ghostwriting, Proofreading, Publishing, Writing Tutoring Budget: €30 - €250 EUR
23-Feb-2026 11:01 GMT
Multiplayer Gaming Platform Development Category: Android, Backend Development, Flutter, Game Design, Game Development, Game UI, IOS Development, Mobile App Development, Online Multiplayer Budget: $750 - $1500 USD
23-Feb-2026 11:01 GMT
Lyric Video With Motion Graphics Category: 2D Animation, 3D Animation, Adobe Premiere Pro, After Effects, Animation, Graphic Design, Motion Graphics, Video Editing, Video Production, Video Services Budget: ₹600 - ₹1500 INR
23-Feb-2026 11:01 GMT
Podcast Social Media Manager Category: After Effects, Animation, Content Creation, Content Strategy, Instagram Marketing, Social Media Management, Social Media Marketing, Video Editing, Video Services Budget: €12 - €18 EUR
Facebook Lead Generation Campaign Category: Digital Marketing, Facebook Ads, Facebook Marketing, Google Adwords, Google Analytics, Internet Marketing, Lead Generation, Social Media Marketing Budget: ₹12500 - ₹37500 INR
Craft Arab Justice Advocacy Messaging Category: Content Writing, Copywriting, Public Relations, Research Writing, Social Media Marketing, Translation, Writing Tutoring Budget: $25 - $50 USD
23-Feb-2026 10:58 GMT
GPT Optimization Expert Category: AI (Artificial Intelligence) HW / SW, AI Chatbot Development, AI Model Development, Internet Marketing, PHP, Prompt Engineering, SEO Budget: ₹1500 - ₹12500 INR
23-Feb-2026 10:57 GMT
Excel Data Entry and Statistical Analysis Category: Data Analysis, Data Entry, Data Processing, Data Visualization, Excel, Python, Statistical Analysis, Statistics Budget: $2 - $8 USD
