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.
Premium E-Bike Online Store Category: ECommerce, HTML, PHP, SEO, Shopify, UI / User Interface, UX / User Experience, Web Design, WooCommerce Budget: $250 - $750 AUD
05-Jan-2026 11:04 GMT
WordPress Festival Travel MVP Category: API Integration, Email Marketing, Full Stack Development, Google Analytics, HTML, PHP, Web Development, Web Design, WordPress Budget: $250 - $750 USD
05-Jan-2026 11:03 GMT
Optimize Blogger Post for SEO Category: Content Writing, Copywriting, Digital Marketing, Internet Marketing, Keyword Research, Link Building, SEO, Website Optimization Budget: ₹600 - ₹1500 INR
figma design for Lead-Optimized Website Redesign Category: Figma, Graphic Design, HTML, Lead Generation, UI / User Interface, User Interface / IA, UX / User Experience, Web Design, Website Optimization Budget: ₹1500 - ₹12500 INR
05-Jan-2026 11:01 GMT
Futuristic Superhero Comic Creation Category: Character Illustration, Comics, Concept Art, Concept Design, Creative Design, Digital Art, Graphic Design, Illustration, Visual Arts Budget: ₹600 - ₹4000 INR
05-Jan-2026 11:00 GMT
Logo dengan Simbol Ikonik Category: Adobe Illustrator, CorelDRAW, Graphic Design, Icon Design, Illustration Budget: $15 - $25 USD
05-Jan-2026 11:00 GMT
Health & Medical Research Report Category: Academic Writing, Content Writing, Data Analysis, Health Care Management, Medical, Medical Devices Sales, Medical Writing, Research, Research Writing, Technical Writing Budget: ₹400 - ₹750 INR
05-Jan-2026 10:59 GMT
Cinema 4D Educational Video Category: 3D Animation, 3D Design, 3D Modelling, After Effects, Animation, Cinema 4D, Storyboard, Video Editing Budget: €8 - €30 EUR
Call Casinos For Table Details Category: Customer Service, Data Collection, Data Entry, Excel, Korean Translator, Market Research, Vietnamese Translator, Web Scraping, Web Search Budget: €8 - €30 EUR
05-Jan-2026 10:58 GMT
Mavibot Client-Qualifying Chatbot Setup Category: AI Chatbot Development, API Integration, Chatbot, Chatbot Integration, Conversational AI Budget: $30 - $250 USD