Rails renders every page on the server.
There is no CDN cache to absorb an SSL certificate expiry.
Rails agencies deploy client applications to Render, Fly.io, Heroku, and DigitalOcean App Platform. Every page request hits a live server — there is no static HTML layer to continue serving while SSL is repaired. When a Rails server SSL certificate expires, every page request and every API call fails immediately, with no warning beyond the browser SSL error your client sees. Merlonix monitors SSL and DNS so you know 30 days before expiry.
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- Check cadence (Agency)
- 5 min
- SSL pre-expiry alert
- 30 days
- Independent DNS resolvers
- 3
- Vendors watched
- 11
Where Rails agencies get caught out
Three failure modes specific to Rails client deployments on Render, Fly.io, and Heroku.
Rails agencies managing server-side client deployments deal with immediate total-outage SSL expiry, Heroku migration CNAME residue, and API-only backend SSL that expires independently from the frontend and is often discovered only after silent failures.
Rails server SSL expiry is an immediate total outage — no cached pages, no partial failure
A Rails application SSL expiry fails every page request and every API call at the same moment — there is no CDN cache layer to continue serving content while the certificate issue is resolved
Rails generates every page on the server at request time. Unlike static-generated frameworks where pre-built HTML continues serving from a CDN even after a backend failure, a Rails application has no cached page layer to absorb an SSL outage. When the SSL certificate on a Render web service, Fly.io application, or Heroku dyno expires, every incoming request — page loads, form submissions, API calls from mobile apps, webhook deliveries from third-party services — fails with an SSL handshake error simultaneously. There is no grace period, no partial degradation, no cached content that continues to serve while the certificate is renewed. For client Rails applications that handle authentication, transactions, or real-time data, the outage is immediately visible across every user and every integration the moment the certificate expires.
Heroku-to-Render and Heroku-to-Fly migrations leave dangling CNAME records
Migrating a Rails application from Heroku to Render or Fly.io changes the CNAME target but the old Heroku custom domain configuration keeps the previous CNAME active in client DNS
Rails agencies migrating client applications away from Heroku — to Render for cost reasons, to Fly.io for latency improvements, or to DigitalOcean App Platform for simplicity — update the client's DNS CNAME to point at the new platform's hostname. Heroku's custom domain configuration for the original application remains active until the agency explicitly removes it from the Heroku app settings. The old Heroku CNAME entry in the client's DNS zone continues to resolve — pointing at Heroku's infrastructure — for as long as it takes the agency to identify and remove the stale record. After the Heroku application is eventually decommissioned or the Heroku account is closed, the old CNAME becomes a dangling record pointing nowhere. Depending on how the client's DNS provider handles the TTL, the dangling record can cause intermittent resolution failures that are difficult to diagnose without visibility into CNAME target integrity.
Rails API-only backends have SSL independent from the frontend domain
Rails API-only applications serving SPA or mobile frontend clients run on a separate subdomain with independent SSL — both certificates expire on different schedules and are often managed by different people
Rails agencies building full-stack applications often deploy a Rails API-only backend on api.clientdomain.com and a separate React, Vue, or mobile frontend consuming it. The API subdomain SSL certificate is provisioned separately from the main domain — on a different Render service, Fly.io application, or Heroku app — and expires on a different date. Agencies that monitor only the primary domain miss the API subdomain expiry until the mobile app or SPA begins returning authentication errors, payment processing failures, or empty data responses. When the Rails API SSL expires, the mobile app may not display a user-visible error immediately — it may silently fail to load data, or show a cached state that appears functional to the client but is not making live API calls. The expiry is discovered during a client review or when a user reports that the app "stopped working" — not from a browser SSL warning.
How it works
SSL and DNS monitoring for Rails applications on Render, Fly.io, Heroku, and DigitalOcean.
Merlonix monitors CNAME integrity and SSL health for Rails applications and API backends — with 30-day expiry warnings before a server SSL failure becomes an immediate total client outage.
01
Add the application domain, API subdomains, and legacy platform CNAMEs
Verify ownership with a DNS TXT record on the apex domain. API-only backend subdomains, staging environments, ActionCable WebSocket subdomains, and legacy Heroku or DigitalOcean CNAMEs from prior migrations are added without additional verification. Monitoring legacy records catches platform decommission problems before dangling CNAMEs surface as intermittent failures. Under two minutes per client.
02
CNAME integrity checks on Render, Fly.io, and Heroku hostnames
Three independent DNS resolvers check every CNAME delegation on every monitoring interval — whether the target is a Render web service hostname, a Fly.io application hostname, a Heroku dyno hostname, or a DigitalOcean App Platform URL. When a Heroku migration leaves a conflicting old CNAME, the target mismatch is detected immediately. When a Fly.io application is redeployed to a new hostname and the custom domain loses its routing, the break is detected before clients report it.
03
SSL monitoring 30 days before the immediate-outage expiry
Full SSL chain validation on every Rails application domain and API subdomain. An expiry alert fires 30 days before the certificate expires — enough lead time to renew before a Rails server SSL failure causes a complete application outage. Render, Fly.io, Heroku, and DigitalOcean each manage certificate provisioning independently; Merlonix monitors every certificate regardless of which platform provisions it.
04
Vendor status for Render, Fly.io, Heroku, and DigitalOcean
Merlonix monitors Render, Fly.io, Heroku, and DigitalOcean platform status alongside client SSL and DNS. When a Render infrastructure incident causes Rails application SSL failures across multiple client deployments simultaneously, you see the vendor event — not a cascade of individual client alerts that each require separate investigation.
What the numbers mean for Rails agencies
Monitoring built for Rails agencies where SSL expiry means immediate total outage with no buffer.
Rails agencies managing server-side client deployments need SSL monitoring with enough lead time to act before expiry — because a Rails server SSL failure is immediate and total, affecting every page request and API call without a CDN layer to absorb the impact.
< 10 min
Time from DNS change to alert — catches Heroku migration CNAME residue and Fly.io custom domain routing breaks before clients notice
30 days
SSL expiry warning lead time — enough time to renew before a Rails server SSL expiry causes an immediate total application outage with no CDN buffer
11 vendors
Upstream services monitored — Render, Fly.io, and Heroku included to distinguish platform incidents from client DNS changes on Rails deployments
200 assets
Maximum monitored domains on the Agency plan — covers production, API subdomains, staging, and legacy platform CNAMEs across a full Rails client roster
Pricing
Flat monthly fee. Every server deployment and API subdomain included.
No per-domain charges. No per-platform fees. Pick the tier that fits your Rails client count and monitor every server deployment without billing surprises.
Starter
For individual Rails developers managing a small server-side client portfolio.
$29/ month
- 10 monitored assets
- 1 seat
- 15-min check cadence
- SSL + DNS + vendor monitoring
- Email + Slack alerts
Team
For Rails agencies managing client deployments across Render, Fly.io, and Heroku.
$79/ month
- 50 monitored assets
- 5 seats
- 10-min check cadence
- SSL + DNS + vendor monitoring
- Email + Slack alerts
Agency
For agencies with a full Rails client roster across multiple server-based hosting platforms.
$199/ month
- 200 monitored assets
- 15 seats
- 5-min check cadence
- SSL + DNS + vendor monitoring
- Email + Slack alerts
Know when a Rails server certificate is about to expire — before the immediate total outage.
Add your first Rails client domain in under two minutes. Server applications on Render, Fly.io, Heroku, and DigitalOcean are monitored from the same dashboard, alongside API subdomains and legacy platform CNAMEs. 14-day trial, no card required.