Some examples of running in a background job environment? about webshot HOT 1 OPEN

It's not recommended to start multiple PhantomJS concurrently. You should serialize the access, treat it as unreliable and monitor it with daemontools, god, monit, etc. My current setup:

   S3 <-- CloudFront + 404 handler <-- User Request
    ^
    |
Worker <--> Screenshot Service API (Heroku)
    |
    ^
    |
Queue < -- App

Screenshots are cached on S3 and served through CloudFront CDN. Heroku restarts the service automatically when it crashes and CloudFront serves a default image with a low TTL if the screenshot is not yet ready. Take a look at this gems too:

unicorn-worker-killer
unicorn-soft-timeout

from webshot.