Page Comparison

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To split the Worker application to a separate host from the rest of Avalon, essentially, you want to set up two identically-configured Avalon deployments -- but some services are not installed, or are disabled, on each.

Avalon Host should run

• Avalon application
• Redis
• Avalon DB (needs to be accessible from the Worker host)
• SOLR/Fedora (although these may be on separate hosts if desired)

The Avalon host should *not* be running this service (it needs to be explicitly disabled)

•  Sidekiq

Worker Host should run

• Sidekiq
• Redis

Worker host should have these disabled or simply not installed:

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There are mixed reports about the best place to run Redis. It can be run on either the Web host or the Worker.

Connecting the two instances

• The Avalon Web and Worker hosts have basically identical configurations, just with different services enabled.
• At the very least, they need to point to the same Avalon DB (which must be reachable from both hosts)

  • Configured in config/database.yml

• You *might* need to have identical Fedora configs on both hosts. It's unclear whether this is required on the Worker.

  •  Configured in config/fedora.yml

Web Host

• Install full Avalon rails app
• Configure app to connect to database, solr, fedora
• In `settings.yml`
  • comment-out ffmpeg section
• Change redis section to connect to redis on worker node

Enable:

• Avalon application
• SOLR/Fedora (although these may be on separate hosts if desired)
• Redis (unless running it on the Worker)

Configure:

• Database (open to Worker host)
• Redis (if running on Worker)

Stop and disable:

•  Sidekiq

Worker Host

•  Install full Avalon rails app (or just clone the Web node)
• Configure app to connect to same database as the web node in `config/database.yml`
• Comment-out all content in:
  • blacklight.yml
  • solr.yml
  • fedora.yml

Worker Host should run:

• Sidekiq
• Redis (unless running it on the Web host)

Stop and disable:

• Avalon rails app
• Avalon DB (the Worker should not be running its own db, but it does need to be able to reach the Avalon DB)
• SOLR
• Fedora

Mount NFS shares

• should be mounted at the same paths as Web node):
  • dropbox
  • derivatives
  • masterfiles
  • supplementalfiles