Multi Site Chef Server Availability - chef-boneyard/chef-summit-2014 GitHub Wiki

Location

Thursday, Medina, 10:30

Convener

Participants

Summary of Discussions

How do you do HA/DR?

Individual "disconnected" servers that are replicated via other means

  • Put all config policy into version control and use a synchronization process to push that data to your individual sites. (Basically, use automated release practices and version control for your big-scale production Chef changes)
    • Note that this is scoped to one organization...
  • Write client handler that ships relevant node data to another Chef server (or replication service?).
  • Requires people to be explicit about the way they load data about their environments - because you lose indexing across servers, you can't run Chef search in data center 1 and get timely responses about nodes from data center 2.

How do you do global availability?

How do you find the right Chef server?

  • Wide IP / central redirect service? (May require client modification to follow 302s)
  • DNS search suffix? Directional/Anycast DNS?

Resynchronization after forced partitioning (e.g. link failure)

  • A big, messy problem. This is why Chef recommends one-server-per-data-center and using object-based replication.
  • Search remains a different problem domain from keeping Chef objects in sync.
    • Add optional scope to Chef searches?
  • How do you replicate user public keys from one Chef server to another?
    • If only OC-ID held this data instead - that'd be a much easier service to replicate...

What will we do now? What needs to happen next?

  • Most of the people in the room haven't played with chef-sync (Chef 12 enterprise add-on) yet. (Doesn't solve the federated search issue, though)
  • ChefCorp could be a little more prescriptive (white papers? Or provide some models - cookbook(s)? chef-metal script that does this for us? ) with regards to Chef server deployments that satisfy some or all of these scenarios.

Epilogue

  • It is also concluded and resolved that Peter Capaldi is doing a great job as the Doctor.