example-7.md

Example 7: 3 node cluster, 1 peer dies while joining

• Nodes A, B, and C fully in the cluster

• Local state before (1): {:pairs {:a :b, :b :c, :c :a}}

• D wants to join

• D sends prepare-join-cluster (1)

• A, B, C, and D play the log

• D encounters (1)

  • Pre: {:pairs {:a :b, :b :c, :c :a}}
  • Post: {:pairs {:a :b, :b :c, :c :a} :prepared {:d :a}}
  • determines D will attach to A. Records this in the local state.
  • adds watch to A
  • sends notify-join-cluster (2)
  • D dies. No peer is watching, so this isn't reported

• A, B, C encounter (1)

  • Pre: {:pairs {:a :b, :b :c, :c :a}}
  • Post: {:pairs {:a :b, :b :c, :c :a} :prepared {:d :a}}
  • ignore

• A, B encounter (2):

  • Pre: {:pairs {:a :b, :b :c, :c :a} :prepared {:d :a}}
  • Post: {:pairs {:a :b, :b :c, :c :a} :accepted {:d :a}
  • ignore

• C encounters (2):

  • Pre: {:pairs {:a :b, :b :c, :c :a} :prepared {:d :a}}
  • Post: {:pairs {:a :b, :b :c, :c :a} :accepted {:d :a}
  • tries to add a watch to D, notices its dead
  • sends abort-join-cluster (3)

A, B, C encounter (3):

• Pre: {:pairs {:a :b, :b :c, :c :a} :accepted {:d :a}
• Post: {:pairs {:a :b, :b :c, :c :a}
• rollback accepted peer