Two-phase commit

  • Order
  • Quorum 20

Difficulty 3 of 5

Every participant votes yes. The coordinator crashes just after it saves the commit decision. Order preparation, recovery, and completion without changing that decision.

Play level

Put these steps in order

  • Participants commit, acknowledge, and release their prepared state
  • Send the commit decision to each participant
  • The coordinator restarts and reads the saved commit decision
  • The coordinator durably records commit, then crashes
  • Participants save their prepared state and vote yes
  • Ask each participant to prepare
An order and its event commit togetherTap to turn the outbox on or off

Goals and limits

p99 latency
under 200 ms
Monthly cost
under 10 USD/mo
Traffic
100 req/s

Concepts

How players did

Player results load from the server.

All levels