Leader Election Protocal

Controller Election in Quorum

• Controller Role:

  • Every controller in the quorum is a voter

• Failure and Election Process:

  • When the active controller fails:
    • One of the voters attempts to become a candidate for the new leader
    • The candidate requests votes from each voter

• Election Outcome:

  • If the candidate receives a majority of votes (including its own):
    • The candidate becomes the new leader
  • If no majority is received within a specific timeout:
    • The election process is considered a failure
    • Another voter attempts to become a candidate, and the process repeats

• Voting Mechanism:

  • The actual voting process is based on Kafka’s voting mechanism, utilizing the concept of epochs

Why Kraft

Replication via Quorum Replication of Raft Protocol but pull-based like Kafka protocol. New protocol for leader election but leverages Kafka’s epoch method for voting. A mix of Raft & Kafka protocols - Kraft