The Bully Election Algorithm

by Garcia-Molina (1982)

Recall the assumption that each process has a unique number.

The algorithm:

• One process notices that the leader/server is missing and
  • Sends messages to all other processes;
  • Requests to be appointed leader;
  • Includes his processor number.
• Processes with higher (lower) process numbers can bully the first process.
• The process with highest id wins the election and sends out a message to that effect.

The process that initiates the election need only send messages about election to higher numbered processes.

Any processes that respond effectively tell the first process that they overrule him and that he is out of the running as they have higher ids.

These processes then start sending election messages to the other high-numbers processes.

See example on next page.

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Comments:
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