How is the leader chosen in a distributed system?

In distributed systems, leader election is necessary for coordinating actions among nodes and ensuring consistency. The leader election process is usually implemented using algorithms such as:

• Raft — a consensus algorithm that ensures leader election and data replication.
• Paxos — a classic consensus algorithm.
• Bully Algorithm — a simple leader election algorithm based on node priorities.

The typical working principle is as follows:

1. Nodes exchange messages about their state and priorities.
2. If the current leader is unavailable, nodes initiate the process of electing a new leader.
3. The node with the highest priority or the most up-to-date data becomes the leader.

In Go, libraries implementing Raft (such as etcd/raft) are often used, which simplify the integration of leader election into distributed applications.