Things that I stumbled on a rainy day.

• Understanding how Trie (Data Structure) works
• Understanding how Raft (Distributed Consensus algorithm) works

Trie

I have heard/seen it but not in detail until now. Saw someone posted about it on HN and makes me curious.

I also found a post about Trie written in Python by Googling. I like the clear explanation with diagrams and put the code on github.

Some takeaways

• Cool data structure to build autocomplete / prefix tree.
• Two main functions
  • Insert
  • Query

Raft

Another item on my endless “things to read” list is this particular Understanding Distributed Consensus link.

Some takeaways

There are two main processes

1. Leader Election
   • How all the nodes in the system came to an agreement on who should be the leader among them
   • States of the Nodes
     • Follower
     • Candidate
     • Leader
2. Log Replication
   • Once the leader is elected, all the changes go through the leader.
   • The leader then replicates the change to all the followers.
   • The leader waits until a majority of them have written the entry.
   • Then the leader commits the state and confirms that to the followers.

There are a lot more details than this so probably will go back to the link above from time to time. And maybe I will have to try implementing it.