Definitions

Hashing - Consistent Hashing

• Using a hash ring to divide hashing space into consistent servers
• Goal is to minimize the impact when adding/removing servers due to expected or unexpected reasons.
• Key => hash value => position in hash ring => move in clockwise until reaching the first avaialble server
• in case of hot spots, dynamically adding more server into that section has limited impact to other servers
• used in Memcached and Redis, Cassandra and Riak, CDN

Tree - Inorder Traversal (DFS)

• Left subtree => tree node => right subtree
• in BST => prints order

Tree - Preorder Traversal

• tree node => left subtree => right subtree
• used in copy tree?

Tree - Postorder Traversal

• left subtree => right subtree => tree node
• used in delete the tree?

Tree - Levelorder Traversal (BFS)

• level1 left to right => level2 left to right => ...