New Definitions

Question 1

2 phase comit

Answer 1

doesn’t scale well
need to wait for all resources to answer
a lot of messages pass through coordinator

Question 2

cap pyramid

Answer 2

pick 2 :

Consistency: Every read receives the most recent write or an error
Availability: Every request receives a (non-error) response, without the guarantee that it contains the most recent write
Partition tolerance: The system continues to operate despite an arbitrary number of messages being dropped (or delayed) by the network between nodes