Major Description
Problem
There is no way to currently tell whether a learner gets a diff or full snapshot, or does a truncate when it connects with the leader, also how long syncing with the leader takes. There is no explicit and general indicator of how often a learner has to connect to a leader without greping through zookeeper.log
Solution
Start tracking and exporting the following three items:
- counter incremented each time a learner sync's with a leader
- the type of sync that was needed
- how long the sync took