[Experts opinion needed] Questions around Chronos Architecture

[agrawal...@gmail.com]

Couple of Questions around Chronos Architecture:

1. In one of the Chronos documentation I read that since crons has a SPoF crons are bad and cronos is better. How chronos avoids SPoF, how many Chronos server runs to ensure high availability? 

2. Where are job schedules saved in Chronos? Are you guys maintaining some sort of DB for that?

3. How scheduled jobs are triggered, who sends an event to Chronos to trigger the job?

4. How dependent jobs are triggered by Chronos? Are dependent jobs triggered by chronos, if yes how chronos even know when the dependee is completed? Can it distinguish failed jobs from completed ones?

5. I saw that jobs in chronos are defined using json format, any reason for using JSON and not any other format like YAML, Apache Config etc. 

6. Can a job in chronos have multiple commands? If yes will all these different commands be executed on same machine in cluster or Chronos can even launch different commands in a job in different machine?

7. If mesos already has a scheduling capability then why Chronos is even required? Can Chronos run without Mesos?

8. Does Chronos support event based scheduling? For example run my job when this file is created etc.

It will be very helpful, if someone helps me in understanding the architecture of Chronos in bit detail. Pointers to the architecture document that can clear these questions will also help.

Thanks