Chronos as a cluster scheduler
One can consider Chronos as a time-based job scheduler, such as cron in the typical Unix environment. Chronos is distributed and fully fault-tolerant, and it runs on top of Apache Mesos.
Just like cron, Chronos executes the shell scripts (combined with Linux commands) by default and also supports Mesos executors.
Chronos can interact with systems such as Hadoop or Kafka even if the Mesos worker machine, on which the real execution happens, does not have the system installed. You can use Chronos to start a service or run a script on a remote machine in the background. The wrapper script can have an asynchronous callback to alert Chronos to the job status, such as whether it is completed or failed and so on. For the most part, people use Chronos to run dockerized applications. A detailed explanation of dockerized applications is provided in Chapter 7, Mesos Containerizers.
Chronos comes with a Web UI in which you can see the job status, statistics of the job's history...