Khronos - Fault tolerant job scheduling system

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CRON

Field name	Mandatory?	Allowed values	Allowed special characters
Seconds	Yes	0-59	* / , -
Minutes	Yes	0-59	* / , -
Hours	Yes	0-23	* / , -
Day of month	Yes	1-31	* / , - ?
Month	Yes	1-12 or JAN-DEC	* / , -
Day of week	Yes	0-6 or SUN-SAT	* / , - ?

Predefined schedules

Entry	Description	Equivalent To
@yearly (or @annually)	Run once a year, midnight, Jan. 1st	0 0 0 1 1 *
@monthly	Run once a month, midnight, first of month	0 0 0 1 * *
@weekly	Run once a week, midnight between Sat/Sun	0 0 0 * * 0
@daily (or @midnight)	Run once a day, midnight	0 0 0 * * *
@hourly	Run once an hour, beginning of hour	0 0 * * * *

Intervals

You may also schedule a job to execute at fixed intervals. This is supported by formatting the cron spec like this:

@every <duration> 

For example, “@every 5s” would indicate a schedule that activates 5 seconds.

Concurrency

allow (default): Allow concurrent job executions. forbid: If the job is already running don’t send the execution, it will skip the executions until the next schedule.

Fault tolerance

Fault detection, Failover, Failtry.

Load banlancing

support Random, Workload RoundRobin

Requirements

Khronos relies on the key-value data storage, Currently only etcd is supported

Getting Started

Supposed you have installed Khronos onto your machine, you can follow the below steps to start using it.

To Run khronos:

$ khronos agent -e local

TODO

• Support Distributed
• REST API