backup_cron.md

Contents(Deprecated)

• Overview
• Configuration of scheduled backups
  • Cron expression format
    • Special characters
    • Predefined schedules
• both cron backup for s3 and nfs

Overview

The scheduled backup is currently supported for both S3 and NFS backups. You can use the cron expression to specify the backup schedule. Set the backupSchedule parameter under the spec field in the YAML file of the cluster, for example:

... 
spec:
  replicas: 3
  backupSchedule: "0 0 0 * * *"  # daily
  ...

Configuration of scheduled backups

Cron expression format

A cron expression represents a set of times, using 6 space-separated fields in the format of [second] [minute] [hour] [day] [month] [day of week].

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	* / , - ?

Note: Month and Day-of-week field values are case-insensitive. SUN, Sun, and sun are equally accepted.

Special characters

Asterisk ( * )

The asterisk indicates that the cron expression will match for all values of the field. For example, using an asterisk in the 5th field (month) would indicate every month.

Slash ( / )

Slashes are used to describe increments of ranges. For example 3-59/15 in the 1st field (minutes) would indicate the 3rd minute of the hour and every 15 minutes thereafter. The form *\/... is equivalent to the form first-last/..., that is, an increment over the largest possible range of the field. The form N/... is accepted as meaning N-MAX/..., that is, starting at N, use the increment until the end of that specific range. It does not wrap around.

Comma ( , )

Commas are used to separate items of a list. For example, using MON,WED,FRI in the 5th field (day of week) would mean Mondays, Wednesdays and Fridays.

Hyphen ( - )

Hyphens are used to define ranges. For example, 9-17 would indicate every hour between 9am and 5pm inclusive.

Question mark ( ? )

Question mark may be used instead of * for leaving either day-of-month or day-of-week blank.

Predefined schedules

You may use one of several pre-defined schedules in place of a cron expression.

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 on Sunday	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 * * * *

both cron backup for s3 and nfs

if you have specified the backupSecretName , nfsServerAddress and backupSchedule , the operator will run nfs backup instead of s3 backup, but if you want backup them both, you should specify bothS3NFS field. it has two sub fields.

• nfsSchedule: nfs' Cron expression, reference from Predefined schedules
• s3Schedule: s3's Cron expression, reference from Predefined schedules for examples:

... 
spec:
  replicas: 3
  mysqlVersion: "5.7"
  bothS3NFS: 
    nfsSchedule: "0 0 0 * * *"
    s3Schedule:  "0 0 2 * * *"
  ...