Schedule

The recommendation schedule defines how often recommendations are generated and how long they’re valid for

Optimize Live generates a new recommendation for a workload on the schedule that you define.

Schedule

The schedule on which Optimize Live generates new recommendations for a workload.

Annotation	Default value
`live.stormforge.io/schedule`	`"@daily"`

Description

Recommendations are generated automatically for workloads on a schedule, defined by a schedule string.

The schedule also affects every recommendation’s TTL, or time-to-live. The TTL is how long the recommended values are considered valid for. After a recommendation’s TTL expires, the recommended values are replaced by new values from an updated recommendation.

The shortest valid recommendation schedule is once an hour.

Duration expressions

Valid ISO 8601 Duration strings can be specified as schedules.

Examples

PT1H – Once an hour
P1D – Once a day
P7D – Once a week

Cron expressions

Cron strings can be used to designate schedules with more specific requirements, such as day-of-week. Cron expressions should specify five fields. For day-of-week, friendly terms such as WED or THU are acceptable in place of numbers. Optimize Live recognizes the special value H in a field to mean “hash” this value, and use a deterministic, but functionally random value for that field.

Cron times must always be specified in UTC.

Examples

H H * * THU – Once every Thursday
0 30 * * SAT,MON – 12:30am each Saturday and each Monday UTC
H H(0-2) * * * – Every day between 12:00am and 2:59am UTC

Schedule macros

Macros are shorthand that can be used as syntactic sugar for common schedules. The available macros are described below and compared with their duration and cron equivalents.

Macro	Duration	Cron	Description
`@never`	`P0D`	N/A	Do not generate recommendations at all.
`@hourly`	`PT1H`	`H * * * *`	Once every hour.
`@daily`	`P1D`	`H H * * *`	Once every day.
`@weekly`	`P7D`	`H H * * H`	Once every week.
`@midnight`	N/A	`H H(0-2) * * *`	Every day between 12:00am and 2:59am UTC

Key points

Each workload can have one and only one schedule string defined for it, of either a duration, cron expression, or schedule macro.
Exact times are not guaranteed for recommendation generation. For exact cron strings, recommendations are generated within an hour of the time specified.
To avoid concentrated pod churn when new recommendations are applied, use schedules that spread optimization over a period of time. The H capability in cron expressions or using non-specific durations can both help achieve an appropriate scheduling distribution.

Last modified June 6, 2024