Adding servers before a known peak

A schedule holds a node group at a floor, under a ceiling, or both, at the same time every week, so the servers for a peak you know about are running before it starts. Autoscaling keeps working inside the window, and the end of a window removes nothing.

What is a schedule, and how does it combine with the policy?

A schedule on the group’s Schedules page has a name, the days it applies, a start (“From”), an end (“Until”) and a capacity: “At least”, “At most” or both, counted in servers with the seed included. An end at or before the start ends on the next day.

When one of its windows starts:

• At least above the group’s current count raises it: Hetscale adds the servers that are missing, held by the same checks as any other new server, such as the cost guard and the euro ceiling.
• At most below the current count lowers it: Hetscale releases the surplus the way a change you make by hand does, servers not yet created first, then servers on their way, then the newest serving servers through the drain window.

While the window runs, the policy decides inside its bounds: it can add servers above the floor and remove them again down to it, and it adds none above the ceiling. A floor never goes above the group’s maximum, and a ceiling never below its minimum. When windows cross and the highest floor is above the lowest ceiling, the floor wins: capacity is the safer mistake.

The end of a window removes nothing. The servers it added stay until the policy’s scale-in rules release them, one at a time.

Adding a schedule plans its windows for the next seven days, and the Schedules page names the next one, or the one running now (“Now: …”). A change removes the windows that have not started and plans the week again; switching a schedule off removes them, and a window that is running ends as planned. “Hold capacity now” keeps at least the number of servers you choose from now on, for 1, 2, 4, 8, 12 or 24 hours; autoscaling can still add more.

Delete removes a schedule after a confirmation. Its windows that have not started go with it, a window that is running ends as planned, and the windows that ran are kept as history. To keep a schedule for later, switch it off instead.

Windows apply to a Live group. In Propose mode they act without waiting for your approval, like healing, and a paused group applies them when it runs again.

Which time zone does it use?

Your organisation’s time zone, which its owner sets on the organisation’s profile. Schedules are the organisation’s rules, so they are entered and shown in that zone, and the Schedules page says which: “Times are in Europe/Berlin.” A daylight-saving change does not move a window; each one keeps its local start and end.

Every other time in the panel, the group’s timeline and the alert mails included, is shown in each member’s own display time zone, which a member picks on their profile.

Which plans include it?

Pro and Team, “Hold capacity now” included. On another plan the Schedules page says so and changes nothing: your rules are kept, and they apply again once the plan includes scheduled scaling.

What does this not cover?

• Suggestions for a schedule, drawn from weekday ramps in your history where autoscaling arrived late, are planned, and so is letting Hetscale manage such a schedule for you.
• A scheduled server is created like any other, through the stock fallback chain: When your Hetzner server type is sold out.
• When the policy adds and removes servers on its own: When Hetscale adds or removes a server.
• How long a new server takes to take traffic: How fast is a scale-out.