Auto scaling
Let a machine add and remove memory and vCPUs by itself, within limits you set.
With auto scaling, a machine grows its memory and vCPUs when it gets busy and shrinks them again when it is quiet. You set the lowest and highest sizes; the platform does the rest, with no approval step.
Auto scaling and its limits are set in the Add Machine form. You can't turn it on, turn it off or change the limits on an existing machine. Choose your limits carefully, or create a new machine if you need different ones.
Turn on auto scaling
- Start creating a machine as usual: see Create a machine.
- Tick Enable Auto Scaling. Four limit fields appear.
- Fill in the limits you want (details below). Leave a field empty to use its default.
- Finish the form and click Add.
If you untick Enable Auto Scaling, the limit fields are hidden and cleared.
The limits
| Field | What to enter | If you leave it empty |
|---|---|---|
| Min vCPUs | The fewest vCPUs the machine may shrink to. | The vCPUs of the image you picked. |
| Max vCPUs | The most vCPUs the machine may grow to. | The maximum your Tier allows. |
| Min Memory (MB) | The least memory, in MB, it may shrink to. For example 2048 for 2 GB. | The memory of the image you picked. |
| Max Memory (MB) | The most memory, in MB, it may grow to. For example 16384 for 16 GB. | The maximum your Tier allows. |
Enter whole numbers; 0 counts as empty. The platform checks the limits when you click Add: if they aren't accepted, you'll see an error, the machine isn't created and the form closes.
Leaving the maximums empty lets the machine grow to your tier's limit, and its cost can grow with it. Set Max vCPUs and Max Memory (MB) to the largest size you're willing to pay for. See Live costs.
What happens next
- The machine is resized automatically based on its live CPU and memory use. Steps the operating system supports live happen without downtime.
- On the Machines screen in Cards view, the card footer shows Auto-scaling A to B vCPU, and the card briefly lights up when its size changes. Machines without auto scaling show Manual size.
- In the machine's General tab, Auto Scaling shows Enabled with the vCPU and memory ranges, or Disabled.
- To watch it work, open the Live Stats tab: see Monitor a machine.
Machines without auto scaling
A machine created without auto scaling keeps the size you give it. You can still change its memory and vCPUs by hand at any time: see Resize a machine.