Autoscale Virtual Server

VS autoscaling allows you to change the RAM, CPU and disk size settings of a virtual server automatically. VS resources scaling is based on rules you specify. For example, you can set up a rule that will add 1000MB of memory to a VS if RAM usage has been above 90% for the last 10 minutes - but add no more than 5000MB in total in 24 hours. You can set autoscaling down settings alongside with autoscaling up.

  • For Linux-based VSs and VS primary disks only.
  • Disk usage autoscaling is applicable for VS primary disk only.
  • Autoscaling for CPU cores is currently not implemented, it is implemented only for CPU units and CPU shares. 
  • If the VS is based on a template that allows resizing without reboot - see the Edit Virtual Server section – then the VSs RAM or CPU or both can be increased without rebooting the VS. The resources that can be resized without reboot depend on the template and the virtualization type. Some templates support the resize without reboot only for either CPU or RAM. Disk space autoscaling requires a VS reboot.
  • If you autoscale a VS's memory to a value greater than current VS RAM x 16 (which is a max_memory parameter in a configuration file and database), the VS will be rebooted anyway, regardless of the template it is built on.
  • Make sure a VS can be reached via SSH. Otherwise, the autoscaling client installation will fail.
  • Starting with version 4.2, OnApp uses Zabbix for autoscaling. Monitis will be used for autoscaling of servers built using OnApp versions previous to 4.2 until you switch autoscaling off for such server(s). If you decide to switch autoscaling back on, autoscaling will be implemented using Zabbix. Zabbix also will be used for autoscaling of newly created VSs.
  • When autoscaling down is enabled, it will reduce the VS memory and disk size to the the minimum, indicated in template, on which this VS is built. CPU usage can be reduced to the minimum CPU priority allowed by the system(1%).

To configure autoscaling setitngs:

  1. Go to your Control Panel's Virtual Servers menu.
  2. Click the label of the appropriate VS.
  3. On the page that follows, click the Overview tab, and then click Autoscaling.
  4. Press the required tab - Memory Usage, Disk Usage or CPU Usage - to see the statistics for each type of resources.
  5. Below you will see UP and DOWN autoscaling options. Move the slider to the right to add the autoscaling rule or move it to the left to remove the rule.
  6. Add autoscaling rules as explained below:

    Set autoscale up options:

    • If RAM usage is above X% for a specific time period, add Y MB – but no more than Z MB in a 24 hour period.
    • If CPU usage is above X % for a specific time period, add Y% - but no more than Z% in a 24 hour period.
    • If disk usage is above X % for a specific time period, add Y GB - but no more than Z GB in a 24 hour period.

    Set autoscale down options:

    • If RAM usage is below X% for a specific time period, remove Y MB.
    • If CPU usage is below X % for a specific time period, remove Y%.
    • If disk usage is below X % for a specific time period, remove Y GB.
  7. Click Apply.

Clicking the Apply button does not activate autoscaling if the Autoscale slider at VS overview page is disabled. You can configure autoscaling rules, press the Apply button, these rules will be saved and will start working only after the Autoscale slider at VS overview page is enabled. Also you can disable the Autoscale slider, autoscaling will stop working, but the configuration of rules will be saved in case you will want to activate them in future.