Configuring Activity Schedules

Setting schedules for your ClickHouse® cluster to stop, start, or rescale

The Activity Schedule settings let you control when a ClickHouse® cluster will run as well as the kinds of nodes the ClickHouse cluster will use. Altinity.Cloud does not bill you for compute resources or support for non-running clusters, so you can cut your costs by stopping ClickHouse clusters that don’t need to run constantly. (Note that these cost savings do not apply to storage and backups.) You can also cut your costs by scaling your ClickHouse clusters down to smaller, cheaper nodes during non-peak hours.

There are four items at the top of the dialog:

Activity scheduling options
  • ALWAYS ON - the cluster is always running. This is the default.
  • STOP WHEN INACTIVE - the cluster stops running after some number of hours of inactivity.
  • STOP ON SCHEDULE - the cluster runs only on certain days of the week or at certain times of the day.
  • RESCALE ON SCHEDULE - the cluster is always running, but it scales up or down to different node types on certain days of the week or at certain times of the day.

We’ll look at the four schedule options now.

ALWAYS ON

Used for mission-critical ClickHouse clusters that must run 24/7.

Figure 1 – The ALWAYS ON Activity Schedule setting

Click ALWAYS ON and click CONFIRM to save. Note that with this setting, Altinity.Cloud will not trigger any Stop or Resume operations automatically. If you stop the cluster, you’ll have to resume or restart it yourself; setting the schedule to ALWAYS ON will not automatically resume or restart it.

STOP WHEN INACTIVE

Used to stop ClickHouse clusters after a set number of hours of inactivity. For non-running clusters, Altinity.Cloud does not bill you for compute resources or support, although charges for storage and backups continue.

Figure 2 – The STOP WHEN INACTIVE Activity Schedule setting

Click STOP WhEN INACTIVE, then select the number of hours by typing in a value or by using the up and down arrows. Click CONFIRM to save. A clock icon will appear next to the cluster name in the Clusters Dashboard.

NOTE: The ACM may give you a warning message if your cluster has been inactive for a while:

Idle cluster message

Figure 3 - Unused cluster warning message

STOP ON SCHEDULE

Sets the days of the week your ClickHouse clusters will run, with the option of defining From and To times that your clusters will run for each day. (Times are expressed in GMT and are displayed in 12- or 24-hour format depending on your machine’s settings.)

The schedule for credentials below defines the following settings:

  • On Tuesday and Thursday, the cluster runs from 08:00 to 17:00 GMT, and is stopped the rest of the day.
  • On Monday, Wednesday, and Friday, the cluster runs all day.
  • On Saturday and Sunday, the cluster is stopped.

Figure 4 - The STOP ON SCHEDULE Activity Schedule setting

Click CONFIRM to save. A clock icon will appear next to the cluster name in the Clusters Dashboard.

RESCALE ON SCHEDULE

With this option your ClickHouse cluster is always running, but you can define the days of the week your cluster will run on larger, more powerful nodes, with the cluster rescaling to smaller, cheaper nodes the rest of the time. You also have the option of defining From and To times when your clusters will use the larger nodes. (Times are expressed in GMT and are displayed in 12- or 24-hour format depending on your machine’s settings.) By default the cluster runs on the larger nodes all the time.

NOTE: These settings do not start, resume, or restart the cluster, they merely define peak days or hours (Active state) when the cluster should run on larger nodes. When the cluster is in Inactive state, it’s still running, just on smaller nodes.

In the example here, the Active node type is m6i.xlarge, and the Inactive Node Type is m5.large. The Active node type is set when you create the ClickHouse cluster. To change the Inactive node type, click the down arrow icon to see the list of available node types.

The schedule for credentials below defines the following settings:

  • On Monday, the cluster starts the day in Inactive state (running on node type m5.large), scaling up to Active state (running on node type m6i.xlarge) at 08:00 GMT and continuing through the rest of the day.
  • On Tuesday, Wednesday, and Thursday, the cluster is in Active state (running on node type m6i.xlarge) all day.
  • On Friday, the cluster starts the day at midnight in Active state (running on node type m6i.xlarge), scaling down to Inactive state (running on node type m5.large) at 17:00 GMT and continuing through the rest of the day.
  • On Saturday, the cluster is in Active state (running on node type m6i.xlarge) from 09:00 GMT to 17:00 GMT, and is in Inactive state (running on node type m5.large) all other times of the day.
  • On Sunday, the cluster is in Inactive state (running on node type m5.large) all day.

Figure 5 – The RESCALE ON SCHEDULE Activity Schedule setting

NOTE: If you manually rescale the cluster, the Activity Schedule is reset to ALWAYS ON. Rescaling the cluster changes the node type it’s running on, so if you want to use the RESCALE ON SCHEDULE schedule you need to redefine the Active and Inactive node types and the times they should be used. See Rescaling a cluster for more details.

Click CONFIRM to save.