Scaling disk, memory, and CPU

Scaling in the UI

For new hosting models, resource scaling is currently available through the CLI and API.

A visual representation of your data members and their resource allocation is available on the Resources page of your deployment on the IBM Cloud console.

Adjust the slider to increase or decrease the resources that are allocated to your service. The UI currently uses a coarser-grained resolution than is available via the CLI or API. The UI shows the total allocated memory or disk for the position of the slider. Click Scale to trigger the scaling operations and return to the dashboard overview.

Review current resources and hosting model

IBM Cloud CLI cloud databases plug-in supports viewing and scaling the resources on your deployment. Use the command cdb deployment-groups to see current resource information for your service, including which resource groups are adjustable. To scale any of the available resource groups, use cdb deployment-groups-set command.

For example, with the following command you can view the resource groups for a deployment named "example-deployment". Note that this command will also reveal if your database is a Shared Compute or Isolated Compute instance through the hostflavor attribute. If the hostflavor is null, it is on an old style hosting model.

ibmcloud cdb deployment-groups <INSTANCE_NAME_OR_CRN>

This command produces the output:

Group   member
Count   3
|
+   Memory
|   Allocation              6144mb
|   Allocation per member   2048mb
|   Minimum                 6144mb
|   Step Size               256mb
|   Adjustable              true
|
+   CPU
|   Allocation              0
|   Allocation per member   0
|   Minimum                 6
|   Step Size               2
|   Adjustable              true
|
+   Disk
|   Allocation              30720mb
|   Allocation per member   10240mb
|   Minimum                 30720mb
|   Step Size               2048mb
|   Adjustable              true

The deployment has three members, with 6144 MB of RAM and 30720 MB of disk allocated in total. The "per member" allocation is 2048 MB of RAM and 10240 MB of disk. The minimum value is the lowest the total allocation that can be set. The step size is the smallest amount by which the total allocation can be adjusted.

Resources and scaling in the CLI

The cdb deployment-groups-set command allows either the total RAM or total disk allocation to be set in MB. For example, to scale the memory of the "example-deployment" to 4096 MB of RAM for each memory member (for a total memory of 12288 MB), you use the command:

ibmcloud cdb deployment-groups-set <INSTANCE_NAME_OR_CRN> member --memory 12288

Determine the hosting model of your database

Use the following command to review the value of the hostflavor attribute. This will be null if the database is on a deprecated hosting model (not Shared or Isolated Compute).

ibmcloud cdb groups <deployment_id> --json

Switching to and between Hosting Models in the CLI

If your database is a Shared Compute instance, you can adjust the memory, CPU, and disk options with the following command. If your database is not on Shared Compute, this command will also move a database from a different hosting model to the Shared Compute hosting model.

ibmcloud cdb deployment-groups-set <deploymentid> <groupid> [--memory <val>] [--cpu <val>] [--disk <val>] [--hostflavor multitenant]

For example, use the following to scale to a Shared Compute instance or scale up your Shared Compute instance:

ibmcloud cdb deployment-groups-set crn:abc ... xyz:: member  --memory 24576 --cpu 6  --hostflavor multitenant

If your database is an Isolated Compute instance, memory and CPU are adjusted together by selecting the Isolated Compute size (see all sizes in Table 1). Disk is scaled separately. If your database is not on Isolated Compute, this command will also move a database from a different hosting model to the Isolated Compute hosting model.

Note that since the host flavor selection includes CPU and RAM sizes (b3c.4x16.encrypted is 4 CPU and 16 RAM), this request does not accept both an Isolated size selection and separate CPU and RAM allocation selections.

ibmcloud cdb deployment-groups-set <deploymentid> <groupid> [--disk <val>] [--hostflavor <hostflavor>]

For example, use the following to scale to an Isolated Compute instance or scale up your Isolated Compute instance:

ibmcloud cdb deployment-groups-set crn:abc ... xyz:: member  --hostflavor b3c.8x32.encrypted

CPU and RAM autoscaling is not supported on Cloud Databases Isolated Compute. Disk autoscaling is available. If you provisioned an isolated instance or switched over from a deployment with autoscaling, monitor your resources using IBM Cloud® Monitoring integration, which provides metrics for memory, disk space, and disk I/O utilization. To add resources to your instance, manually scale your deployment.

Review current resources and hosting model

The Foundation endpoint that is shown on the Overview panel of your service provides the base URL to access this deployment through the API. Use it with the /groups endpoint if you need to manage or automate scaling programmatically.

To view the current and scalable resources on a deployment, use the /deployments/{id}/groups endpoint. Note that this command will also reveal if your database is a Shared Compute or Isolated Compute instance through the host_flavor attribute. If the host_flavor is null, it is on an old style hosting model.

curl -X GET https://api.{region}.databases.cloud.ibm.com/v5/ibm/deployments/{id}/groups -H 'Authorization: Bearer <>' \

Scaling with the API

To scale the memory of a deployment to 4096 MB of RAM for each memory member (for a total memory of 12288 MB), use the following command:

curl -X PATCH https://api.{region}.databases.cloud.ibm.com/v5/ibm/deployments/{id}/groups/member 
-H 'Authorization: Bearer <>' 
-H 'Content-Type: application/json' 
-d '{"memory": {"allocation_mb": 12288}}' \

For more information, see the API reference.

Determine the hosting model of your database

Use the following command to review the value of the host_flavor attribute. This will be null if the database is on a deprecated hosting model (not Shared or Isolated Compute).

curl -X GET https://api.{region}.databases.cloud.ibm.com/v5/ibm/deployments/{id}/groups 
-H 'Authorization: Bearer <>' \

Switching to and between Hosting Models in the API

To scale any Cloud Databases Shared Compute instance, use the the following command, setting host_flavor to multitenant. If your database is not on Shared Compute, this command will also move a database from a different hosting model to the Shared Compute hosting model.

curl -X PATCH https://api.{region}.databases.cloud.ibm.com/v5/ibm/deployments/{id}/groups/member
-H 'Authorization: Bearer <>'
-H 'Content-Type: application/json'
-d '{"host_flavor": {"id": "multitenant"},
     "cpu": {"allocation_count": 3},
     "memory": {"allocation_mb": 12288}
    }' \

To scale any instance into a Cloud Databases Isolated Compute instance or to scale to a different Isolated Compute size, use the host_flavor parameter, this time set to the desired Isolated Compute size. Available hosting sizes and their host_flavor value parameters are listed in Table 1. For example, {"host_flavor": "b3c.4x16.encrypted"}. Note that since the host flavor selection includes CPU and RAM sizes (b3c.4x16.encrypted is 4 CPU and 16 RAM), this request does not accept both, an Isolated size selection and separate CPU and RAM allocation selections. Scale with the Cloud Databases API Scaling endpoint, with a command like:

curl -X PATCH https://api.{region}.databases.cloud.ibm.com/v5/ibm/deployments/{id}/groups/member
-H 'Authorization: Bearer <>'
-H 'Content-Type: application/json'
-d '{"host_flavor": {"id": "b3c.4x16.encrypted"}}' \

CPU and RAM allocation is not allowed when provisioning or scaling through Isolated Compute. Specify mulitenant for the host_flavor parameter to have independent CPU and RAM selections.

CPU and RAM autoscaling is not supported on Cloud Databases Isolated Compute. Disk autoscaling is available. If you have provisioned an Isolated instance or switched over from a deployment with autoscaling, keep an eye on your resources using IBM Cloud® Monitoring integration, which provides metrics for memory, disk space, and disk I/O utilization. To add resources to your instance, manually scale your deployment.

Review current resources and hosting model

Review resource allocations to your database by checking your terraform scripts for cpu { allocation_count = }, memory {allocation_mb = }, and disk { allocation_mb = }. Review the host_flavor setting to determine if your database is a Shared Compute or Isolated Compute style hosting model. If host_flavor does not exist, your database is on an old style hosting model.

Scaling with Terraform

Before executing a Terraform script on an existing instance, use the terraform plan command to compare the current infrastructure state with the desired state defined in your Terraform files. Any alteration to the resource_group_id, service plan, version, key_protect_instance, key_protect_key, backup_encryption_key_crn attributes recreates your instance. For a list of current argument references with the Forces new resource specification, see the ibm_database Terraform Registry.

Scale your instance by adjusting your Terraform script for the resource you're interested in. In the following example, cpu, memory, and disk allocations are specified. Note that if you have a host flavor selected (Isolated Compute or Shared Compute Multitenant), keep the host flavor selection in your script.

To implement your change, run terraform apply.

data "ibm_resource_group" "group" {
  name = "<your_group>"
}
resource "ibm_database" "<your_database>" {
  name              = "<your_database_name>"
  plan              = "standard"
  location          = "eu-gb"
  service           = "databases-for-mongodb"
  resource_group_id = data.ibm_resource_group.group.id
  tags              = ["tag1", "tag2"]
  adminpassword     = "password12"
  group {
    group_id = "member"
    cpu {
      allocation_count = 6
    }
    memory {
      allocation_mb = 24576
    }
    disk {
      allocation_mb = 256000
    }
  }
  users {
    name     = "user123"
    password = "password12"
  }
  allowlist {
    address     = "172.168.1.1/32"
    description = "desc"
  }
}
output "ICD MongoDB database connection string" {
  value = "http://${ibm_database.test_acc.ibm_database_connection.icd_conn}"
}

Switching to and Scaling Hosting Models in Terraform

Select the hosting model you want your database to be scaled to. You can change this later.

To scale your Databases for MongoDB instance to the Shared Compute hosting flavor, set the "host_flavor" parameter to multitenant. This works if you want to scale to the Shared Compute hosting flavor, or if you want to keep the host flavor and scale your resources. To implement your change, run terraform apply.

See the following example:

data "ibm_resource_group" "group" {
  name = "<your_group>"
}
resource "ibm_database" "<your_database>" {
  name              = "<your_database_name>"
  plan              = "standard"
  location          = "eu-gb"
  service           = "databases-for-mongodb"
  resource_group_id = data.ibm_resource_group.group.id
  tags              = ["tag1", "tag2"]
  adminpassword     = "password12"
  group {
    group_id = "member"
    host_flavor {
      id = "multitenant"
    },
    cpu {
      allocation_count = 6
    }
    memory {
      allocation_mb = 24576
    }
    disk {
      allocation_mb = 256000
    }
  }
  users {
    name     = "user123"
    password = "password12"
  }
  allowlist {
    address     = "172.168.1.1/32"
    description = "desc"
  }
}
output "ICD MongoDB database connection string" {
  value = "http://${ibm_database.test_acc.ibm_database_connection.icd_conn}"
}

Scale your Databases for MongoDB instance to Isolated Compute with the same "host_flavor" parameter, set to the desired Isolated size. This command works to scale your database instance to a different Isolated Compute size, as well as to move from another host flavor to the Isolated Compute host flavor. Available hosting sizes and their host_flavor value parameters are listed in Table 1. For example, {"host_flavor": "b3c.4x16.encrypted"}. Note that since the host flavor selection includes CPU and RAM sizes (b3c.4x16.encrypted is 4 CPU and 16 RAM), this request does not accept both an Isolated size selection and separate CPU and RAM allocation selections.

To implement your change, run terraform apply.

data "ibm_resource_group" "group" {
  name = "<your_group>"
}
resource "ibm_database" "<your_database>" {
  name              = "<your_database_name>"
  plan              = "standard"
  location          = "eu-gb"
  service           = "databases-for-mongodb"
  resource_group_id = data.ibm_resource_group.group.id
  tags              = ["tag1", "tag2"]
  adminpassword     = "password12"
  group {
    group_id = "member"
    host_flavor {
      id = "b3c.8x32.encrypted"
    }
    disk {
      allocation_mb = 256000
    }
  }
  users {
    name     = "user123"
    password = "password12"
  }
  allowlist {
    address     = "172.168.1.1/32"
    description = "desc"
  }
}
output "ICD MongoDB database connection string" {
  value = "http://${ibm_database.test_acc.ibm_database_connection.icd_conn}"
}