Create a backend group

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Creating a backend group with a target group
Create a backend group with a bucket

When creating a backend group, you can add two types of backends to it: backends with target groups and with Object Storage buckets.

Creating a backend group with a target group

Create a backend group by following the instructions.

To create a backend group with a target group:

Management console

CLI

Terraform

In the management console, select the folder to create your backend group in.
In the list of services, select Application Load Balancer.
On the left-hand panel, select Backend groups.
Click Create backend group.
Enter the backend group name: test-backend-group.
Select the backend group type:
- HTTP: For HTTP or HTTPS traffic.
- gRPC: For HTTP or HTTPS traffic with a gRPC call.
- Stream: For unencrypted TCP traffic or TCP traffic with TLS encryption support.
Alert

You can only select a backend group's type when creating it. You can't change the type of an existing group.
(optional) For an HTTP or gRPC backend group, enable Session affinity. The following modes are available:
- By IP address.
- By HTTP header.
- By cookie.
  
  Note
  
  Currently, session affinity only works if a single backend is active (has a positive weight) in a group of backends, includes one or more target groups, and the MAGLEV_HASH load balancing mode is selected for it.
Under Backends, click Add. Specify the backend settings:
- Enter the backend name: test-backend-1.
- Set the weight of the backend: 1.
- Select the Target group backend type for an HTTP backend group. In a gRPC or Stream backend group, only target groups and their sets can act as backends.
- In the Target groups list, select test-target-group and set the Port to 80.
Expand the Load balancing settings field and set the parameters:
- Threshold for panic mode: 90.
- Locality aware routing: 90.
Expand the Protocol settings field and select the HTTP type. By default, HTTP/1.1 is used for HTTP backend groups. To use HTTP/2, select the HTTP/2 option. Backend groups of the gRPC type only support HTTP/2 connections.
Click Add health check and configure the check:
- Timeout: 1.
- Interval: 1.
- Healthy threshold: 3.
- Unhealthy threshold: 10.
- Type: HTTP.
  
  Note
  
  Health checks of the HTTP, gRPC, and Stream types are supported. They match the backend group types. However, the type of a health check doesn't have to be the same as the group type.
- Path: /.
Click Create.

If you don't have the Yandex Cloud command line interface yet, install and initialize it.

The folder specified in the CLI profile is used by default. You can specify a different folder using the --folder-name or --folder-id parameter.

Note

You can create a gRPC backend group in the management console or using Terraform.

View a description of the CLI command to create a backend group:
```
yc alb backend-group create --help
```

Create a backend group by running the command:

yc alb backend-group create <backend group name>

Result:

id: a5dg2cv4ngne8575fb1p
name: test-backend-group
folder_id: aoerb349v3h4bupphtaf
created_at: "2021-02-11T20:46:21.688940670Z"

Add a backend and health check to the group. All backends within the group must have the same type: HTTP or Stream.

HTTP backend

Run the command:

yc alb backend-group add-http-backend \
  --backend-group-name <name of the backend group> \
  --name <name of the backend to be added> \
  --weight <backend weight> \
  --port <backend port> \
  --target-group-id=<target group ID> \
  --panic-threshold 90 \
  --http-healthcheck port=80,healthy-threshold=10,unhealthy-threshold=15, \
timeout=10s,interval=2s,host=your-host.com,path=/ping

Where:

--panic-threshold: The threshold for panic mode.
--http-healthcheck: Parameters for checking the resource status:
- port: The port.
- healthy-threshold: The healthy threshold.
- unhealthy-threshold: The unhealthy threshold.
- timeout: The timeout.
- interval: The interval.
- host: The host address.
- path: The path.

Result:

id: a5dqkr2mk3rr799f1npa
name: test-backend-group
folder_id: aoe197919j8elpeg1lkp
http:
  backends:
  - name: backend1
    backend_weight: "1"
    load_balancing_config:
      panic_threshold: "90"
    port: "80"
    target_groups:
      target_group_ids:
      - a5d2iap3nue9s3anblu6
    healthchecks:
    - timeout: 10s
      interval: 2s
      healthy_threshold: "10"
      unhealthy_threshold: "15"
      healthcheck_port: "80"
      http:
        host: your-host.com
        path: /ping
created_at: "2021-02-11T20:46:21.688940670Z"

Stream backend

Run the command:

yc alb backend-group add-stream-backend \
  --backend-group-name <name of the backend group> \
  --name <name of the backend to be added> \
  --weight <backend weight> \
  --port <backend port> \
  --target-group-id=<target group ID> \
  --panic-threshold 90 \
  --http-healthcheck port=80,healthy-threshold=10,unhealthy-threshold=15,\
timeout=10s,interval=2s,host=your-host.com,path=/ping

Where:

--panic-threshold: The threshold for panic mode.
--http-healthcheck: Parameters for checking the resource status:
- port: The port.
- healthy-threshold: The healthy threshold.
- unhealthy-threshold: The unhealthy threshold.
- timeout: The timeout.
- interval: The interval.
- host: The host address.
- path: The path.

Result:

id: ds77tero4f5h46l4e2gl
name: test-backend-group
folder_id: b1gu6g9ielh690at5bm7
stream:
  backends:
  - name: stream-backend
backend_weight: "1"
    port: "80"
    target_groups:
      target_group_ids:
      - ds7eof3r2cte9u069p97
    healthchecks:
    - timeout: 10s
      interval: 2s
      healthy_threshold: "10"
      unhealthy_threshold: "15"
      healthcheck_port: "80"
      http:
        host: your-host.com
        path: /ping
created_at: "2022-04-06T09:17:57.104324513Z"

With Terraform, you can quickly create a cloud infrastructure in Yandex Cloud and manage it by configuration files. They store the infrastructure description in HashiCorp Configuration Language (HCL). Terraform and its providers are distributed under the Mozilla Public License.

For more information about the provider resources, see the documentation on the Terraform site or mirror site.

If you change the configuration files, Terraform automatically determines which part of your configuration is already deployed and what should be added or removed.

For more information about Terraform, see the documentation.

In the Terraform configuration file, describe the parameters of the resource to create:
```
resource "yandex_alb_backend_group" "test-backend-group" {
  name                     = "<backend group name>"

  http_backend {
    name                   = "<backend name>"
    weight                 = 1
    port                   = 80
    target_group_ids       = ["<target group ID>"]
    load_balancing_config {
      panic_threshold      = 90
    }    
    healthcheck {
      timeout              = "10s"
      interval             = "2s"
      healthy_threshold    = 10
      unhealthy_threshold  = 15 
      http_healthcheck {
        path               = "/"
      }
    }
  }
}
```
Where:
- yandex_alb_backend_group specifies the backend group parameters:
- name: Backend group name.
- http_backend, grpc_backend, and stream_backend: Backend type. All backends within the group must have the same type: HTTP, gRPC, or Stream.
Backend parameters:
- name: Backend name.
- port: Backend port.
- weight: Backend weight.
- target_group_ids: Target group ID. To get a list of available target groups, run the following CLI command: yc alb target-group list.
- load_balancing_config: Load balancing settings:
  - panic_threshold: Threshold for panic mode.
- healthcheck: Health check parameters:
  - timeout: The timeout.
  - interval: The interval.
  - healthy_threshold: The healthy threshold.
  - unhealthy_threshold: The unhealthy threshold.
  - http_healthcheck: Parameters for HTTP health checks:
    - path: The path.
For more information about the yandex_alb_backend_group resource parameters, see the Terraform provider documentation.
Create resources:
1. In the command line, go to the directory with the Terraform configuration file.
2. Check the configuration using the command:
```
terraform validate
```
  If the configuration is correct, the following message is returned:
```
Success! The configuration is valid.
```
3. Run the command:
```
terraform plan
```
  The terminal will display a list of resources with parameters. No changes are made at this step. If there are errors in the configuration, Terraform points them out.
4. Apply the configuration changes:
```
terraform apply
```
5. Confirm the changes: type yes into the terminal and press Enter.
Terraform creates all the required resources. You can check that the resources are there using the management console or the CLI command below:
```
yc alb backend-group list
```