In this tutorial, you will add a second origin for some basic round robining, and then use the [Cloudflare Load Balancing](https://developers.cloudflare.com/load-balancing/) product to fail traffic over as needed. You will also enhance your load balancing configuration through the use of "geo steering" to serve results from an origin server that is geographically closest to your end users.

Note

Terraform code snippets below refer to the v4 SDK only.

## 1. Add another DNS record for `www`

To get started, add a DNS record for a second web server, located in Asia. The IP address for this server is `198.51.100.15`.

```bash
git checkout -b step4-loadbalance
```

```bash
Switched to a new branch 'step4-loadbalance'
```

```bash
cat >> cloudflare.tf <<'EOF'
resource "cloudflare_record" "www-asia" {
  zone_id = var.zone_id
  name    = "www"
  value   = "198.51.100.15"
  type    = "A"
  proxied = true
}
EOF
```

Note that while the name of the `resource` is different because Terraform resources of the same type must be uniquely named, the DNS name, or what your customers will type in their browser, is the same: `www`.

## 2. Preview and merge the changes

Check the `terraform plan` and then merge and apply the changes.

```sh
terraform plan | grep -v "(known after apply)"
```

```sh
Refreshing Terraform state in-memory prior to plan...
The refreshed state will be used to calculate this plan, but will not be
persisted to local or remote state storage.


cloudflare_record.www: Refreshing state... [id=c38d3103767284e7cd14d5dad3ab8669]
cloudflare_zone_settings_override.example-com-settings: Refreshing state... [id=e2e6491340be87a3726f91fc4148b126]


------------------------------------------------------------------------


An execution plan has been generated and is shown below.
Resource actions are indicated with the following symbols:
  + create


Terraform will perform the following actions:


  # cloudflare_record.www-asia will be created
  + resource "cloudflare_record" "www-asia" {
      + allow_overwrite = false
      + name            = "www"
      + proxied         = true
      + type            = "A"
      + value           = "198.51.100.15"
      + zone_id         = "e2e6491340be87a3726f91fc4148b126"
    }


Plan: 1 to add, 0 to change, 0 to destroy.


------------------------------------------------------------------------


Note: You didn't use the -out option to save this plan, so Terraform can't
guarantee to take exactly these actions if you run "terraform apply" now.
```

```sh
git add cloudflare.tf
git commit -m "Step 4 - Add additional 'www' DNS record for Asia data center."
```

```sh
[step4-loadbalance 6761a4f] Step 4 - Add additional 'www' DNS record for Asia data center.
 1 file changed, 7 insertions(+)
```

```sh
git checkout master
```

```sh
Switched to branch 'master'
```

```sh
git merge step4-loadbalance
```

```sh
Updating e1c38cf..6761a4f
Fast-forward
 cloudflare.tf | 7 +++++++
 1 file changed, 7 insertions(+)
```

## 3. Apply and verify the changes

Add the second DNS record for [www.example.com](http://www.example.com).

```sh
terraform apply --auto-approve
```

```sh
cloudflare_record.www: Refreshing state... [id=c38d3103767284e7cd14d5dad3ab8668]
cloudflare_zone_settings_override.example-com-settings: Refreshing state... [id=e2e6491340be87a3726f91fc4148b126]


Terraform used the selected providers to generate the following execution plan.
Resource actions are indicated with the following symbols:
  + create


Terraform will perform the following actions:


  # cloudflare_record.www-asia will be created
  + resource "cloudflare_record" "www-asia" {
      + allow_overwrite = false
      + created_on      = (known after apply)
      + hostname        = (known after apply)
      + id              = (known after apply)
      + metadata        = (known after apply)
      + modified_on     = (known after apply)
      + name            = "www"
      + proxiable       = (known after apply)
      + proxied         = true
      + ttl             = (known after apply)
      + type            = "A"
      + value           = "198.51.100.15"
      + zone_id         = "e2e6491340be87a3726f91fc4148b126"
    }


Plan: 1 to add, 0 to change, 0 to destroy.
cloudflare_record.www-asia: Creating...
cloudflare_record.www-asia: Creation complete after 1s [id=fda39d8c9bf909132e82a36bab992864]


Apply complete! Resources: 1 added, 0 changed, 0 destroyed.
```

With the second DNS record in place, make some requests to see where the traffic is served from.

```sh
curl https://www.example.com
```

```sh
Hello, this is 203.0.113.10!
```

```sh
curl https://www.example.com
```

```sh
Hello, this is 203.0.113.10!
```

```sh
curl https://www.example.com
```

```sh
Hello, this is 198.51.100.15!
```

```sh
curl https://www.example.com
```

```sh
Hello, this is 203.0.113.10!
```

As noted above, there is no discernible pattern for which origin receives the request. When Cloudflare connects to an origin with multiple DNS records, one of the IP addresses is selected at random. If both IPs are in the same data center and sessions can be shared (that is, it does not matter if the same user hops between origin servers), this may work fine. However, for anything more complicated, such as origins in different geographies or active health checks, you will want to use Cloudflare's Load Balancing product.

## 4. Switch to using Cloudflare's Load Balancing product

Note

Before proceeding, ensure [Load Balancing is enabled for your account](https://developers.cloudflare.com/load-balancing/get-started/enable-load-balancing/).

As described in the [Load Balancing tutorial](https://developers.cloudflare.com/learning-paths/load-balancing/concepts/), you will need to complete three tasks:

1. Create a monitor to run health checks against your origin servers.
2. Create a pool of one or more origin servers that will receive load balanced traffic.
3. Create a load balancer with an external hostname — for example, `www.example.com` — and one or more pools.

### i. Define and create the health check ("monitor")

To monitor the origins, create a basic health check that makes a `GET` request to each origin on the URL `https://www.example.com`. If the origin returns the `200` status code (`OK`) within five seconds, it is considered healthy. If it fails to do so three times in a row, it is considered unhealthy. This health check will be run once per minute from several regions and send an email notification to your email address (configured as `<YOUR_EMAIL>`) if any failures are detected.

```bash
git checkout step4-loadbalance
```

```bash
Switched to branch 'step4-loadbalance'
```

```bash
cat >> cloudflare.tf <<'EOF'


resource "cloudflare_load_balancer_monitor" "get-root-https" {
  account_id     = var.account_id
  expected_body  = "alive"
  expected_codes = "200"
  method         = "GET"
  timeout        = 5
  path           = "/"
  interval       = 60
  retries        = 2
  description    = "GET / over HTTPS - expect 200"
}
EOF
```

### ii. Define and create the pool of origins

In this example, the pool will be called `www-servers` with two origins added to it:

* `www-us` (`203.0.113.10`)
* `www-asia` (`198.51.100.15`)

For now, skip any sort of [geo routing](https://developers.cloudflare.com/load-balancing/understand-basics/traffic-steering/steering-policies/geo-steering/).

Note the reference to the monitor that you added in the last step. When applying this configuration, Terraform will determine that it first needs to create the monitor before looking up the ID and providing it to the pool you wish to create.

```bash
cat >> cloudflare.tf <<'EOF'


resource "cloudflare_load_balancer_pool" "www-servers" {
  account_id = var.account_id
  name       = "www-servers"
  monitor    = cloudflare_load_balancer_monitor.get-root-https.id
  origins {
    name    = "www-us"
    address = "203.0.113.10"
  }
  origins {
    name    = "www-asia"
    address = "198.51.100.15"
  }
  description        = "www origins"
  enabled            = true
  minimum_origins    = 1
  notification_email = "<YOUR_EMAIL>"
  check_regions      = ["WNAM", "ENAM", "WEU", "EEU", "SEAS", "NEAS"]
}
EOF
```

### iii. Define and create the load balancer

When you create a load balancer (LB), it will [replace any existing DNS records with the same name](https://developers.cloudflare.com/load-balancing/load-balancers/dns-records/). For example, if you create the `www.example.com` load balancer below, it will supersede the two `www` DNS records that you previously defined. One benefit of leaving the DNS records in place is that if you temporarily disable load balancing, connections to this hostname are still possible as shown in [step 2](#2-preview-and-merge-the-changes) above.

```bash
cat >> cloudflare.tf <<'EOF'


resource "cloudflare_load_balancer" "www-lb" {
  zone_id          = var.zone_id
  name             = "www-lb"
  default_pool_ids = [cloudflare_load_balancer_pool.www-servers.id]
  fallback_pool_id = cloudflare_load_balancer_pool.www-servers.id
  description      = "example load balancer"
  proxied          = true
}
EOF
```

### iv. Preview and merge the changes

As usual, review the proposed plan before applying any changes.

```sh
terraform plan
```

```sh
cloudflare_record.www: Refreshing state... [id=c38d3103767284e7cd14d5dad3ab8669]
cloudflare_record.www-asia: Refreshing state... [id=fda39d8c9bf909132e82a36bab992864]
cloudflare_zone_settings_override.example-com-settings: Refreshing state... [id=e2e6491340be87a3726f91fc4148b126]


Terraform used the selected providers to generate the following execution plan.
Resource actions are indicated with the following symbols:
  + create


Terraform will perform the following actions:


  # cloudflare_load_balancer.www-lb will be created
  + resource "cloudflare_load_balancer" "www-lb" {
      + created_on       = (known after apply)
      + default_pool_ids = (known after apply)
      + description      = "example load balancer"
      + enabled          = true
      + fallback_pool_id = (known after apply)
      + id               = (known after apply)
      + modified_on      = (known after apply)
      + name             = "www-lb"
      + proxied          = true
      + session_affinity = "none"
      + steering_policy  = (known after apply)
      + ttl              = (known after apply)
      + zone_id          = "e2e6491340be87a3726f91fc4148b126"


      + country_pools {
          + country  = (known after apply)
          + pool_ids = (known after apply)
        }


      + pop_pools {
          + pool_ids = (known after apply)
          + pop      = (known after apply)
        }


      + region_pools {
          + pool_ids = (known after apply)
          + region   = (known after apply)
        }
    }


  # cloudflare_load_balancer_monitor.get-root-https will be created
  + resource "cloudflare_load_balancer_monitor" "get-root-https" {
      + account_id     = "8baedd8d98bf4b0c9bc650acc307b441"
      + created_on     = (known after apply)
      + description    = "GET / over HTTPS - expect 200"
      + expected_body  = "alive"
      + expected_codes = "200"
      + id             = (known after apply)
      + interval       = 60
      + method         = "GET"
      + modified_on    = (known after apply)
      + path           = "/"
      + retries        = 2
      + timeout        = 5
      + type           = "http"
    }


  # cloudflare_load_balancer_pool.www-servers will be created
  + resource "cloudflare_load_balancer_pool" "www-servers" {
      + account_id    = "8baedd8d98bf4b0c9bc650acc307b441"
      + check_regions = [
          + "EEU",
          + "ENAM",
          + "NEAS",
          + "SEAS",
          + "WEU",
          + "WNAM",
        ]
      + created_on         = (known after apply)
      + description        = "www origins"
      + enabled            = true
      + id                 = (known after apply)
      + minimum_origins    = 1
      + modified_on        = (known after apply)
      + monitor            = (known after apply)
      + name               = "www-servers"
      + notification_email = "<YOUR_EMAIL>"


      + origins {
          + address = "198.51.100.15"
          + enabled = true
          + name    = "www-asia"
          + weight  = 1
        }
      + origins {
          + address = "203.0.113.10"
          + enabled = true
          + name    = "www-us"
          + weight  = 1
        }
    }


Plan: 3 to add, 0 to change, 0 to destroy.


------------------------------------------------------------------------


Note: You didn't use the -out option to save this plan, so Terraform can't
guarantee to take exactly these actions if you run "terraform apply" now.
```

The plan looks good. Merge the plan and apply it.

```sh
git add cloudflare.tf
git commit -m "Step 4 - Create load balancer (LB) monitor, LB pool, and LB."
```

```sh
[step4-loadbalance bc9aa9a] Step 4 - Create load balancer (LB) monitor, LB pool, and LB.
 1 file changed, 35 insertions(+)
```

```sh
terraform apply --auto-approve
```

```sh
cloudflare_zone_settings_override.example-com-settings: Refreshing state... [id=e2e6491340be87a3726f91fc4148b126]
cloudflare_record.www: Refreshing state... [id=c38d3103767284e7cd14d5dad3ab8669]
cloudflare_record.www-asia: Refreshing state... [id=fda39d8c9bf909132e82a36bab992864]


Terraform used the selected providers to generate the following execution plan.
Resource actions are indicated with the following symbols:
  + create


Terraform will perform the following actions:


  # cloudflare_load_balancer.www-lb will be created
  + resource "cloudflare_load_balancer" "www-lb" {
      + created_on       = (known after apply)
      + default_pool_ids = (known after apply)
      + description      = "example load balancer"
      + enabled          = true
      + fallback_pool_id = (known after apply)
      + id               = (known after apply)
      + modified_on      = (known after apply)
      + name             = "www-lb"
      + proxied          = true
      + session_affinity = "none"
      + steering_policy  = (known after apply)
      + ttl              = (known after apply)
      + zone_id          = "e2e6491340be87a3726f91fc4148b126"


      + country_pools {
          + country  = (known after apply)
          + pool_ids = (known after apply)
        }


      + pop_pools {
          + pool_ids = (known after apply)
          + pop      = (known after apply)
        }


      + region_pools {
          + pool_ids = (known after apply)
          + region   = (known after apply)
        }
    }


  # cloudflare_load_balancer_monitor.get-root-https will be created
  + resource "cloudflare_load_balancer_monitor" "get-root-https" {
      + account_id     = "8baedd8d98bf4b0c9bc650acc307b441"
      + created_on     = (known after apply)
      + description    = "GET / over HTTPS - expect 200"
      + expected_body  = "alive"
      + expected_codes = "200"
      + id             = (known after apply)
      + interval       = 60
      + method         = "GET"
      + modified_on    = (known after apply)
      + path           = "/"
      + retries        = 2
      + timeout        = 5
      + type           = "http"
    }


  # cloudflare_load_balancer_pool.www-servers will be created
  + resource "cloudflare_load_balancer_pool" "www-servers" {
      + account_id      = "8baedd8d98bf4b0c9bc650acc307b441"
      + check_regions   = [
          + "EEU",
          + "ENAM",
          + "NEAS",
          + "SEAS",
          + "WEU",
          + "WNAM",
        ]
      + created_on         = (known after apply)
      + description        = "www origins"
      + enabled            = true
      + id                 = (known after apply)
      + minimum_origins    = 1
      + modified_on        = (known after apply)
      + monitor            = (known after apply)
      + name               = "www-servers"
      + notification_email = "<YOUR_EMAIL>"


      + origins {
          + address = "198.51.100.15"
          + enabled = true
          + name    = "www-asia"
          + weight  = 1
        }
      + origins {
          + address = "203.0.113.10"
          + enabled = true
          + name    = "www-us"
          + weight  = 1
        }
    }


cloudflare_load_balancer_monitor.get-root-https: Creating...
cloudflare_load_balancer_monitor.get-root-https: Creation complete after 1s [id=4238142473fcd48e89ef1964be72e3e0]
cloudflare_load_balancer_pool.www-servers: Creating...
cloudflare_load_balancer_pool.www-servers: Creation complete after 0s [id=906d2a7521634783f4a96c062eeecc6d]
cloudflare_load_balancer.www-lb: Creating...
cloudflare_load_balancer.www-lb: Creation complete after 1s [id=cb94f53f150e5c1a65a07e43c5d4cac4]


Apply complete! Resources: 3 added, 0 changed, 0 destroyed.
```

### v. Test the changes

With load balancing in place, run four `curl` requests again to see where the traffic is served from.

```sh
for i in {1..4}; do curl https://www.example.com && sleep 5; done
```

```sh
Hello, this is 198.51.100.15!


Hello, this is 203.0.113.10!


Hello, this is 198.51.100.15!


Hello, this is 203.0.113.10!
```

You should now see each request load balanced evenly across the two origins you defined.
