<p>Do you have a subnet in ap-southwest-2c? In order to build the the Subnet group for RDS you have to have subnets in all AZs. If you don't have, Terraform throws this error received from API.</p>

CC BY-SA 4.0
2022-12-11T16:02:29.143Z
2022-12-11T16:02:29.143Z
Pawel Piwosz
<p>I'm attempting to create an AWS RDS Serverless v2 cluster in region <code>ap-southeast-2</code> (Sydney) using the following Terraform configuration:</p>
<pre><code>provider &quot;aws&quot; {
  region = &quot;ap-southeast-2&quot;
}

data &quot;aws_availability_zones&quot; &quot;available&quot; {
  state = &quot;available&quot;
}

resource &quot;aws_rds_cluster&quot; &quot;backend_app_db_cluster&quot; {
  availability_zones = data.aws_availability_zones.available.names
  # ...
}
</code></pre>
<p>When I try to <code>apply</code> this configuration, I get the following error:</p>
<blockquote>
<p>InvalidVPCNetworkStateFault: Availability zone '[ap-southeast-2c]' is unavailable in this region, please choose another zone set.</p>
</blockquote>
<p>Full output:</p>
<pre><code>module.database.aws_rds_cluster.backend_app_db_cluster: Creating...
╷
│ Error: creating RDS Cluster (&lt;munged&gt;20221204221217538100000001): InvalidVPCNetworkStateFault: Availability zone '[ap-southeast-2c]' is unavailable in this region, please choose another zone set.
│   status code: 400, request id: &lt;munged&gt;
│
│   with module.database.aws_rds_cluster.backend_app_db_cluster,
│   on modules/database/main.tf line 54, in resource &quot;aws_rds_cluster&quot; &quot;backend_app_db_cluster&quot;:
│   54: resource &quot;aws_rds_cluster&quot; &quot;backend_app_db_cluster&quot; {
</code></pre>
<p>If I specify the availability zones manually and specifically exclude <code>ap-southeast-2c</code>, it works as expected:</p>
<pre><code>data &quot;aws_availability_zones&quot; &quot;available&quot; {
  exclude_names = [&quot;ap-southeast-2c&quot;]
  state         = &quot;available&quot;
}
</code></pre>
<pre><code>$ terraform apply
...
module.database.aws_rds_cluster_instance.backend_app_db_cluster_instance: Creation complete after 12m43s [id=tf-&lt;munged&gt;]

Apply complete! Resources: 3 added, 0 changed, 1 destroyed.
</code></pre>
<p>Why is <code>aws_availability_zones</code> returning an AZ that's unavailable?</p>

<amazon-web-services><terraform><amazon-rds>
aws_availability_zones returns an availability zone ap-southeast-2c that is not available
todofixthis
# aws_availability_zones returns an availability zone ap-southeast-2c that is not available

(Asked by: username_0 on 2022-12-04)

I'm attempting to create an AWS RDS Serverless v2 cluster in region ap-southeast-2 (Sydney) using the following Terraform configuration:
provider "aws" {
  region = "ap-southeast-2"
}

data "aws_availability_zones" "available" {
  state = "available"
}

resource "aws_rds_cluster" "backend_app_db_cluster" {
  availability_zones = data.aws_availability_zones.available.names
  # ...
}

When I try to apply this configuration, I get the following error:

InvalidVPCNetworkStateFault: Availability zone '[ap-southeast-2c]' is unavailable in this region, please choose another zone set.

Full output:
module.database.aws_rds_cluster.backend_app_db_cluster: Creating...
╷
│ Error: creating RDS Cluster (20221204221217538100000001): InvalidVPCNetworkStateFault: Availability zone '[ap-southeast-2c]' is unavailable in this region, please choose another zone set.
│   status code: 400, request id: 
│
│   with module.database.aws_rds_cluster.backend_app_db_cluster,
│   on modules/database/main.tf line 54, in resource "aws_rds_cluster" "backend_app_db_cluster":
│   54: resource "aws_rds_cluster" "backend_app_db_cluster" {

If I specify the availability zones manually and specifically exclude ap-southeast-2c, it works as expected:
data "aws_availability_zones" "available" {
  exclude_names = ["ap-southeast-2c"]
  state         = "available"
}

$ terraform apply
...
module.database.aws_rds_cluster_instance.backend_app_db_cluster_instance: Creation complete after 12m43s [id=tf-]

Apply complete! Resources: 3 added, 0 changed, 1 destroyed.

Why is aws_availability_zones returning an AZ that's unavailable?

**Tags:** amazon-web-services, terraform, amazon-rds


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## 1 answers

### Answer by username_1 on 2022-12-11. Score: 2

Do you have a subnet in ap-southwest-2c? In order to build the the Subnet group for RDS you have to have subnets in all AZs. If you don't have, Terraform throws this error received from API.


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