[Bug]: aws_elasticache_serverless_cache: ecpu_per_second without a limit block count changed from 1 to 0.

[maxvisser]

Terraform Core Version

1.5.7

AWS Provider Version

5.35.0

Affected Resource(s)

aws_elasticache_serverless_cache

Expected Behavior

Setting ecpu to 0 would mean unlimited

Actual Behavior

Its set it to unlimited but I run into an error after apply

Relevant Error/Panic Output Snippet

│ Error: Provider produced inconsistent result after apply
│ 
│ When applying changes to aws_elasticache_serverless_cache.nhb-redis-staging-1, provider "provider[\"registry.terraform.io/hashicorp/aws\"]" produced an unexpected new value:
│ .cache_usage_limits[0].ecpu_per_second: block count changed from 1 to 0.
│ 
│ This is a bug in the provider, which should be reported in the provider's own issue tracker.

Terraform Configuration Files

resource "aws_elasticache_serverless_cache" "xx-redis-staging-1" {
  engine = "redis"
  name   = "xx-redis-staging-1"
  cache_usage_limits {
    data_storage {
      maximum = 5
      unit    = "GB"
    }
    ecpu_per_second {
      maximum = 0
    }
  }
  daily_snapshot_time      = "09:00"
  description              = "Redis for xx Staging"
  major_engine_version     = "7"
  snapshot_retention_limit = 1
  security_group_ids = [aws_security_group.elasticache_sg.id]
  subnet_ids = ["subnet-xx","subnet-xx", "subnet-xx"]
  user_group_id = aws_elasticache_user_group.nhbGroup.user_group_id
}

Steps to Reproduce

apply a aws_elasticache_serverless_cache resource with
ecpu_per_second {
maximum = 0
}

Debug Output

No response

Panic Output

No response

Important Factoids

No response

References

No response

Would you like to implement a fix?

None

[github-actions]

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[meetreks]

I checked in Console but it does not allow me to put a 0 in Max
This is thee error I am getting on the console

ElastiCache Processing Units (ECPUs) limit is out of range.
You can set a maximum limit between 1,000 and 15,000,000 ECPUs per second.

[mshahmoradi87]

I checked in Console but it does not allow me to put a 0 in Max This is thee error I am getting on the console

ElastiCache Processing Units (ECPUs) limit is out of range. You can set a maximum limit between 1,000 and 15,000,000 ECPUs per second.

true, but if possible with 0, module should not try to set it, as a workaround I have defined this block like below:

  dynamic "cache_usage_limits" {
    for_each = (var.max_storage_gb >= 1 || var.max_epu_per_second >= 1000) ? [1] : []

    content {
      dynamic "data_storage" {
        for_each = var.max_storage_gb >= 1 ? [1] : []
        content {
          maximum = var.max_storage_gb
          unit    = "GB"
        }
      }

      dynamic "ecpu_per_second" {
        for_each = var.max_epu_per_second >= 1000 ? [1] : []
        content {
          maximum = var.max_epu_per_second
        }
      }
    }
  }

[meetreks]

If you want I can put a validation which will error on Plan stage, is this Ok @mshahmoradi87

[meetreks]

Added limits as mentioned above

[stegosaurus21]

Hi, I am also encountering this issue. According to AWS CLI documentation, setting these values to zero seems to be the intended way to indicate an unlimited resource cap.

In general, there doesn't seem to be a way in the module at the moment to set only a ECPU or data storage limit without setting the other as well.

[maxvisser]

Hi, I am also encountering this issue. According to AWS CLI documentation, setting these values to zero seems to be the intended way to indicate an unlimited resource cap.

In general, there doesn't seem to be a way in the module at the moment to set only a ECPU or data storage limit without setting the other as well.

This was indeed the issue that I was having too. Not sure with the current validation fix how to set it to unlimited..

[github-actions]

This functionality has been released in v5.40.0 of the Terraform AWS Provider. Please see the Terraform documentation on provider versioning or reach out if you need any assistance upgrading.

For further feature requests or bug reports with this functionality, please create a new GitHub issue following the template. Thank you!

[github-actions]

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues.
If you have found a problem that seems similar to this, please open a new issue and complete the issue template so we can capture all the details necessary to investigate further.