# Reviewing environment variables reference
Environment variables reference

The following environment variables are defined and used in the tutorial of [Setting up multiple controller nodes for a SageMaker HyperPod Slurm cluster](sagemaker-hyperpod-multihead-slurm-setup.md). These environment variables are only available in the current session unless explicitly preserved. They are defined using the `$variable_name` syntax. Variables with key/value pairs represent Amazon-created resources, while variables without keys are user-defined.


**Environment variables reference**  

| Variable | Description | 
| --- | --- | 
| \$1BACKUP\$1SUBNET |  [\[See the AWS documentation website for more details\]](http://docs.amazonaws.cn/en_us/sagemaker/latest/dg/sagemaker-hyperpod-multihead-slurm-variables-reference.html)  | 
| \$1COMPUTE\$1IG\$1NAME |  [\[See the AWS documentation website for more details\]](http://docs.amazonaws.cn/en_us/sagemaker/latest/dg/sagemaker-hyperpod-multihead-slurm-variables-reference.html)  | 
| \$1COMPUTE\$1NODE\$1ROLE |  [\[See the AWS documentation website for more details\]](http://docs.amazonaws.cn/en_us/sagemaker/latest/dg/sagemaker-hyperpod-multihead-slurm-variables-reference.html)  | 
| \$1CONTOLLER\$1IG\$1NAME |  [\[See the AWS documentation website for more details\]](http://docs.amazonaws.cn/en_us/sagemaker/latest/dg/sagemaker-hyperpod-multihead-slurm-variables-reference.html)  | 
| \$1DB\$1USER\$1NAME |  [\[See the AWS documentation website for more details\]](http://docs.amazonaws.cn/en_us/sagemaker/latest/dg/sagemaker-hyperpod-multihead-slurm-variables-reference.html)  | 
| \$1EMAIL |  [\[See the AWS documentation website for more details\]](http://docs.amazonaws.cn/en_us/sagemaker/latest/dg/sagemaker-hyperpod-multihead-slurm-variables-reference.html)  | 
| \$1PRIMARY\$1SUBNET |  [\[See the AWS documentation website for more details\]](http://docs.amazonaws.cn/en_us/sagemaker/latest/dg/sagemaker-hyperpod-multihead-slurm-variables-reference.html)  | 
| \$1POLICY |  [\[See the AWS documentation website for more details\]](http://docs.amazonaws.cn/en_us/sagemaker/latest/dg/sagemaker-hyperpod-multihead-slurm-variables-reference.html)  | 
| \$1REGION |  [\[See the AWS documentation website for more details\]](http://docs.amazonaws.cn/en_us/sagemaker/latest/dg/sagemaker-hyperpod-multihead-slurm-variables-reference.html)  | 
| \$1ROOT\$1BUCKET\$1NAME |  [\[See the AWS documentation website for more details\]](http://docs.amazonaws.cn/en_us/sagemaker/latest/dg/sagemaker-hyperpod-multihead-slurm-variables-reference.html)  | 
| \$1SECURITY\$1GROUP |  [\[See the AWS documentation website for more details\]](http://docs.amazonaws.cn/en_us/sagemaker/latest/dg/sagemaker-hyperpod-multihead-slurm-variables-reference.html)  | 
| \$1SLURM\$1DB\$1ENDPOINT\$1ADDRESS |  [\[See the AWS documentation website for more details\]](http://docs.amazonaws.cn/en_us/sagemaker/latest/dg/sagemaker-hyperpod-multihead-slurm-variables-reference.html)  | 
| \$1SLURM\$1DB\$1SECRET\$1ARN |  [\[See the AWS documentation website for more details\]](http://docs.amazonaws.cn/en_us/sagemaker/latest/dg/sagemaker-hyperpod-multihead-slurm-variables-reference.html)  | 
| \$1SLURM\$1EXECUTION\$1ROLE\$1ARN |  [\[See the AWS documentation website for more details\]](http://docs.amazonaws.cn/en_us/sagemaker/latest/dg/sagemaker-hyperpod-multihead-slurm-variables-reference.html)  | 
| \$1SLURM\$1FSX\$1DNS\$1NAME |  [\[See the AWS documentation website for more details\]](http://docs.amazonaws.cn/en_us/sagemaker/latest/dg/sagemaker-hyperpod-multihead-slurm-variables-reference.html)  | 
| \$1SLURM\$1FSX\$1MOUNT\$1NAME |  [\[See the AWS documentation website for more details\]](http://docs.amazonaws.cn/en_us/sagemaker/latest/dg/sagemaker-hyperpod-multihead-slurm-variables-reference.html)  | 
| \$1SLURM\$1SNS\$1FAILOVER\$1TOPIC\$1ARN |  [\[See the AWS documentation website for more details\]](http://docs.amazonaws.cn/en_us/sagemaker/latest/dg/sagemaker-hyperpod-multihead-slurm-variables-reference.html)  |