Amazon Batch job environment variables - Amazon Batch
Services or capabilities described in Amazon Web Services documentation might vary by Region. To see the differences applicable to the China Regions, see Getting Started with Amazon Web Services in China.

Amazon Batch job environment variables

Amazon Batch automatically sets specific environment variables in container jobs. These environment variables provide introspection for the containers inside jobs, and you can use the values of these variables in the logic of your applications. All variables that are set by Amazon Batch begin with the prefix, AWS_BATCH_. This is a protected environment variable prefix, and you can't use this prefix for your own variables in job definitions or overrides.

The following environment variables are available in job containers:

AWS_BATCH_CE_NAME

This variable is set to the name of the compute environment where your job is placed.

AWS_BATCH_JOB_ARRAY_INDEX

This variable is only set in child array jobs. The array job index begins at 0, and each child job receives a unique index number. For example, an array job with 10 children has index values of 0-9. You can use this index value to control how your array job children are differentiated. For more information, see Tutorial: Using the array job index to control job differentiation.

AWS_BATCH_JOB_ATTEMPT

This variable is set to the job attempt number. The first attempt is numbered 1. For more information, see Automated job retries.

AWS_BATCH_JOB_ID

This variable is set to the Amazon Batch job ID.

AWS_BATCH_JOB_MAIN_NODE_INDEX

This variable is only set in multi-node parallel jobs. This variable is set to the index number of the job's main node. Your application code can compare the AWS_BATCH_JOB_MAIN_NODE_INDEX to the AWS_BATCH_JOB_NODE_INDEX on an individual node to determine if it's the main node.

AWS_BATCH_JOB_MAIN_NODE_PRIVATE_IPV4_ADDRESS

This variable is only set in multi-node parallel job child nodes (it isn't present on the main node). This variable is set to the private IPv4 address of the job's main node. Your child node's application code can use this address to communicate with the main node.

AWS_BATCH_JOB_NODE_INDEX

This variable is only set in multi-node parallel jobs. This variable is set to the node index number of the node. The node index begins at 0, and each node receives a unique index number. For example, a multi-node parallel job with 10 children has index values of 0-9.

AWS_BATCH_JOB_NUM_NODES

This variable is only set in multi-node parallel jobs. This variable is set to the number of nodes that you have requested for your multi-node parallel job.

AWS_BATCH_JQ_NAME

This variable is set to the name of the job queue to which your job was submitted.