1. Variables for task programs
Batch Compute provides the following variables for task programs:
| Variable | Value |
|---|---|
| BATCH_COMPUTE_DAG_JOB_ID | Job ID, depending on the actual situation |
| BATCH_COMPUTE_DAG_TASK_ID | Task ID, depending on the actual situation |
| BATCH_COMPUTE_DAG_INSTANCE_ID | Instance ID, depending on the actual situation |
| BATCH_COMPUTE_OSS_HOST | OSS host name, depending on the actual situation |
| BATCH_COMPUTE_REGION | Region where the host is located, depending on the actual situation |
| BATCH_COMPUTE_CLUSTER_ID | cluster id |
| BATCH_COMPUTE_WORKER_ID | worker id |
See the following table for the difference of variables for task programs running in a Docker container:
| Variable | Value |
|---|---|
| USER | root |
| PWD | /batchcompute/workdir |
| PATH | /sbin:/usr/sbin:/bin:/usr/bin. Note that the path /usr/local/bin does not exist. If you want to set a path, specify it in the EnvVars field when submitting the job. |
| HOME | /root |
| BATCH_COMPUTE_DAG_JOB_ID | Job ID, depending on the actual situation |
| BATCH_COMPUTE_DAG_TASK_ID | Task ID, depending on the actual situation |
| BATCH_COMPUTE_DAG_INSTANCE_ID | Instance ID, depending on the actual situation |
| BATCH_COMPUTE_OSS_HOST | OSS host name, depending on the actual situation |
| BATCH_COMPUTE_REGION | Region where the host is located, depending on the actual situation |
2. How to use variables
You can obtain variables from EnvVars in task programs, for example:
2.1. Use variables in a Python program:
task_id = os.environ['BATCH_COMPUTE_DAG_TASK_ID']instance_id = os.environ['BATCH_COMPUTE_DAG_INSTANCE_ID']
2.2. Use variables in a Java program:
String taskId = System.getenv("BATCH_COMPUTE_DAG_TASK_ID");String instanceId = System.getenv("BATCH_COMPUTE_DAG_INSTANCE_ID");
3. Define variables
In addition to variables provided by the system, you can also define new variables when submitting a job.
3.1. Use Python SDK
Code snippet:
env = {'k1': 'v1','k2': 'v2'}...job_desc['DAG']['Tasks']['my-task']['Parameters']['Command']['EnvVars']=env...
3.2. Use Java SDK
Code snippet:
Command cmd= new Command();cmd.addEnvVars("k1","v1");cmd.addEnvVars("k2","v2");...TaskDescription desc = TaskDescription();Parameters parmas = new Parameters();params.setCommand(cmd);...desc.setParameters(params);
3.3. Use command line tool
bcs sub "python main.py" -e k1:v1,k2:v2