Jobdefs

Jobdefs, short for job definitions, are templates used by batch processing systems and workflow engines to describe how a task should be executed. A job definition encapsulates the executable, inputs, environment, resources, and behavior required to run a job, allowing operators to submit many jobs without redefining these details each time.

Typically a job definition specifies the command or entry point, arguments, working directory, and the environment variables. It also lists resource requirements such as CPU, memory, and, where applicable, GPUs. It may include data and volume mounts, network configuration, and logging settings. Behavioral options include retry policies, timeouts, and dependencies on other jobs.

Job definitions may be parameterized to allow multiple runs with different inputs. They are versioned and stored in a registry; new revisions can be created while preserving older ones for reproducibility. Submitting a job references a specific job definition, enabling consistent, traceable execution across environments.

In cloud batch services such as AWS Batch, a job definition defines the container image, resource needs, and execution environment; in other contexts, similar templates exist but may use different terminology. The concept is common across batch processing, data pipelines, and high-performance computing workflows as a means to standardize and reuse run configurations.