Condor-G and DAGman

Condor-G is a client tool that can manage the execution of a set of related tasks on Grid-accessible computation resources. Condor-G allows the user to specify a set of tasks to be run and any relationships or dependencies between tasks. It then goes about executing the tasks using available resources. Condor-G provides a very nice client interface to the Condor and GRAM computation services.

DAGman is a related tool that allows users to specify a directed acyclic graph (DAG) of tasks to be executed with (potentially) complex relationships and dependencies. DAGman optimizes the ordering of task execution and works with Condor-G to execute the tasks in an optimal sequence using available Grid compute resources. The most complicated DAGs are typically produced by computer programs that plan a set of tasks based on high-level user requests. DAGman provides a key element of powerful data processing systems like the Virtual Data System.