This section gives an overview of the steps involved in using ecFlow.
Step 1: Write a suite definition
The suite definition describes how your tasks run and interact. tasks can be grouped together in families, which themselves may be placed in other families and/or suites. All the entities (tasks, families and suites) are called nodes and form a hierarchical tree.
There are two main methods for describing a suite definition to the ecflow_server.
via a text suite definition
The grammar of this text definition is described by Definition file Grammar. This grammar does not support conditional statements (such as if, while, for) nor the ability to define functions. However, the text definition file can be generated/created using any language which in itself supports conditional statements. The text definition is similar to that offered by SMS/CDP and as such may be an appropriate migration path for some users.
via a Python suite definition
This allows more checking and functionality and as such is our preferred method. See ecFlow Python Api.
Step 2: Write your task scripts
ecf scripts are text files that correspond to the task in the suite definition. The script defines the main work that is to be carried out. The script includes child commands, special comments, and manual sections that provide information for users.
The child commands are a restricted set of ecflow_client commands that communicate with the ecflow_server. They inform the server when the job has started, completed, aborted, or set some event.
Step 3: Start an ecFlow server
After ecflow_server is started, the suite definition can then be loaded into it.
- The user then initiates scheduling in the ecflow_server
- scheduling will check dependencies in the suite definition every minute (by default). If these dependencies are free, the server will submit the task. This process is called job creation. The running process corresponding to the task is referred to as a job.
The running jobs will communicate back to the server using child commands. These cause:
Step 4: Interact with the GUI
ecFlow has a specialised GUI client, called ecflow_ui This is used to visualise and monitor:
- The hierarchical structure of the suite definition. (suite, family, task)
- State changes in the nodes and servers.
- Attributes of the nodes and any dependencies.
- ecf script file and the expanded job file.
In addition, ecflow_ui provides a rich set of ecflow_client commands that can interact with the server.