Writing Queue Adapters

FireWorks is intended to support multiple queueing systems. To support a new queueing system, a few functions need to be defined for that queue manager (e.g., what command is used to submit jobs?). In most cases, new queue managers can be supported with minimal effort.

Modifying the template of the CommonAdapter

The FireWorks CommonAdapter supports several queueing engines such as PBS, SGE, SLURM, and IBM LoadLeveler. If you want to use one of these queueing systems but make minor modifications to how the queue submission file looks, you only need to write a new template file and point your queue adapter to it.

  1. Create a template file for job submission. Variables that you want to specify later should be written using the $${var} notation. Save this template file somewhere, e.g. as PBS_template_custom.txt. An example template file is given below:

    #!/bin/bash
    
    #PBS -l nodes=$${nnodes}:ppn=$${ppnode}
    #PBS -l walltime=$${walltime}
    #PBS -q $${queue}
    #PBS -A $${account}
    #PBS -G $${group_name}
    #PBS -N $${job_name}
    #PBS -o FW_job.out
    #PBS -e FW_job.error
    
    $${pre_rocket}
    cd $${launch_dir}
    $${rocket_launch}
    $${post_rocket}
    
    # CommonAdapter (PBS) completed writing Template
    

    Note

    Be sure to keep the lines involving cd $${launch_dir} and $${rocket_launch} intact. Your template file does not need to have any other variables, although the $${queue} variable helps FireWorks count how many jobs you have in a given queue. Also, not all variable names will need to specified in order to write a queue script, so feel free to add lines containing optional variables at this stage.

  2. Find your Queue Adapter file from the queue tutorial - it should be named my_qadapter.yaml. Modify it so that there is an additional parameter called _fw_template_file that points to your new template file. In addition, add lines to set the values of variables from your template (if you leave a variable in the template undefined, the line containing it will be skipped). For example, your custom my_qadapter.yaml file might look like this:

    _fw_name: CommonAdapter
    _fw_q_type: PBS
    _fw_template_file: /path/to/PBS_template_custom.txt
    rocket_launch: rlaunch -w path/to/my_fworker.yaml -l path/to/my_launchpad.yaml singleshot
    nnodes: 1
    ppnode: 1
    walltime: '00:02:00'
    queue: debug
    account: null
    job_name: null
    logdir: path/to/logging
    pre_rocket: null
    post_rocket: null
    
  3. Use this new my_qadapter.yaml file (with the _fw_template_file key specified) when using the queue launcher. The queue launcher will write scripts according to your custom template, with variables substituted according to your my_qadapter.yaml file.

Writing a new queue adapter

If you need to support a new queueing system, you will change the Python code by either (i) modifying the CommonAdapter or (ii) writing a new qadapter from scratch. In either case, we suggest you contact us for help (see Contributing / Contact / Bug Reports) so that the process is as smooth and painless as possible.

Modifying the CommonAdapter

The CommonAdapter, which supports several queueing systems, is located in <INSTALL_DIR>/fireworks/user_objects/queue_adapters/common_adapter.py (you can find out <INSTALL_DIR by typing lpad version). Review the code and make changes as necessary for your queue type to commonadapter.py.

Note that you can make basic changes to the submit commands (e.g., qstat or squeue) by overriding the q_commands_override in your qadapter YAML file:

_q_commands_override:
    submit_cmd: my_qsubmit
    status_cmd: my_qstatus

If you decide that modifications to the CommonAdapter are necessary, make sure to:

  • Add your queue type to supported_q_types
  • Ensure the submit_cmd parameter is set correctly
  • Add a default template file for your queue in the same directory as common_adapter.py, e.g. QUEUETYPE_template.txt. Some examples are present in the FireWorks codebase.
  • Review the remaining methods for consistency with your queue, e.g. get_njobs_in_queue and get_status_cmd.

If all methods are implemented correctly, your new adapter should be functional and you can use it by modifying my_launchapd.yaml:

  • Set the _fw_name to CommonAdapter
  • Set the _fw_q_type` to your new queue type

Writing a new adapter from scratch

If your queue is a complex entity that is different than typical queue managers (maybe a web-based submission framework), you’ll need to write a new class from scratch that extends QueueAdapterBase and:

  • implement the submit_to_queue() method
  • implement the get_njobs_in_queue() method
  • set the _fw_name parameter to some unique String.
  • set the template_file variable to a template file for your queue scripts
  • implement the get_script_str() method (only in rare instances where your queue submission doesn’t involve writing a templated script, otherwise do not implement this method)

You might look at the CommonAdapter class or PBSAdapterNEWT for examples. After writing your new code, decide on a location for your queue adapter Python code and template file. The built-in queue adapters are located in <INSTALL_DIR>/fireworks/user_objects/queue_adapters, and FireWorks will discover your code there automatically (you can find out <INSTALL_DIR> by typing lpad version). However, you can also place your queue adapter in a different Python package if you set the ADD_USER_PACKAGES option as in the FW config.

Again, we suggest that you contact us for help (see Contributing / Contact / Bug Reports) if you run into any problems during the process.