FAQ

How Long Will the History Data be Stored?

By default, the execution history data is retained for 30 days. However, you can customize this setting by modifying the histRetentionDays field in a YAML file.

How to Use Specific Host and Port or blackdagger server?

To configure the host and port for blackdagger server, you can set the environment variables BLACKDAGGER_HOST and BLACKDAGGER_PORT. Refer to the Configuration Options for more details.

How to Specify the DAGs Directory for blackdagger server and blackdagger scheduler?

You can customize the directory used to store DAG files by setting the environment variable BLACKDAGGER_DAGS. See Configuration Options for more information.

How Can I Retry a DAG from a Specific Task?

If you want to retry a DAG from a specific task, you can set the status of that task to failed by clicking the step in the Web UI. When you rerun the DAG, it will execute the failed task and any subsequent tasks.

Can I Use Symlinked DAG Files and Still Edit SPEC in the Web UI?

Yes. Blackdagger supports DAG files that are symlinked and can also work when the configured DAG directory is a symlink.

If SPEC cannot be shown or saved:

  • Ensure the process user has read and write permissions for the symlink

    target files.

  • Ensure files use .yaml or .yml extensions.

  • As a fallback, set BLACKDAGGER_DAGS to the real target directory path

    instead of the symlink path.

Can I Run the Same DAG in Parallel with Different Parameters?

Not natively in the current runtime. A DAG is guarded by a single local socket, so only one active run of the same DAG is allowed at a time.

Workarounds:

  • Use separate DAG files for each parameter set.

  • Use one orchestrator DAG that fans out work in parallel inside a step

    (for example with xargs -P or GNU parallel).

How Does It Track Running Processes Without DBMS?

blackdagger uses Unix sockets to communicate with running processes.