Installation

To install the Girder Worker on your system, we recommend using pip to install the package. (If you wish to install from source, see the Installing from source section of the developer documentation.)

First, install required system packages:

# Command for Ubuntu
sudo apt-get install libjpeg-dev zlib1g-dev libssl-dev

Next, the following command will install the core dependencies:

pip install girder-worker

That will install the core girder-worker library, but not the third-party dependencies for any of its plugins. If you want to enable a set of plugins, their IDs should be included as extras to the pip install command. For instance, if you are planning to use the R plugin and the spark plugin, you would run:

pip install girder-worker[r,spark]

You can run this command at any time to install dependencies of other plugins, even if the girder worker is already installed.

Remote Execution

Want to run things remotely? Girder worker relies on celery as its distributed task queue. Celery requires a message broker, which can be Mongo, though Celery recommends using RabbitMQ as your message broker.

If you have followed the standard or development installation process, celery will have already been installed.

Run the girder_worker, which will run a celery worker process:

girder-worker

On the client, run a script akin to the following example:

python examples/example_client.py

Configuration

Several aspects of the worker’s behavior are controlled via its configuration file. The easiest way to manage configuration is using the girder-worker-config command that is installed with the package. After installation, run

$ girder-worker-config --help

You should see the list of available sub-commands for reading and writing config values. To show all configuration options, run

$ girder-worker-config list

To set a specific option, use

$ girder-worker-config set <section_name> <option_name> <value>

For example:

$ girder-worker-config set celery broker amqp://me@localhost/

To change a setting back to its default value, use the rm subcommand

$ girder-worker-config rm celery broker

The core configuration parameters are outlined below.

  • celery.app_main: The name of the celery application. Clients will need to use this same name to identify what app to send tasks to. It is recommended to call this “girder_worker” unless you have a reason not to.
  • celery.broker: This is the broker that celery will connect to in order to listen for new tasks. Celery recommends using RabbitMQ as your message broker.
  • girder_worker.tmp_root: Each task is given a temporary directory that it can use if it needs filesystem storage. This config setting points to the root directory under which these temporary directories will be created.
  • girder_worker.plugins_enabled: This is a comma-separated list of plugin IDs that will be enabled at runtime, e.g. spark,vtk.
  • girder_worker.plugin_load_path: If you have any external plugins that are not inside the girder_worker/plugins package directory, set this value to a colon-separated list of directories to search for external plugins that need to be loaded.

Note

After making changes to values in the config file, you will need to restart the worker before the changes will be reflected.