Configuring Hosts

In qtoolkit, a Host represents the environment where shell commands are executed. This abstraction allows you to use the same QueueManager and SchedulerIO logic whether you are running commands locally or on a remote cluster.

Available Hosts

LocalHost

The LocalHost executes commands on the same machine where the Python process is running. This is the default host used by the QueueManager.

from qtoolkit.host.local import LocalHost
host = LocalHost()

RemoteHost

The RemoteHost allows you to execute commands on a remote machine, typically via SSH. This is useful when your Python script is running on your workstation, but you need to submit jobs to a cluster.

from qtoolkit.host.remote import RemoteHost, RemoteConfig

config = RemoteConfig(
    host="cluster.example.edu",
    user="myuser",
    root_dir="/home/myuser",
)
host = RemoteHost(config=config)

Host Interface

All host classes implement a common interface, primarily the execute method:

# This is usually called internally by QueueManager
stdout, stderr, exit_code = host.execute("ls -l", workdir="/tmp")

Hosts also provide methods for file manipulation, such as write_text_file, which are used by the QueueManager to upload submission scripts.

Using a Host with QueueManager

When initializing a QueueManager, pass the desired host instance:

from qtoolkit.manager import QueueManager
from qtoolkit.io.slurm import SlurmIO

manager = QueueManager(scheduler_io=SlurmIO(), host=RemoteHost(...))