# SETUP (common to all tutorials)
import fermioniq
client = fermioniq.Client() # Initialize the client (assumes environment variables are set)

import rich # Module for pretty printing
import nest_asyncio # Necessary only for Jupyter, can be omitted in .py files
nest_asyncio.apply()

9) Asynchronous jobs

Sometimes it is not desirable for the program to block and wait for the emulation to finish, especially for larger jobs. It is possible to submit a job and then continue with program execution, and later on retrieve the results of the job.

Let’s create a qiskit circuit as usual.

from qiskit import QuantumCircuit

def qiskit_bell_pair():
    circuit = QuantumCircuit(2)
    circuit.h(0)
    circuit.cx(0, 1)
    return circuit

circuit = qiskit_bell_pair()

# Create an emulator job
emulator_job = fermioniq.EmulatorJob(circuit=circuit)

We can schedule an asynchronous job using the schedule_async() method of the client.

# Asynchronously schedule the job
job = client.schedule_async(emulator_job)

# Print the job ID and status
print(f"Job id {job.id}. Status {job.status_code}: {job.status}.")

At any time we can block and wait for the emulation to finish, and optionally recieve live updates on the progress. This can be done using the subscribe_to_events() method of the client.

# Block and wait for a job to finish. Here we pass the job id to the subscribe_to_events( ) method
client.subscribe_to_events(job.id, log_updates=True)

Alternatively, we can check whether the job has finished at a later time. If it has, we can retrieve the results.

status = client.get_status(job.id)

if status == 'finished':
    # Retrieve and print results
    rich.print(client.get_results(job.id))

If you lose the job ID or just want to view the status of your jobs, you can list them using the jobs() method of the client. Printing the jobs object with rich.print renders a table. To get the jobs as a list, use the job_list attribute.

# Limit: (maximum) N=number of jobs to retrieve
# Offset: From which point to list jobs (leave at 0 to list the most recent jobs)
jobs = client.jobs(limit=10, offset=0)
rich.print(jobs)

# Print the results of the most recent job
last_result = client.get_results(jobs.job_list[0].id)
rich.print(last_result)

Finally, it is possible to cancel a job by using the cancel() method of the client.

# Schedule a job and immediately cancel it
job = client.schedule_async(emulator_job)
client.cancel(job.id)