qiskit-documentation/docs/migration-guides/qiskit-runtime-from-ibm-pro...

224 lines
5.9 KiB
Plaintext

---
title: Migrate from qiskit-ibm-provider
description: Migrate from backend.run in qiskit-ibm-provider to using Qiskit Runtime primitives
---
# Migrate from `qiskit_ibm_provider`
This topic shows how to migrate code that implemented `IBMBackend.run()`
by using `qiskit_ibm_provider` to use `qiskit_ibm_runtime`.
## Save accounts
Use the updated code to save accounts.
<Tabs>
<TabItem value="updated" label="Runtime primitives">
The new syntax accepts credentials for
Qiskit Runtime on IBM Cloud or IBM Quantum Platform. For more
information on retrieving account credentials, see [Install and set up](/guides/setup-channel).
``` python
from qiskit_ibm_runtime import QiskitRuntimeService
# IBM Quantum channel; set to default
QiskitRuntimeService.save_account(channel="ibm_quantum", token="<IQP_TOKEN>", overwrite=True, set_as_default=True)
```
Additionally, you can now name your saved credentials and load the credentials by name.
``` python
# Save different accounts for open and premium access
QiskitRuntimeService.save_account(channel="ibm_quantum", token="<IQX_TOKEN>", instance="h1/g1/p1", name="premium")
QiskitRuntimeService.save_account(channel="ibm_quantum", token="<IQX_TOKEN>", instance="h2/g2/p2", name="open")
# Load the "open" credentials
service = QiskitRuntimeService(name="open")
```
</TabItem>
<TabItem value="legacy" label="backend.run">
``` python
IBMProvider.save_account(token='MY_API_TOKEN')
```
</TabItem>
</Tabs>
## Load accounts
Use the updated code to load accounts.
<Tabs>
<TabItem value="updated" label="Runtime primitives">
The `channel` input parameter is
optional. If multiple accounts have been saved in one device and no
`channel` is provided, the default is `"ibm_cloud"`.
``` python
# To access saved credentials for the IBM cloud channel
service = QiskitRuntimeService(channel="ibm_cloud")
# To access saved credentials for the IBM quantum channel
service = QiskitRuntimeService(channel="ibm_quantum")
```
</TabItem>
<TabItem value="legacy" label="backend.run">
``` python
provider = IBMProvider()
```
</TabItem>
</Tabs>
## Instance selection (get a provider)
Use the updated code to select a hub, group, and project.
<Tabs>
<TabItem value="updated" label="Runtime primitives">
When using the `ibm_quantum` channel,
the `hub`, `group`, and `project` are specified through the new
`instance` keyword.
``` python
# To access saved credentials for the IBM quantum channel and select an instance
service = QiskitRuntimeService(channel="ibm_quantum", instance="my_hub/my_group/my_project")
```
</TabItem>
<TabItem value="legacy" label="backend.run">
``` python
provider = IBMProvider(instance="my_hub/my_group/my_project")
```
</TabItem>
</Tabs>
## Get a backend
Use the updated code to specify a backend.
<Tabs>
<TabItem value="updated" label="Runtime primitives">
``` python
# You can specify the instance in service.backend() instead of initializing a new service
backend = service.backend("ibm_backend", instance="h1/g1/p1")
```
If you don't know what backend you want to use, you can instead use code such as the following:
```python
from qiskit_ibm_runtime import QiskitRuntimeService
service = QiskitRuntimeService()
backend = service.least_busy(operational=True, simulator=False, min_num_qubits=<num_qubits>)
```
With Qiskit Runtime, you can also run in local testing mode.
```python
# Define a local backend
from qiskit_ibm_runtime.fake_provider import FakeManilaV2
backend = FakeManilaV2()
# You could use an Aer simulator instead by using the following code:
# from qiskit_aer import AerSimulator
# backend = AerSimulator()
```
</TabItem>
<TabItem value="legacy" label="backend.run">
``` python
provider = ibm.get_provider(hub="h1", group="g1", project="p1")
backend = provider.get_backend("ibm_backend")
```
</TabItem>
</Tabs>
## Example: Basic execution
Change the import and run statements, instantiate the primitive, and make sure the input is modified to adhere to the backend's instruction set architecture (ISA).
<Tabs>
<TabItem value="updated" label="Qiskit Runtime">
```python
from qiskit import QuantumCircuit
from qiskit.transpiler.preset_passmanagers import generate_preset_pass_manager
from qiskit_ibm_runtime import QiskitRuntimeService, SamplerV2 as Sampler
service = QiskitRuntimeService()
backend = service.least_busy(operational=True, simulator=False, min_num_qubits=127)
circuit = QuantumCircuit(2, 2)
circuit.h(0)
circuit.cx(0, 1)
circuit.measure_all()
pm = generate_preset_pass_manager(backend=backend, optimization_level=1)
isa_circuit = pm.run(circuit)
sampler = Sampler(backend)
job = sampler.run([isa_circuit])
result = job.result()
print(f" > Counts: {result[0].data.meas.get_counts()}")
```
</TabItem>
<TabItem value="legacy" label="backend.run">
```python
from qiskit_ibm_provider import IBMProvider
from qiskit import QuantumCircuit
from qiskit.compiler import transpile
circuit = QuantumCircuit(2, 2)
circuit.h(0)
circuit.cx(0, 1)
circuit.measure_all()
provider = IBMProvider()
backend = provider.get_backend("ibm_qasm_simulator")
transpiled_circuit = transpile(circuit, backend=backend)
job = backend.run(transpiled_circuit)
print(f" > Counts: {job.result().get_counts()}")
```
</TabItem>
</Tabs>
## Example: Use sessions
<Tabs>
<TabItem value="Updated" label="Runtime primitives">
```python
from qiskit_ibm_runtime import Session
from qiskit_ibm_runtime import QiskitRuntimeService, SamplerV2 as Sampler
with Session(backend=backend) as session:
sampler = Sampler()
job = sampler.run([isa_circuit])
another_job = sampler.run([another_isa_circuit])
result = job.result()
another_result = another_job.result()
```
</TabItem>
<TabItem value="Legacy" label="backend.run">
```python
with backend.open_session() as session:
job = backend.run(transpiled_circuit)
another_job = backend.run(transpiled_circuit)
result = job.result()
another_result = another_job.result()
```
</TabItem>
</Tabs>