Selection of instances in the new IBM Quantum Platform

[francabrera]

What is the expected feature or enhancement?

Unlike with the ibm_quantum channel, the ibm_cloud channel makes it mandatory to specify an instance when saving an account and it does not provide a way to switch to a different instance other than saving multiple accounts and iterating over them.

Users may have access to more than one Qiskit Runtime service instance in IBM Cloud within their Account, and may want to, instead of specifying a single instance, being able to find the one which has access to a QPU backend or submit workloads to more than one instance within their code.

We would like to allow users in the new IBM Quantum Platform to connect to their accounts within Qiskit and being able to save a default instance or let the provider find the instance within the account which has access to a particular QPU, with the user optionally specifying their plans preferences when looking for an instance, or if they want only to look in one particular region and not the two regions our services are deployed in.

Acceptance criteria

• There is a new channel ibm_quantum_platform which becomes the default channel and deprecates the ibm_quantum and ibm_cloud channels.
• When saving the account with this new channel:
  • The user can optionally specify the default_instance they want to use (by providing a CRN or the Name of the instance).
  • The user can optionally define the region they want to use (us-east, eu-de), defaulting to all regions.
  • The user can optionally define the plans preference order for the provider to select the first instance which access to a particular backend.
• The user can get a backend to run within the account and, if no default instance has been provided for the account, the provider will look for instances in the regions the user wanted to connect to with access to this backend in the plan preference order.
• The user can get a backend to run within the account providing a specific instance CRN or Name.

Example:

from qiskit_ibm_runtime import QiskitRuntimeService
service = QiskitRuntimeService.save_account(
    # No channel needs to be specified, ibm_quantum_platform is the default
    token=token,
    default_instance="CRN/NAME", #Optional
    region="us-east|eu-de", # Optional
    plans_preference=['Open',...], #Optional
    set_as_default=True  #Optional
)

service = QiskitRuntimeService()

backend = service.backend('ibm_aachen') # valid, selects and instance which access to this backend
backend = service.backend('ibm_aachen', instance="CRN/NAME") # also valid, uses the instance specified by the user

cc @jyu00

[jyu00]

The user can get a backend to run within the account and, if no default instance has been provided for the account, the provider will look for instances in the regions the user wanted to connect to with access to this backend in the plan preference order.

What happens if one specifies a default_instance in save_account(), but that instance doesn't have access to the backend they specify in service.backend()? Does it fail or pick a different instance?

[francabrera]

What happens if one specifies a default_instance in save_account(), but that instance doesn't have access to the backend they specify in service.backend()? Does it fail or pick a different instance?

it should fail

[jyu00]

@beckykd we're going to need doc update for this when it's done. It my not be obvious to users where to find their instance names and plans.

[kt474]

the provider will look for instances in the regions the user wanted to connect to with access to this backend in the plan preference order.

Does this mean looking at other instances the user has saved? Or somehow fetching all the instances the user has access to?

[francabrera]

the provider will look for instances in the regions the user wanted to connect to with access to this backend in the plan preference order.

Does this mean looking at other instances the user has saved? Or somehow fetching all the instances the user has access to?

Fetching from the IBM Cloud platform API