Remove channel strategy & q-ctrl (#1966)

* Remove channel strategy & q-ctrl

* Add release note

* merge conflicts again

* Address comments

Author: kt474

.github/workflows/q-ctrl-tests.yml

@@ -42,7 +42,6 @@ def __init__(
         instance: Optional[str] = None,
         proxies: Optional[ProxyConfiguration] = None,
         verify: Optional[bool] = True,
-        channel_strategy: Optional[str] = None,
     ):
         """Account constructor.
 
@@ -53,15 +52,13 @@ def __init__(
             instance: Service instance to use.
             proxies: Proxy configuration.
             verify: Whether to verify server's TLS certificate.
-            channel_strategy: Error mitigation strategy.
         """
         self.channel: str = None
         self.url: str = None
         self.token = token
         self.instance = instance
         self.proxies = proxies
         self.verify = verify
-        self.channel_strategy = channel_strategy
         self.private_endpoint: bool = False
 
     def to_saved_format(self) -> dict:
@@ -81,7 +78,6 @@ def from_saved_format(cls, data: dict) -> "Account":
         token = data.get("token")
         instance = data.get("instance")
         verify = data.get("verify", True)
-        channel_strategy = data.get("channel_strategy")
         private_endpoint = data.get("private_endpoint", False)
         return cls.create_account(
             channel=channel,
@@ -90,7 +86,6 @@ def from_saved_format(cls, data: dict) -> "Account":
             instance=instance,
             proxies=proxies,
             verify=verify,
-            channel_strategy=channel_strategy,
             private_endpoint=private_endpoint,
         )
 
@@ -103,7 +98,6 @@ def create_account(
         instance: Optional[str] = None,
         proxies: Optional[ProxyConfiguration] = None,
         verify: Optional[bool] = True,
-        channel_strategy: Optional[str] = None,
         private_endpoint: Optional[bool] = False,
     ) -> "Account":
         """Creates an account for a specific channel."""
@@ -114,7 +108,6 @@ def create_account(
                 instance=instance,
                 proxies=proxies,
                 verify=verify,
-                channel_strategy=channel_strategy,
             )
         elif channel == "ibm_cloud":
             return CloudAccount(
@@ -123,7 +116,6 @@ def create_account(
                 instance=instance,
                 proxies=proxies,
                 verify=verify,
-                channel_strategy=channel_strategy,
                 private_endpoint=private_endpoint,
             )
         else:
@@ -167,20 +159,8 @@ def validate(self) -> "Account":
         self._assert_valid_url(self.url)
         self._assert_valid_instance(self.instance)
         self._assert_valid_proxies(self.proxies)
-        self._assert_valid_channel_strategy(self.channel_strategy)
         return self
 
-    @staticmethod
-    def _assert_valid_channel_strategy(channel_strategy: str) -> None:
-        """Assert that the channel strategy is valid."""
-        # add more strategies as they are implemented
-        strategies = ["q-ctrl", "default"]
-        if channel_strategy and channel_strategy not in strategies:
-            raise InvalidAccountError(
-                f"Invalid `channel_strategy` value. Expected one of "
-                f"{strategies}, got '{channel_strategy}'."
-            )
-
     @staticmethod
     def _assert_valid_channel(channel: ChannelType) -> None:
         """Assert that the channel parameter is valid."""
@@ -229,7 +209,6 @@ def __init__(
         instance: Optional[str] = None,
         proxies: Optional[ProxyConfiguration] = None,
         verify: Optional[bool] = True,
-        channel_strategy: Optional[str] = None,
     ):
         """Account constructor.
 
@@ -239,9 +218,8 @@ def __init__(
             instance: Service instance to use.
             proxies: Proxy configuration.
             verify: Whether to verify server's TLS certificate.
-            channel_strategy: Error mitigation strategy.
         """
-        super().__init__(token, instance, proxies, verify, channel_strategy)
+        super().__init__(token, instance, proxies, verify)
         resolved_url = url or IBM_QUANTUM_API_URL
         self.channel = "ibm_quantum"
         self.url = resolved_url
@@ -272,7 +250,6 @@ def __init__(
         instance: Optional[str] = None,
         proxies: Optional[ProxyConfiguration] = None,
         verify: Optional[bool] = True,
-        channel_strategy: Optional[str] = None,
         private_endpoint: Optional[bool] = False,
     ):
         """Account constructor.
@@ -283,10 +260,9 @@ def __init__(
             instance: Service instance to use.
             proxies: Proxy configuration.
             verify: Whether to verify server's TLS certificate.
-            channel_strategy: Error mitigation strategy.
             private_endpoint: Connect to private API URL.
         """
-        super().__init__(token, instance, proxies, verify, channel_strategy)
+        super().__init__(token, instance, proxies, verify)
         resolved_url = url or IBM_CLOUD_API_URL
         self.channel = "ibm_cloud"
         self.url = resolved_url

qiskit_ibm_runtime/accounts/account.py

@@ -45,7 +45,6 @@ def save(
         proxies: Optional[ProxyConfiguration] = None,
         verify: Optional[bool] = None,
         overwrite: Optional[bool] = False,
-        channel_strategy: Optional[str] = None,
         set_as_default: Optional[bool] = None,
         private_endpoint: Optional[bool] = False,
     ) -> None:
@@ -61,7 +60,6 @@ def save(
             instance=instance,
             proxies=proxies,
             verify=verify,
-            channel_strategy=channel_strategy,
             private_endpoint=private_endpoint,
         )
         return save_config(

qiskit_ibm_runtime/accounts/management.py

@@ -61,7 +61,6 @@ def program_run(
         start_session: Optional[bool] = False,
         session_time: Optional[int] = None,
         private: Optional[bool] = False,
-        channel_strategy: Optional[str] = None,
     ) -> Dict:
         """Run the specified program.
 
@@ -78,7 +77,6 @@ def program_run(
             start_session: Set to True to explicitly start a runtime session. Defaults to False.
             session_time: Length of session in seconds.
             private: Marks job as private.
-            channel_strategy: Error mitigation strategy.
 
         Returns:
             JSON response.
@@ -99,7 +97,6 @@ def program_run(
             start_session=start_session,
             session_time=session_time,
             private=private,
-            channel_strategy=channel_strategy,
             **hgp_dict,
         )
 
@@ -274,27 +271,17 @@ def session_details(self, session_id: str) -> Dict[str, Any]:
         """
         return self._api.runtime_session(session_id=session_id).details()
 
-    def list_backends(
-        self, hgp: Optional[str] = None, channel_strategy: Optional[str] = None
-    ) -> List[str]:
+    def list_backends(self, hgp: Optional[str] = None) -> List[str]:
         """Return IBM backends available for this service instance.
 
         Args:
             hgp: Filter by hub/group/project.
-            channel_strategy: Filter by channel strategy.
 
         Returns:
             IBM backends available for this service instance.
         """
-        return self._api.backends(hgp=hgp, channel_strategy=channel_strategy)["devices"]
 
-    def is_qctrl_enabled(self) -> bool:
-        """Returns a boolean of whether or not the instance has q-ctrl enabled.
-
-        Returns:
-            Boolean value.
-        """
-        return self._api.is_qctrl_enabled()
+        return self._api.backends(hgp=hgp)["devices"]
 
     def backend_configuration(self, backend_name: str) -> Dict[str, Any]:
         """Return the configuration of the IBM backend.

qiskit_ibm_runtime/api/clients/runtime.py

@@ -77,7 +77,6 @@ def program_run(
         start_session: Optional[bool] = False,
         session_time: Optional[int] = None,
         private: Optional[bool] = False,
-        channel_strategy: Optional[str] = None,
     ) -> Dict:
         """Execute the program.
 
@@ -96,7 +95,6 @@ def program_run(
             start_session: Set to True to explicitly start a runtime session. Defaults to False.
             session_time: Length of session in seconds.
             private: Marks job as private.
-            channel_strategy: Error mitigation strategy.
 
         Returns:
             JSON response.
@@ -125,8 +123,6 @@ def program_run(
             payload["hub"] = hub
             payload["group"] = group
             payload["project"] = project
-        if channel_strategy:
-            payload["channel_strategy"] = channel_strategy
         if private:
             payload["private"] = True
         data = json.dumps(payload, cls=RuntimeEncoder)
@@ -216,14 +212,12 @@ def backends(
         self,
         hgp: Optional[str] = None,
         timeout: Optional[float] = None,
-        channel_strategy: Optional[str] = None,
     ) -> Dict[str, List[str]]:
         """Return a list of IBM backends.
 
         Args:
             hgp: The service instance to use, only for ``ibm_quantum`` channel, in h/g/p format.
             timeout: Number of seconds to wait for the request.
-            channel_strategy: Error mitigation strategy.
 
         Returns:
             JSON response.
@@ -232,19 +226,8 @@ def backends(
         params = {}
         if hgp:
             params["provider"] = hgp
-        if channel_strategy:
-            params["channel_strategy"] = channel_strategy
         return self.session.get(url, params=params, timeout=timeout).json()
 
-    def is_qctrl_enabled(self) -> bool:
-        """Return boolean of whether or not the instance has q-ctrl enabled.
-
-        Returns:
-            Boolean value.
-        """
-        url = self.get_url("cloud_instance")
-        return self.session.get(url).json().get("qctrl_enabled")
-
     def usage(self) -> Dict[str, Any]:
         """Return monthly open plan usage information.
 

qiskit_ibm_runtime/api/rest/runtime.py

@@ -27,7 +27,6 @@
 from .options.estimator_options import EstimatorOptions
 from .base_primitive import BasePrimitiveV2
 from .utils.deprecation import issue_deprecation_msg
-from .utils.qctrl import validate_v2 as qctrl_validate_v2
 from .utils import validate_estimator_pubs
 
 # pylint: disable=unused-import,cyclic-import
@@ -119,8 +118,6 @@ def __init__(
 
             options: Estimator options, see :class:`EstimatorOptions` for detailed description.
 
-        Raises:
-            NotImplementedError: If "q-ctrl" channel strategy is used.
         """
         BaseEstimatorV2.__init__(self)
         Estimator.__init__(self)
@@ -167,10 +164,6 @@ def _validate_options(self, options: dict) -> None:
             ValueError: if validation fails.
         """
 
-        if self._service._channel_strategy == "q-ctrl":
-            qctrl_validate_v2(options)
-            return
-
         if (
             options.get("resilience", {}).get("pec_mitigation", False) is True
             and self._backend is not None

qiskit_ibm_runtime/estimator.py

@@ -49,7 +49,6 @@ def __init__(self) -> None:
             An instance of QiskitRuntimeService.
 
         """
-        self._channel_strategy = None
 
     def backend(
         self, name: str = None, instance: str = None  # pylint: disable=unused-argument