Raise exception when number of circuits exceeds maximum circuits allowed on backendkend max_circuits

qiskit_ibm_runtime/base_primitive.py

@@ -21,6 +21,7 @@
 
 from qiskit.providers.options import Options as TerraOptions
 
+from qiskit_ibm_runtime.exceptions import IBMInputValueError
 from .options import Options
 from .options.utils import set_default_error_levels
 from .runtime_job import RuntimeJob
@@ -136,7 +137,6 @@ def __init__(
                 raise ValueError(
                     "A backend or session must be specified when not using ibm_cloud channel."
                 )
-
         # self._first_run = True
         # self._circuits_map = {}
         # if self.circuits:
@@ -174,8 +174,19 @@ def _run_primitive(self, primitive_inputs: Dict, user_kwargs: Dict) -> RuntimeJo
         self._validate_options(combined)
         primitive_inputs.update(Options._get_program_inputs(combined))
 
+        circuits = primitive_inputs["circuits"]
+        if (
+            self._backend
+            and isinstance(self._backend, IBMBackend)
+            and len(circuits) > self._backend.max_circuits
+        ):
+            raise IBMInputValueError(
+                f"Number of circuits, {len(circuits)} exceeds the "
+                f"maximum for this backend, {self._backend.max_circuits})"
+            )
+
         if self._backend and combined["transpilation"]["skip_transpilation"]:
-            for circ in primitive_inputs["circuits"]:
+            for circ in circuits:
                 self._backend.check_faulty(circ)
 
         logger.info("Submitting job using options %s", combined)

releasenotes/notes/max_circuits-b773c860f8df1cf4.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    Raise an exception if the number of circuits passed to BasePrimitive._run_primitive()
+    exceeds the number of circuits supported on the backend. 
+

test/unit/test_ibm_primitives.py

@@ -40,6 +40,7 @@
 from qiskit_ibm_runtime.ibm_backend import IBMBackend
 import qiskit_ibm_runtime.session as session_pkg
 from qiskit_ibm_runtime.utils.utils import _hash
+from qiskit_ibm_runtime.exceptions import IBMInputValueError
 
 from ..ibm_test_case import IBMTestCase
 from ..utils import (
@@ -190,7 +191,10 @@ def test_init_with_backend_instance(self):
         """Test initializing a primitive with a backend instance."""
         primitives = [Sampler, Estimator]
         service = MagicMock()
-        backend = IBMBackend(configuration=MagicMock(), service=service, api_client=MagicMock())
+        model_backend = FakeManila()
+        backend = IBMBackend(
+            configuration=model_backend.configuration(), service=service, api_client=MagicMock()
+        )
         backend.name = "ibm_gotham"
 
         for cls in primitives:
@@ -266,12 +270,14 @@ def test_default_session_cm_new_backend(self):
         """Test using a different backend within context manager."""
         cm_backend = "ibm_metropolis"
         primitives = [Sampler, Estimator]
-
+        model_backend = FakeManila()
         for cls in primitives:
             with self.subTest(primitive=cls):
                 service = MagicMock()
                 backend = IBMBackend(
-                    configuration=MagicMock(), service=service, api_client=MagicMock()
+                    configuration=model_backend.configuration(),
+                    service=service,
+                    api_client=MagicMock(),
                 )
                 backend.name = "ibm_gotham"
 
@@ -286,12 +292,14 @@ def test_default_session_cm_new_backend(self):
     def test_no_session(self):
         """Test running without session."""
         primitives = [Sampler, Estimator]
-
+        model_backend = FakeManila()
         for cls in primitives:
             with self.subTest(primitive=cls):
                 service = MagicMock()
                 backend = IBMBackend(
-                    configuration=MagicMock(), service=service, api_client=MagicMock()
+                    configuration=model_backend.configuration(),
+                    service=service,
+                    api_client=MagicMock(),
                 )
                 inst = cls(backend)
                 inst.run(self.qx, observables=self.obs)
@@ -945,3 +953,29 @@ def _assert_dict_partially_equal(self, dict1, dict2):
             dict_paritally_equal(dict1, dict2),
             f"{dict1} and {dict2} not partially equal.",
         )
+
+    def test_too_many_circuits(self):
+        """Test exception when number of circuits exceeds backend._max_circuits"""
+        model_backend = FakeManila()
+        backend = IBMBackend(
+            configuration=model_backend.configuration(),
+            service=MagicMock(),
+            api_client=None,
+            instance=None,
+        )
+        primitives = [Sampler, Estimator]
+        max_circs = backend.configuration().max_experiments
+        circs = []
+        observables = []
+        for _ in range(max_circs + 1):
+            circs.append(self.qx)
+            observables.append(self.obs)
+        for cls in primitives:
+            with self.subTest(primitive=cls):
+                inst = cls(backend=backend)
+                with self.assertRaises(IBMInputValueError) as err:
+                    inst.run(circs, observables=observables)
+        self.assertIn(
+            f"Number of circuits, {max_circs + 1} exceeds the maximum for this backend, {max_circs}",
+            str(err.exception),
+        )