Bugfix in ExperimentData's handling of metadata save

qiskit_experiments/framework/experiment_data.py

@@ -29,6 +29,7 @@
 import time
 import io
 import sys
+import json
 import traceback
 import numpy as np
 from dateutil import tz
@@ -1470,7 +1471,7 @@ def _save_experiment_metadata(self, suppress_errors: bool = True) -> None:
 
             if handle_metadata_separately:
                 self.service.file_upload(
-                    self._db_data.experiment_id, self._metadata_filename, metadata
+                    self._db_data.experiment_id, self._metadata_filename, metadata, json_encoder=self._json_encoder
                 )
                 self._db_data.metadata = metadata
 
@@ -1483,7 +1484,8 @@ def _save_experiment_metadata(self, suppress_errors: bool = True) -> None:
     def _metadata_too_large(self):
         """Determines whether the metadata should be stored in a separate file"""
         # currently the entire POST JSON request body is limited by default to 100kb
-        return sys.getsizeof(self.metadata) > 10000
+        total_metadata_size = sys.getsizeof(json.dumps(self.metadata, cls=self._json_encoder))
+        return total_metadata_size > 10000
 
     def save(
         self,
@@ -2057,7 +2059,7 @@ def load(
             service = cls.get_service_from_provider(provider)
         data = service.experiment(experiment_id, json_decoder=cls._json_decoder)
         if service.experiment_has_file(experiment_id, cls._metadata_filename):
-            metadata = service.file_download(experiment_id, cls._metadata_filename)
+            metadata = service.file_download(experiment_id, cls._metadata_filename, json_decoder=cls._json_decoder)
             data.metadata.update(metadata)
         expdata = cls(service=service, db_data=data, provider=provider)
 

releasenotes/notes/experiment_data_metadata_save_fix-912b7180a28cfb03.yaml

@@ -0,0 +1,4 @@
+---
+fixes:
+  - |
+    Fixed a bug in :class:`.ExperimentData` which caused experiment saves to the cloud service to fail when the metadata is large.

requirements.txt

@@ -3,7 +3,7 @@ numpy>=1.17
 # see https://github.com/cvxpy/cvxpy/issues/2158
 scipy>=1.4,<1.11.0
 qiskit-terra>=0.24
-qiskit-ibm-experiment>=0.3.3
+qiskit-ibm-experiment>=0.3.4
 matplotlib>=3.4
 uncertainties
 lmfit

test/database_service/test_db_experiment_data.py

@@ -1114,3 +1114,14 @@ def test_getters(self):
         metadata = {"_source": "source_data"}
         data._db_data.metadata = metadata
         self.assertEqual(data.source, "source_data")
+
+    def test_metadata_too_large(self):
+        """Tests that ExperimentData can detect when the metadta
+        should be saved as a seperate file"""
+        exp_data = ExperimentData()
+        metadata_size = 100000
+        exp_data.metadata["components"] = [
+            {"physical_qubits": [0], "device_components": [f"Qubit{n}"]}
+            for n in range(metadata_size)
+        ]
+        self.assertTrue(exp_data._metadata_too_large())