StashCalculation: throw a warning if the computer node mismatches with the one of source_node (#6862)

We don't raise an error, but a warning. Because there could be a situation that a user's computer will be faulty for whatever reason (migrating transport plugins, etc.). Therefore it should still be possible to stash data from a different computer as long as they share access to the RemoteData path.

Author: khsrali

src/aiida/calculations/stash.py

@@ -9,9 +9,12 @@
 """"""
 
 from aiida import orm
+from aiida.common import AIIDA_LOGGER
 from aiida.common.datastructures import CalcInfo
 from aiida.engine import CalcJob
 
+EXEC_LOGGER = AIIDA_LOGGER.getChild('StashCalculation')
+
 
 class StashCalculation(CalcJob):
     """
@@ -69,6 +72,17 @@ def define(cls, spec):
         }
 
     def prepare_for_submission(self, folder):
+        if self.inputs.source_node.computer.uuid != self.inputs.metadata.computer.uuid:
+            EXEC_LOGGER.warning(
+                'YOUR SETTING MIGHT RESULT IN A SILENT FAILURE!'
+                ' The computer of the source node and the computer of the calculation are strongly advised be the same.'
+                ' However, it is not mandatory,'
+                ' in order to support the case that original computer somehow is not usable, anymore.'
+                ' E.g. the original computer was configured for ``core.torque``, but the HPC has move to SLURM,'
+                ' so you had to create a new computer configured with ``core.slurm``,'
+                " and you'll need a job submission to do this."
+            )
+
         calc_info = CalcInfo()
         calc_info.skip_submit = True
 

tests/calculations/test_stash.py

@@ -50,3 +50,45 @@ def test_stash_calculation_basic(fixture_sandbox, aiida_localhost, generate_calc
     assert calc_info.local_copy_list == []
     assert calc_info.remote_copy_list == []
     assert calc_info.remote_symlink_list == []
+
+
+@pytest.mark.requires_rmq
+def test_stash_calculation_different_computer(
+    fixture_sandbox, aiida_computer_local, generate_calc_job, tmp_path, caplog
+):
+    """Test it emits a warning if the source node is on a different computer."""
+
+    target_base = tmp_path / 'target'
+    source = tmp_path / 'source'
+    source.mkdir()
+
+    a_computer = aiida_computer_local()
+    a_different_computer = aiida_computer_local()
+    assert a_computer.uuid != a_different_computer.uuid
+
+    inputs = {
+        'metadata': {
+            'computer': a_computer,
+            'options': {
+                'resources': {'num_machines': 1},
+                'stash': {
+                    'stash_mode': StashMode.COPY.value,
+                    'target_base': str(target_base),
+                    'source_list': ['*'],
+                },
+            },
+        },
+        'source_node': orm.RemoteData(computer=a_different_computer, remote_path=str(source)),
+    }
+    entry_point_name = 'core.stash'
+    generate_calc_job(fixture_sandbox, entry_point_name, inputs)
+
+    import logging
+
+    with caplog.at_level(logging.WARNING):
+        assert any(
+            'YOUR SETTING MIGHT RESULT IN A SILENT FAILURE!'
+            ' The computer of the source node and the computer of the calculation are strongly advised be the same.'
+            in message
+            for message in caplog.messages
+        )