Undertaker crash when a DID is attach/detached many times
Motivation
----------
The undertaker crash when a DID is attach/detached many times. The problem is due to the archival in the history table : https://github.com/rucio/rucio/blame/master/lib/rucio/core/did.py#L714 .
diff --git a/lib/rucio/core/did.py b/lib/rucio/core/did.py
index 4f918a7d8..6ee1e852c 100644
--- a/lib/rucio/core/did.py
+++ b/lib/rucio/core/did.py
@@ -14,7 +14,7 @@
 #
 # Authors:
 # - Vincent Garonne <vgaronne@gmail.com>, 2013-2018
-# - Martin Barisits <martin.barisits@cern.ch>, 2013-2017
+# - Martin Barisits <martin.barisits@cern.ch>, 2013-2018
 # - Cedric Serfon <cedric.serfon@cern.ch>, 2013-2018
 # - Ralph Vigne <ralph.vigne@cern.ch>, 2013
 # - Mario Lassnig <mario.lassnig@cern.ch>, 2013-2018
@@ -728,7 +728,6 @@ def detach_dids(scope, name, dids, session=None):
                                                              created_at=associ_did.created_at,
                                                              updated_at=associ_did.updated_at,
                                                              deleted_at=datetime.utcnow())
-        new_detach = session.merge(new_detach)
         new_detach.save(session=session, flush=False)
 
         # Send message for AMI. To be removed in the future when they use the DETACH messages
@@ -864,9 +863,11 @@ def list_content_history(scope, name, session=None):
     :param session: The database session in use.
     """
     try:
+        # query = session.query(models.DataIdentifierAssociationHistory).\\
+        #    with_hint(models.DataIdentifierAssociationHistory,
+        #              "INDEX(CONTENTS_HISTORY CONTENTS_HIST_PK)", 'oracle').\\
+        #    filter_by(scope=scope, name=name)
         query = session.query(models.DataIdentifierAssociationHistory).\\
-            with_hint(models.DataIdentifierAssociationHistory,
-                      "INDEX(CONTENTS_HISTORY CONTENTS_HIST_PK)", 'oracle').\\
             filter_by(scope=scope, name=name)
         for tmp_did in query.yield_per(5):
             yield {'scope': tmp_did.child_scope, 'name': tmp_did.child_name,
diff --git a/lib/rucio/db/sqla/models.py b/lib/rucio/db/sqla/models.py
index 74b8571ef..848a8b26a 100644
--- a/lib/rucio/db/sqla/models.py
+++ b/lib/rucio/db/sqla/models.py
@@ -579,8 +579,11 @@ class DataIdentifierAssociationHistory(BASE, ModelBase):
     rule_evaluation = Column(Boolean(name='CONTENTS_HIST_RULE_EVAL_CHK'))
     did_created_at = Column(DateTime)
     deleted_at = Column(DateTime)
-    _table_args = (PrimaryKeyConstraint('scope', 'name', 'child_scope', 'child_name', name='CONTENTS_HIST_PK'),
-                   CheckConstraint('DID_TYPE IS NOT NULL', name='CONTENTS_HIST_DID_TYPE_NN'),
+    __mapper_args__ = {
+        'primary_key': [scope, name, child_scope, child_name]
+    }
+    # _table_args = (PrimaryKeyConstraint('scope', 'name', 'child_scope', 'child_name', name='CONTENTS_HIST_PK'),
+    _table_args = (CheckConstraint('DID_TYPE IS NOT NULL', name='CONTENTS_HIST_DID_TYPE_NN'),
                    CheckConstraint('CHILD_TYPE IS NOT NULL', name='CONTENTS_HIST_CHILD_TYPE_NN'),
                    Index('CONTENTS_HISTORY_IDX', 'scope', 'name'))
 
['lib/rucio/db/sqla/models.py', 'lib/rucio/core/did.py']