InvalidRequestError: One or more mappers failed to initialize - can't proceed with initialization of other mappers.  Original exception was: Class 'kombu.transport.sqlalchemy.Message' is not mapped

galaxy.jobs.handler ERROR 2015-04-19 14:46:00,794 Exception in monitor_step

Traceback (most recent call last):

  File "/mnt/galaxy/data/galaxy/galaxy-dist/lib/galaxy/jobs/handler.py", line 177, in __monitor

    self.__monitor_step()

  File "/mnt/galaxy/data/galaxy/galaxy-dist/lib/galaxy/jobs/handler.py", line 229, in __monitor_step

    jobs_to_check = self.sa_session.query(model.Job).enable_eagerloads(False) \

  File "/mnt/galaxy/data/galaxy/galaxy-dist/eggs/SQLAlchemy-0.9.8-py2.7-linux-x86_64-ucs2.egg/sqlalchemy/orm/scoping.py", line 150, in do

    return getattr(self.registry(), name)(*args, **kwargs)

  File "/mnt/galaxy/data/galaxy/galaxy-dist/eggs/SQLAlchemy-0.9.8-py2.7-linux-x86_64-ucs2.egg/sqlalchemy/orm/session.py", line 1165, in query

    return self._query_cls(entities, self, **kwargs)

  File "/mnt/galaxy/data/galaxy/galaxy-dist/eggs/SQLAlchemy-0.9.8-py2.7-linux-x86_64-ucs2.egg/sqlalchemy/orm/query.py", line 108, in __init__

    self._set_entities(entities)

  File "/mnt/galaxy/data/galaxy/galaxy-dist/eggs/SQLAlchemy-0.9.8-py2.7-linux-x86_64-ucs2.egg/sqlalchemy/orm/query.py", line 118, in _set_entities

    self._set_entity_selectables(self._entities)

  File "/mnt/galaxy/data/galaxy/galaxy-dist/eggs/SQLAlchemy-0.9.8-py2.7-linux-x86_64-ucs2.egg/sqlalchemy/orm/query.py", line 151, in _set_entity_selectables

    ent.setup_entity(*d[entity])

  File "/mnt/galaxy/data/galaxy/galaxy-dist/eggs/SQLAlchemy-0.9.8-py2.7-linux-x86_64-ucs2.egg/sqlalchemy/orm/query.py", line 3036, in setup_entity

    self._with_polymorphic = ext_info.with_polymorphic_mappers

  File "/mnt/galaxy/data/galaxy/galaxy-dist/eggs/SQLAlchemy-0.9.8-py2.7-linux-x86_64-ucs2.egg/sqlalchemy/util/langhelpers.py", line 725, in __get__

    obj.__dict__[self.__name__] = result = self.fget(obj)

  File "/mnt/galaxy/data/galaxy/galaxy-dist/eggs/SQLAlchemy-0.9.8-py2.7-linux-x86_64-ucs2.egg/sqlalchemy/orm/mapper.py", line 1877, in _with_polymorphic_mappers

    configure_mappers()

  File "/mnt/galaxy/data/galaxy/galaxy-dist/eggs/SQLAlchemy-0.9.8-py2.7-linux-x86_64-ucs2.egg/sqlalchemy/orm/mapper.py", line 2586, in configure_mappers

    raise e

Once this error occurs, no more jobs execute on the cluster.

Restarting the handler seems to get things moving again, but I’d like to find the source of the failure.

Any ideas?

Brad