We hit this error during "glance-manage db_sync":

Any idea what the root cause is and how to fix it?

We have the following rpms installed (thought related).

Debug: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns: Sleeping for 5 seconds between tries

Debug: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns: Exec try 10/10

Debug: Exec[neutron-db-sync](provider=posix): Executing 'neutron-db-manage  upgrade heads'

Debug: Executing: 'neutron-db-manage  upgrade heads'

Debug: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns: Sleeping for 5 seconds between tries

Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns: Traceback (most recent call last):

Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/bin/neutron-db-manage", line 10, in <module>

Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     sys.exit(main())

Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/lib/python2.7/site-packages/neutron/db/migration/cli.py", line 657, in main

Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     return_val |= bool(CONF.command.func(config, CONF.command.name))

Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/lib/python2.7/site-packages/neutron/db/migration/cli.py", line 179, in do_upgrade

Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     run_sanity_checks(config, revision)

Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/lib/python2.7/site-packages/neutron/db/migration/cli.py", line 641, in run_sanity_checks

Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     script_dir.run_env()

Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/lib/python2.7/site-packages/alembic/script/base.py", line 425, in run_env

Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     util.load_python_file(self.dir, 'env.py')

Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/lib/python2.7/site-packages/alembic/util/pyfiles.py", line 81, in load_python_file

Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     module = load_module_py(module_id, path)

Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/lib/python2.7/site-packages/alembic/util/compat.py", line 141, in load_module_py

Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     mod = imp.load_source(module_id, path, fp)

Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/lib/python2.7/site-packages/neutron/db/migration/alembic_migrations/env.py", line 24, in <module>

Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     from neutron.db.migration.models import head  # noqa

Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/lib/python2.7/site-packages/neutron/db/migration/models/head.py", line 28, in <module>

Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     from neutron.common import utils

Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/lib/python2.7/site-packages/neutron/common/utils.py", line 35, in <module>

Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     import eventlet

Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/lib/python2.7/site-packages/eventlet/__init__.py", line 10, in <module>

Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     from eventlet import convenience

Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/lib/python2.7/site-packages/eventlet/convenience.py", line 4, in <module>

Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     from eventlet import greenpool

Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns: ImportError: cannot import name greenpool

Error: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]: Failed to call refresh: 'neutron-db-manage  upgrade heads' returned 1 instead of one of [0]

Error: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]: 'neutron-db-manage  upgrade heads' returned 1 instead of one of [0]

Notice: /Stage[main]/Neutron::Deps/Anchor[neutron::dbsync::end]: Dependency Exec[neutron-db-sync] has failures: true