Restored datastore close/open
Restored datastore close/open


Former-commit-id: 5b05b80d5ce3e44e1cff2d6ea9ba9caf31422bd2 [formerly e64ba802c7eadde07d5f080d6358f2187c142d3f]
Former-commit-id: 2e80026ffa37eb823366d80395d787fdd7a57b83
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine