[CBAS] Getting error while dropping a dataset - Cannot remove index while it is open.

CBAS Build : 285

Steps to Reproduce :
1. Create a CB bucket - default
2. Load 100000 docs
3. Create a CBAS bucket - default_bucket
4. Create a shadow dataset - default_ds
5. Connect to default_bucket
6. Query CBAS bucket
7. Perform mutations on CB bucket
8. Query CBAS bucket
9. Delete CB bucket
10. Disconnect CBAS bucket
11. Drop Dataset

Issue : Drop dataset fails.
[2016-10-17 22:37:14,655] - [remote_util:2384] INFO - running command.raw on 10.111.151.101: curl -s --data pretty=true --data-urlencode 'statement=drop dataset default_ds;' http://10.111.151.1:8095/analytics/service -v
[2016-10-17 22:37:14,797] - [remote_util:2421] INFO - command executed successfully
[2016-10-17 22:37:14,797] - [cbas_base:179] INFO - {u'status': u'fatal', u'metrics':

{u'elapsedTime': u'55.590592ms', u'executionTime': u'54.813465ms', u'resultSize': u'0', u'resultCount': u'0'}

, u'errors': [

{u'msg': u'Cannot remove index while it is open. (Dataset reference count = 0, Operation tracker number of active operations = 2)', u'code': u'1'}

], u'requestID': u'8bb389f3-2014-45ba-9d94-d606ba069e4d', u'signature': u'*'}

The only way to get rid of this issue is to restart CBAS.