[windows]:FTS rebalance_out operation took > 1 hr to complete

Build: Enterprise Edition 7.0.0 build 5014

Scenario:

1. 15 node cluster with couchbase bucket (1 replica)
2. Deployed few fts functions
3. Rebalance out eventing+fts node

   +----------------+---------------+-----------------------+----------------+--------------+

   | Nodes | Services | Version | CPU | Status |

   +----------------+---------------+-----------------------+----------------+--------------+

   | 172.23.120.100 | kv | 7.0.0-5014-enterprise | 17.6043133693 | Cluster node |

   | 172.23.136.114 | index, n1ql | 7.0.0-5014-enterprise | 2.63076756414 | Cluster node |

   | 172.23.136.106 | index, n1ql | 7.0.0-5014-enterprise | 36.5121957317 | Cluster node |

   | 172.23.136.107 | cbas | 7.0.0-5014-enterprise | 1.49752495875 | Cluster node |

   | 172.23.120.113 | kv | 7.0.0-5014-enterprise | 12.8772853786 | Cluster node |

   | 172.23.120.117 | kv | 7.0.0-5014-enterprise | 12.8258333333 | Cluster node |

   | 172.23.138.127 | eventing, fts | 7.0.0-5014-enterprise | 3.2941117648 | Cluster node |

   | 172.23.121.81 | index, n1ql | 7.0.0-5014-enterprise | 13.6955706488 | Cluster node |

   | 172.23.120.144 | backup | 7.0.0-5014-enterprise | 1.72978999567 | Cluster node |

   | 172.23.136.108 | cbas | 7.0.0-5014-enterprise | 0.286669055575 | Cluster node |

   | 172.23.136.112 | eventing, fts | 7.0.0-5014-enterprise | 4.43064872297 | Cluster node |

   | 172.23.136.115 | cbas | 7.0.0-5014-enterprise | 2.05748285431 | Cluster node |

   | 172.23.136.113 | kv | 7.0.0-5014-enterprise | 39.4535091082 | Cluster node |

   | 172.23.136.110 | eventing, fts | 7.0.0-5014-enterprise | 3.41 | --- OUT ---> |

   | 172.23.136.105 | kv | 7.0.0-5014-enterprise | 9.53166666667 | Cluster node |

   +----------------+---------------+-----------------------+----------------+--------------+

Observation:

Rebalance operation got stuck around 41.8%

Starting rebalance, KeepNodes = ['ns_1@172.23.120.100','ns_1@172.23.136.114',

'ns_1@172.23.136.106','ns_1@172.23.136.107',

'ns_1@172.23.120.113','ns_1@172.23.120.117',

'ns_1@172.23.138.127','ns_1@172.23.121.81',

'ns_1@172.23.120.144','ns_1@172.23.136.108',

'ns_1@172.23.136.112','ns_1@172.23.136.115',

'ns_1@172.23.136.113','ns_1@172.23.136.105'], 

EjectNodes = ['ns_1@172.23.136.110'], 

Failed over and being ejected nodes = []; no delta recovery nodes;

Operation Id = cea6ba07344c792eb6a229fa2bc04a6f