inability to reach some node should not cause entire per-bucket supervisor to fail [was: Rebalance 5->4 nodes is failed with reason bulk_set_vbucket_state_failed]

1.Rebalance in 1->5 nodes
2. Load data (1M), no views or ddocs are created
3. Start rebalance out
4. Created 3 ddocs, 2 view per ddoc
5. Rebalance is failed

2012-08-22 18:18:41.623 ns_orchestrator:4:info:message(ns_1@10.3.3.58) - Starting rebalance, KeepNodes = ['ns_1@10.3.3.64','ns_1@10.3.3.68',
                                 'ns_1@10.3.3.58','ns_1@10.3.3.71'], EjectNodes = ['ns_1@10.3.3.73']

2012-08-22 18:18:41.933 ns_rebalancer:0:info:message(ns_1@10.3.3.58) - Started rebalancing bucket default
2012-08-22 18:18:42.512 ns_vbucket_mover:0:info:message(ns_1@10.3.3.58) - Bucket "default" rebalance does not seem to be swap rebalance
2012-08-22 18:18:45.428 ns_memcached:2:info:message(ns_1@10.3.3.73) - Shutting down bucket "default" on 'ns_1@10.3.3.73' for server shutdown
2012-08-22 18:18:45.747 ns_orchestrator:2:info:message(ns_1@10.3.3.58) - Rebalance exited with reason {{bulk_set_vbucket_state_failed,
                               [{'ns_1@10.3.3.64',
                                 {'EXIT',
                                  {killed,
                                   {gen_server,call,
                                    [{'janitor_agent-default',
                                      'ns_1@10.3.3.64'},
                                     {if_rebalance,<0.22908.39>,
                                      {update_vbucket_state,820,replica,
                                       undefined,'ns_1@10.3.3.58'}},
                                     infinity]}}}}]},
                              [{janitor_agent,bulk_set_vbucket_state,4},
                               {ns_vbucket_mover,
                                update_replication_post_move,3},
                               {ns_vbucket_mover,handle_info,2},
                               {gen_server,handle_msg,5},
                               {proc_lib,init_p_do_apply,3}]}