[upgrade] rebalance for online upgrade 2.0.0->2.0.1-139-rel cluster hungs up

centos 2 nodes 2.0.0 cluster -> 1 node 2.0.1-139-rel cluster <manifest> <remote name="couchbase" fetch=" git://github.com/couchbase/ "/> <remote name="membase" fetch=" git://github.com/membase/ "/> <remote name="apache" fetch=" git://github.com/apache/ "/> <remote name="erlang" fetch=" git://github.com/erlang/ "/> <default remote="couchbase" revision="master"/> <project name="tlm" path="tlm" revision="12abea946eafd7411273d18a10ae1f84390db3d4"> <copyfile src="Makefile.top" dest="Makefile"/> </project> <project name="bucket_engine" path="bucket_engine" revision="1495eb770b9735dd791c483eee7e69641f82f09c"/> <project name="ep-engine" path="ep-engine" revision="35e248148abc810ab67715e86417191cd73e39dd"/> <project name="libconflate" path="libconflate" revision="2cc8eff8e77d497d9f03a30fafaecb85280535d6"/> <project name="libmemcached" path="libmemcached" revision="ca739a890349ac36dc79447e37da7caa9ae819f5" remote="membase"/> <project name="libvbucket" path="libvbucket" revision="026c79ae424a6daed4bb9345e86cc8fc21759b28"/> <project name="membase-cli" path="membase-cli" revision="d510a56bd07e7da5743d192300d73e8d7db2f8d2" remote="membase"/> <project name="memcached" path="memcached" revision="e6f892cf7bd61e91a79be0d8d2c6f075d3c4ae1b" remote="membase"/> <project name="moxi" path="moxi" revision="52a5fa887bfff0bf719c4ee5f29634dd8707500e"/> <project name="ns_server" path="ns_server" revision="1fa77a48cc3ea1fcdaf5a686ebe5b45de202553d"/> <project name="portsigar" path="portsigar" revision="1bc865e1622fb93a3fe0d1a4cdf18eb97ed9d600"/> <project name="sigar" path="sigar" revision="63a3cd1b316d2d4aa6dd31ce8fc66101b983e0b0"/> <project name="couchbase-examples" path="couchbase-examples" revision="cd9c8600589a1996c1ba6dbea9ac171b937d3379"/> <project name="couchbase-python-client" path="couchbase-python-client" revision="006c1aa8b76f6bce11109af8a309133b57079c4c"/> <project name="couchdb" path="couchdb" revision="f3bff70f9d71ec252fb125c058db9e6bdd607da4"/> <project name="couchdbx-app" path="couchdbx-app" revision="b86a1a83ab74f1ef77ec9bdc814b81d739bfd930"/> <project name="couchstore" path="couchstore" revision="b5937c4479bf05dcc67264efe19abaf52870a127"/> <project name="geocouch" path="geocouch" revision="8997159c44282cfcd89ea9984dd8c0944a35b2b4"/> <project name="testrunner" path="testrunner" revision="adaa32cbec66e24462feea0d5561647500bc9c6e"/> <project name="otp" path="otp" revision="b6dc1a844eab061d0a7153d46e7e68296f15a504" remote="erlang"/> <project name="icu4c" path="icu4c" revision="26359393672c378f41f2103a8699c4357c894be7" remote="couchbase"/> <project name="snappy" path="snappy" revision="5681dde156e9d07adbeeab79666c9a9d7a10ec95" remote="couchbase"/> <project name="v8" path="v8" revision="447decb75060a106131ab4de934bcc374648e7f2" remote="couchbase"/> <project name="gperftools" path="gperftools" revision="8f60ba949fb8576c530ef4be148bff97106ddc59" remote="couchbase"/> <project name="pysqlite" path="pysqlite" revision="0ff6e32ea05037fddef1eb41a648f2a2141009ea" remote="couchbase"/> </manifest>