[upgrade] Offline upgrade from 4.0.0 to vulcan 5.5.0-1911 teared down 4.0.0 cluster.

[root@s62216-cnt65 ~]# rpm -U couchbase-server-enterprise-5.5.0-1911-centos6.x86_64.rpm 

Stopping couchbase-server

[  OK  ]

Minimum RAM required  : 4 GB

System RAM configured : 3.79 GB

Minimum number of processors required : 4 cores

Number of processors on the system    : 4 cores

warning: /opt/couchbase/etc/couchdb/local.ini saved as /opt/couchbase/etc/couchdb/local.ini.rpmsave

warning: /opt/couchbase/var/lib/couchbase/config/config.dat saved as /opt/couchbase/var/lib/couchbase/config/config.dat.rpmsave

warning: /opt/couchbase/var/lib/couchbase/ip saved as /opt/couchbase/var/lib/couchbase/ip.rpmsave

Upgrading couchbase-server ...

  /opt/couchbase/bin/install/cbupgrade -c /opt/couchbase/var/lib/couchbase/config -a yes 

Automatic mode: running without interactive questions or confirmations.

Analysing...

Previous config.dat file is /opt/couchbase/var/lib/couchbase/config/config.dat.rpmsave

Target node: ns_1@172.23.106.57

Traceback (most recent call last):

  File "/opt/couchbase/bin/install/cbupgrade", line 487, in <module>

    main()

  File "/opt/couchbase/bin/install/cbupgrade", line 346, in main

    print 'Error getting node config": {}'.format(p.communicate()[0])

ValueError: zero length field name in format

warning: %post(couchbase-server-5.5.0-1911.x86_64) scriptlet failed, exit status 1

Starting couchbase-server

[  OK  ]

You have successfully installed Couchbase Server.

Please browse to http://s62216-cnt65:8091/ to configure your server.

Please refer to http://couchbase.com for additional resources.

Please note that you have to update your firewall configuration to

allow connections to the following ports:

4369, 8091 to 8094, 9100 to 9105, 9998, 9999, 11207, 11209 to 11211,

11214, 11215, 18091 to 18093, and from 21100 to 21299.

By using this software you agree to the End User License Agreement.

See /opt/couchbase/LICENSE.txt.