08904ba8__in_Ruby__Python_and_C_Clients__What_should_the_client_do_
[Error Code Received] LCB_NOT_MY_VBUCKET [What does it mean?] The server, which received this request, is not responsible for this object anymore. This happens during cluster topology changes or rebalancing. [What should the client do?] 
The client automatically fetches a new cluster map from the server and learns about where it should send subsequent requests. In libcouchbase, this error is not really exposed to the user. The library automatically manages reconnecting to the correct server. Retry the operation again after some time.
Handling Runtime Errors in Ruby, Python and C Clients
What should the client do?