How can I configure the logging level of couchbase? What does it use- log4j/logback or something else?
What version are you using?
Take a look at this blog post: http://blog.couchbase.com/logging-couchbase-java-client
Yes, follow the blog for the 1.4 SDK, for 2.0 see http://docs.couchbase.com/developer/java-2.0/logging.html