Configuring couchbase in tomcat context.xml

I have created a couchbase cluster and have configured two memcached nodes (n1:192.168.91.75:11211, n2:192.168.91.71:11211) if the first node goes down will tomcat able to continue with session’s from the second node (n2:192.168.91.71:11211) automatically with out tomcat restart?. As of now tomcat is not able to continue with the sessions and . Any one can help on this!!

Please find the configuration used

please find the error logs
.ch.SelectionKeyImpl@795b05ca
2015-12-20 08:28:05.981 INFO net.spy.memcached.MemcachedConnection: Reconnecting due to failure to conne
ct to {QA sa=/192.168.91.75:11211, #Rops=0, #Wops=0, #iq=0, topRop=null, topWop=null, toWrite=0, interest
ed=0}
java.net.ConnectException: Connection timed out: no further information
at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:739)
at net.spy.memcached.MemcachedConnection.handleIO(MemcachedConnection.java:642)
at net.spy.memcached.MemcachedConnection.handleIO(MemcachedConnection.java:419)
at net.spy.memcached.MemcachedConnection.run(MemcachedConnection.java:1403)