Please let me how to upgrade with latest percona xtraDB cluster and also let me know what i need take care about my running database.
Upgrading XtraDB cluster is not a trivial matter, the best and safest way to do it is to shutdown the server just like you do it for standard mysql, /etc/init.d/mysql stop. Then update/upgrade the server using your update tool [apt/yum/yast]. After the update you can then start mysql with /etc/init.d/mysql start. It is advisable though to shutdown nodes one at a time.
Percona XtraDB Cluster 5.5.34-23.7.6 has just been released by the way.