Hanganalyze and Systemstate collection during RAC hang

During hanging situation in database, you may do :

Collection commands for Hanganalyze and Systemstate: RAC

sqlplus '/ as sysdba'
oradebug setorapname reco
oradebug unlimit
oradebug -g all hanganalyze 3
oradebug -g all hanganalyze 3
oradebug -g all dump systemstate 258
oradebug -g all dump systemstate 258
SQL> oradebug tracefile_name

Then upload alert.log and in case hanging reoccur.