How to Enable Apply tracing on TARGET site

How To Enable Capture, Propagation, Apply Tracing:Note:421183.1
How to Enable Apply tracing on TARGET site

1.Stop the applyDBMS_APPLY_AD.STOP_APPLY)
2. alter system set events '1349 trace name context forever , level 1024';
3.exec dbms_apply_adm.set_parameter(APPLY_NAME','trace_level',127);
4.Start the apply
5.alter system set events='1349 trace name context off' ;
6.exec dbms_apply_adm.set_parameter(APPLY_NAME','trace_level',null);