Journey Drummer Deen Castronovo -- Sentenced to Anger Management

Journey drummer Deen Castronovo is going back to school ... anger management school ... as part of a plea deal in his domestic violence case.

TMZ broke the story ... 47-year-old Castronovo was arrested on January 20 after allegedly attacking his GF at his Oregon home.

Castronovo originally pled not guilty -- but has since worked out a deal with prosecutors in which he agreed to complete 80 hours of community service and complete anger management classes.