public void setComponentName(String componentName) {
    this.componentName = componentName;
  }
Sets the name of the component that this alert instance is associated with.
Component names are not required if the alert definition is scoped for a
service. If specified, there is always a 1:1 mapping between alert
definitions and components.

@param componentName
         the name of the component, or {@code null} if none.
ambari-server/src/main/java/org/apache/ambari/server/orm/entities/AlertHistoryEntity.java