public class Products {
    @OneToMany(mappedBy = "parentId")
    private List<Products> productsList;

    private static final long serialVersionUID = 1L;

    @Id
    @NotNull
    @Column(name = "ID")
    private String id;
    @Column(name = "CODE")
    private String code;
    @JoinColumn(name = "PARENT_CODE", referencedColumnName = "CODE")
    @ManyToOne
    private Products parentId;
    @Size(max = 1000)
    @Column(name = "NAME")
    private String name;
    @JoinColumn(name = "UNIT_ID", referencedColumnName = "ID", insertable=false, updatable=true)
    @ManyToOne(optional = false, fetch = FetchType.LAZY)
    private Unit unitId;

public class Unit implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "ID")
    private Long id;
    @Basic(optional = false)
    @NotNull
    @Size(min = 1, max = 25)
    @Column(name = "NAME")
    private String name;
    @OneToMany(mappedBy="unitId", cascade=CascadeType.ALL)
    private List<Products> productses;

Products products = new Products();
 products.setId(createGuid());
 products.setCode(gson.getCode());
 products.setName(gson.getProductName());
 products.setParentId(new Products(gson.getParentId()));
 products.setUnitId(new Unit(gson.getUnitName()));
 em.persist(products);

During synchronization a new object was found through a relationship that was not marked cascade PERSIST: kz.aoz.entity.Unit@7b63132a.