Spring Tool Suite中HikariPool线程未停止致内存泄漏告警求助

问题描述 #

在Spring Tool Suite 4中创建的小型Spring Boot应用运行时出现如下告警：

"Web应用[ROOT]启动了名为[HikariPool-1 housekeeper]的线程但未正确停止，这很可能导致内存泄漏。"

反复检查业务代码未发现错误，代码如下：

业务代码 #

Bootstrap初始化类 #

@Component
public class BootStrapData implements CommandLineRunner {

private final AuthorRepository authorRepository;
private final BookRepository bookRepository;
private final PublisherRepository publisherRepository;

public BootStrapData(AuthorRepository authorRepository, BookRepository bookRepository, PublisherRepository publisherRepository) {
    this.authorRepository = authorRepository;
    this.bookRepository = bookRepository;
    this.publisherRepository = publisherRepository;
}

@Override
public void run(String... args) throws Exception {

    System.out.println("Started in Bootstrap");

    Publisher publisher = new Publisher();
    publisher.setName("SFG Publishing");
    publisher.setCity("St Petersburg");
    publisher.setState("FL");

    publisherRepository.save(publisher);

    System.out.println("Publisher Count: " + publisherRepository.count());

    Author eric = new Author("Eric", "Evans");
    Book ddd = new Book("Domain Driven Design", "123123");
    eric.getBooks().add(ddd);
    ddd.getAuthors().add(eric);

    ddd.setPublisher(publisher);
    publisher.getBooks().add(ddd);

    authorRepository.save(eric);
    bookRepository.save(ddd);
    publisherRepository.save(publisher);

    Author rod = new Author("Rod", "Johnson");
    Book noEJB = new Book("J2EE Development without EJB", "3939459459");
    rod.getBooks().add(noEJB);
    noEJB.getAuthors().add(rod);

    noEJB.setPublisher(publisher);
    publisher.getBooks().add(noEJB);

    authorRepository.save(rod);
    bookRepository.save(noEJB);
    publisherRepository.save(publisher);

    System.out.println("Number of Books: " + bookRepository.count());
    System.out.println("Publisher Number of Books: " + publisher.getBooks().size());
   }
}

实体类 #

Book实体

@Entity
public class Book {

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;

private String title;
private String isbn;

@ManyToOne
private Publisher publisher;

@ManyToMany
@JoinTable(name = "author_book", joinColumns = @JoinColumn(name = "book_id"),
        inverseJoinColumns = @JoinColumn(name = "author_id"))
private Set<Author> authors = new HashSet<>();

public Book() {
}

public Book(String title, String isbn) {
    this.title = title;
    this.isbn = isbn;
}

public Publisher getPublisher() {
    return publisher;
}

public void setPublisher(Publisher publisher) {
    this.publisher = publisher;
}

public Long getId() {
    return id;
}

public void setId(Long id) {
    this.id = id;
}

public String getTitle() {
    return title;
}

public void setTitle(String title) {
    this.title = title;
}

public String getIsbn() {
    return isbn;
}

public void setIsbn(String isbn) {
    this.isbn = isbn;
}

public Set<Author> getAuthors() {
    return authors;
}

public void setAuthors(Set<Author> authors) {
    this.authors = authors;
}

@Override
public String toString() {
    return "Book{" +
            "id=" + id +
            ", title='" + title + '\'' +
            ", isbn='" + isbn + '\'' +
            ", authors=" + authors +
            '}';
}

@Override
public boolean equals(Object o) {
    if (this == o) return true;
    if (o == null || getClass() != o.getClass()) return false;

    Book book = (Book) o;

    return id != null ? id.equals(book.id) : book.id == null;
}

@Override
public int hashCode() {
    return id != null ? id.hashCode() : 0;
   }
}

Author实体

@Entity
public class Author {

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;

private String firstName;
private String lastName;

@ManyToMany(mappedBy = "authors")
private Set<Book> books = new HashSet<>();

public Author() {
}

public Author(String firstName, String lastName) {
    this.firstName = firstName;
    this.lastName = lastName;
}

public Long getId() {
    return id;
}

public void setId(Long id) {
    this.id = id;
}

public String getFirstName() {
    return firstName;
}

public void setFirstName(String firstName) {
    this.firstName = firstName;
}

public String getLastName() {
    return lastName;
}

public void setLastName(String lastName) {
    this.lastName = lastName;
}

public Set<Book> getBooks() {
    return books;
}

public void setBooks(Set<Book> books) {
    this.books = books;
}

@Override
public String toString() {
    return "Author{" +
            "id=" + id +
            ", firstName='" + firstName + '\'' +
            ", lastName='" + lastName + '\'' +
            ", books=" + books +
            '}';
}

@Override
public boolean equals(Object o) {
    if (this == o) return true;
    if (o == null || getClass() != o.getClass()) return false;

    Author author = (Author) o;

    return id != null ? id.equals(author.id) : author.id == null;
}

@Override
public int hashCode() {
    return id != null ? id.hashCode() : 0;
   }
}

Publisher实体

@Entity
public class Publisher {

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;

private String name;
private String addressLine1;
private String city;
private String state;
private String zip;

@OneToMany
@JoinColumn(name = "publisher_id")
private Set<Book> books = new HashSet<>();

public Publisher() {
}

public Set<Book> getBooks() {
    return books;
}

public void setBooks(Set<Book> books) {
    this.books = books;
}

@Override
public String toString() {
    return "Publisher{" +
            "id=" + id +
            ", name='" + name + '\'' +
            ", addressLine1='" + addressLine1 + '\'' +
            ", city='" + city + '\'' +
            ", state='" + state + '\'' +
            ", zip='" + zip + '\'' +
            '}';
}

@Override
public boolean equals(Object o) {
    if (this == o) return true;
    if (o == null || getClass() != o.getClass()) return false;

    Publisher publisher = (Publisher) o;

    return id != null ? id.equals(publisher.id) : publisher.id == null;
}

@Override
public int hashCode() {
    return id != null ? id.hashCode() : 0;
}

public Long getId() {
    return id;
}

public void setId(Long id) {
    this.id = id;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public String getAddressLine1() {
    return addressLine1;
}

public void setAddressLine1(String addressLine1) {
    this.addressLine1 = addressLine1;
}

public String getCity() {
    return city;
}

public void setCity(String city) {
    this.city = city;
}

public String getState() {
    return state;
}

public void setState(String state) {
    this.state = state;
}

public String getZip() {
    return zip;
}

public void setZip(String zip) {
    this.zip = zip;
}

仓库接口 #

public interface AuthorRepository extends CrudRepository<Author, Long>{

}

public interface BookRepository extends CrudRepository<Book, Long>{

}

public interface PublisherRepository extends CrudRepository<Publisher, Long>{

}

解决方案 #

这个告警本质上是Tomcat在应用关闭时的误报，并非业务代码错误导致，可通过以下方式处理：

1. 配置Hikari连接池优雅关闭
   在application.properties中添加：

   spring.datasource.hikari.shutdown-timeout=5000
   

   强制连接池在应用关闭时等待5秒完成线程销毁。

2. 关闭Tomcat后台线程检测
   若确认是误报，可关闭Tomcat的后台处理器延迟检测：

   server.tomcat.background-processor-delay=-1
   

3. 升级Spring Boot版本
   旧版本Spring Boot与HikariCP存在生命周期协调问题，升级到2.7.x及以上稳定版可解决该类告警。

4. 正常停止应用
   在STS中停止应用时，使用标准"Stop"按钮而非强制终止，确保Spring容器触发Bean销毁流程，Hikari连接池会自动关闭后台线程。

内容的提问来源于stack exchange，提问作者Krati Vaishnao