记一次Spring Data Jpa引起的OutOfMemoryError

OOM场景

jpa分页查询

  @Transactional(rollbackFor = Exception.class)
  @Override
  public Resource testJpaOom() {
    int page = 0;
    Page<OrderDO> orderDOPage = orderDao
        .findAll(PageRequest.of(page, OrderConstants.DEFAULT_SIZE));
    int totalPages = orderDOPage.getTotalPages();
    for (; page < totalPages; page++) {
      log.info("start totalPages:[{}],page:[{}]", totalPages, page);
      orderDao.findAll(PageRequest.of(page, OrderConstants.DEFAULT_SIZE));
      log.info("end totalPages:[{}],page:[{}]", totalPages, page);
    }
    return null;
  }

OOM异常

Exception in thread "http-nio-8086-exec-1" java.lang.OutOfMemoryError: GC overhead limit exceeded

修复

 @Transactional(rollbackFor = Exception.class)
  @Override
  public Resource testJpaOom() {
    int page = 0;
    Page<OrderDO> orderDOPage = orderDao
        .findAll(PageRequest.of(page, OrderConstants.DEFAULT_SIZE));
    int totalPages = orderDOPage.getTotalPages();
    for (; page < totalPages; page++) {
      log.info("start totalPages:[{}],page:[{}]", totalPages, page);
      orderDao.findAll(PageRequest.of(page, OrderConstants.DEFAULT_SIZE));
      log.info("end totalPages:[{}],page:[{}]", totalPages, page);
      // 清除持久上下文环境
      entityManager.flush();
      entityManager.clear();
    }
    return null;
  }

总结

托管状态下的bean不会被垃圾回收。关于jpa下bean的状态可以参考

https://my.oschina.net/u/4107179/blog/3041238