java - 带有 JPA : CommandLineRunner finish delayed 的 Spring Boot 2.3

Question

我在 Spring Boot 2.3.3 上有一个使用 JPA 的 CommandLineRunner，它在完成后有 1 分钟的延迟(见下面的日志)。即使不存在实体类并且没有 JPA 操作，也会发生这种情况。它可以通过仅由一个主要为空的主类组成​​的项目重现。

这在 2.2.7 版本中没有出现，但在 2.3.1 中出现了。它不仅发生在 h2 上，也发生在其他数据库(derby、oracle)上。如果我只使用 spring-boot-starter-data-jdbc 而不是 spring-boot-starter-data-jpa 则没有延迟。

有什么办法可以避免这种延迟吗？

2020-09-01 10:51:57.408  INFO 30314 --- [           main] testcase.SlowShutdown                    : Starting SlowShutdown on io with PID 30314 
2020-09-01 10:51:57.410  INFO 30314 --- [           main] testcase.SlowShutdown                    : No active profile set, falling back to default profiles: default
2020-09-01 10:51:57.858  INFO 30314 --- [           main] .s.d.r.c.RepositoryConfigurationDelegate : Bootstrapping Spring Data JPA repositories in DEFERRED mode.
2020-09-01 10:51:57.873  INFO 30314 --- [           main] .s.d.r.c.RepositoryConfigurationDelegate : Finished Spring Data repository scanning in 10ms. Found 0 JPA repository interfaces.
2020-09-01 10:51:58.095  INFO 30314 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
2020-09-01 10:51:58.100  INFO 30314 --- [           main] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Starting...
2020-09-01 10:51:58.171  INFO 30314 --- [           main] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Start completed.
2020-09-01 10:51:58.216  INFO 30314 --- [         task-1] o.hibernate.jpa.internal.util.LogHelper  : HHH000204: Processing PersistenceUnitInfo [name: default]
2020-09-01 10:51:58.243  INFO 30314 --- [         task-1] org.hibernate.Version                    : HHH000412: Hibernate ORM core version 5.4.20.Final
2020-09-01 10:51:58.274  INFO 30314 --- [           main] DeferredRepositoryInitializationListener : Triggering deferred initialization of Spring Data repositories…
2020-09-01 10:51:58.274  INFO 30314 --- [           main] DeferredRepositoryInitializationListener : Spring Data repositories initialized!
2020-09-01 10:51:58.282  INFO 30314 --- [           main] testcase.SlowShutdown                    : Started SlowShutdown in 1.118 seconds (JVM running for 1.579)
2020-09-01 10:51:58.283  INFO 30314 --- [           main] testcase.SlowShutdown                    : start
2020-09-01 10:51:58.315  INFO 30314 --- [         task-1] o.hibernate.annotations.common.Version   : HCANN000001: Hibernate Commons Annotations {5.1.0.Final}
2020-09-01 10:51:58.387  INFO 30314 --- [         task-1] org.hibernate.dialect.Dialect            : HHH000400: Using dialect: org.hibernate.dialect.H2Dialect
2020-09-01 10:51:58.498  INFO 30314 --- [         task-1] o.h.e.t.j.p.i.JtaPlatformInitiator       : HHH000490: Using JtaPlatform implementation: [org.hibernate.engine.transaction.jta.platform.internal.NoJtaPlatform]
2020-09-01 10:51:58.502  INFO 30314 --- [         task-1] j.LocalContainerEntityManagerFactoryBean : Initialized JPA EntityManagerFactory for persistence unit 'default'
2020-09-01 10:52:58.512  INFO 30314 --- [extShutdownHook] j.LocalContainerEntityManagerFactoryBean : Closing JPA EntityManagerFactory for persistence unit 'default'
2020-09-01 10:52:58.513  INFO 30314 --- [extShutdownHook] .SchemaDropperImpl$DelayedDropActionImpl : HHH000477: Starting delayed evictData of schema as part of SessionFactory shut-down'
2020-09-01 10:52:58.519  INFO 30314 --- [extShutdownHook] o.s.s.concurrent.ThreadPoolTaskExecutor  : Shutting down ExecutorService 'applicationTaskExecutor'
2020-09-01 10:52:58.521  INFO 30314 --- [extShutdownHook] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Shutdown initiated...
2020-09-01 10:52:58.529  INFO 30314 --- [extShutdownHook] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Shutdown completed.

代码:

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.3.3.RELEASE</version>
    <relativePath/>
  </parent>
  <groupId>test</groupId>
  <artifactId>slowshutdown</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <name>slowshutdown</name>
  <description>slowshutdown</description>
  <properties>
    <java.version>11</java.version>
  </properties>
  <dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
    <dependency>
      <groupId>com.h2database</groupId>
      <artifactId>h2</artifactId>
      <scope>runtime</scope>
    </dependency>
  </dependencies>
  <build>
    <plugins>
      <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
      </plugin>
    </plugins>
  </build>
</project>

主类:

package testcase;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;


@SpringBootApplication
public class SlowShutdown implements CommandLineRunner {
  private static final Log log = LogFactory.getLog(SlowShutdown.class);

  public static void main(String[] args) {
    SpringApplication.run(SlowShutdown.class, args);
  }

  @Override
  public void run(String... args) throws Exception {
    log.info("start");
  }
}

Answer 1

Spring Boot 2.3 版本附带 Spring Data 的新主要版本。

正如他们在 documentation 中指出的那样，他们更改了 JPA 存储库的默认 BootstrapMode:

As of #16230, the default BootstrapMode for JPA repositories is now "deferred" so as to improve startup time. You can revert that new default with the spring.data.jpa.repositories.bootstrap-mode=default configuration property.

为避免延迟，您只需要创建一个application.properties文件，并按照说明定义属性spring.data.jpa.repositories.bootstrap-mode :

spring.data.jpa.repositories.bootstrap-mode=default