Spring Database Load Test: How to Free Connections

Question

I was just trying to simplify my problem in a small Show-Case application.
Connection does not seem to close until Thread completes. Check it out

Dependency Information:

Servlet Engine : Apache Tomcat / 8.5.5
JPA Provider: Hibernate

My pom.xml:

<?xml version="1.0" encoding="UTF-8"?>
<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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>...</groupId>
    <artifactId>***-service</artifactId>
    <version>0.0.1</version>
    <packaging>jar</packaging>

    <name>...</name>
    <description>...</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter</artifactId>
        <version>1.4.1.RELEASE</version>
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
        <spring.cloud.release.version>Brixton.SR2</spring.cloud.release.version>
    </properties>

    <dependencies>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-rest</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <!-- eureka discovery client -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>

        <!-- for unit tests -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <!-- for rest documentation -->
        <dependency>
            <groupId>org.springframework.restdocs</groupId>
            <artifactId>spring-restdocs-mockmvc</artifactId>
            <scope>test</scope>
        </dependency>

        <!-- for (un)marshalling of json / xml -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.dataformat</groupId>
            <artifactId>jackson-dataformat-xml</artifactId>
        </dependency>

        <dependency>
            <!-- jsoup HTML parser library @ http://jsoup.org/ -->
            <groupId>org.jsoup</groupId>
            <artifactId>jsoup</artifactId>
            <version>1.9.2</version>
        </dependency>

    </dependencies>

    <dependencyManagement>
        <dependencies>
            <!-- also needed for eureka discovery -->
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring.cloud.release.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <finalName>${artifactId}</finalName>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <executable>true</executable>
                    <outputDirectory>${dir}</outputDirectory>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

I have a Spring boot server with MYSQL as DB. When I load a load (JMeter) with over 100 threads / users, I get this exception:

org.apache.tomcat.jdbc.pool.PoolExhaustedException: [http-nio-8015-exec-195] Timeout: pool is empty. Failed to get connection in 60 seconds, not available [size: 50; busy: 50; idling: 0; lastwait: 60,000].

My data source configuration:

spring.datasource.tomcat.minIdle = 0
spring.datasource.tomcat.maxIdle = 10
spring.datasource.tomcat.maxActive = 50
spring.datasource.tomcat.maxWait = 60000
spring.datasource.tomcat.testOnBorrow = true
spring.datasource.tomcat.timeBetweenEvictionRunsMillis = 1800000 // Updated
spring.datasource.tomcat.numTestsPerEvictionRun = 50  // Updated
spring.datasource.tomcat.minEvictableIdleTimeMillis = 10
spring.datasource.tomcat.validationQuery = SELECT 1
spring.datasource.tomcat.testWhileIdle = true

- SELECT * FROM TABLE WHERE deletedat IS NULL. 4000 0,01 ( mysql CLI).
Neor Profile SQL MYSQL. , . , .

, CrudRepository:

public interface MyRepository extends CrudRepository<MyModel, String> {
    @Query("SELECT m from MyModel m WHERE m.deletedAt IS NULL")
    List<MyModel> findWhereDeletedAtIsNull();
}

List<MyModel> myModelList = myRepository.findWhereDeletedAtIsNull();

?
, .

Hibernate:

spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQL5Dialect  

Answer 1

jpa OpenEntityManagerInViewInterceptor, JPA EntityManager . , ( ) (com.example.api.UserService.getAllUser()).

DB .

, OpenEntityManagerInViewInterceptor, application.properties

spring.jpa.open-in-view = false

.

. :  1. , OpenEntityManagerInViewInterceptor

Answer 2

logAbandoned. , Tomcat JDBC , , . , : , .

java.sql.SQLException: Connection has already been closed , , 50 , . , 50 ( "" ), , , . .