I'm studying Transaction Routing in Spring, but my application has a runtime problem.
I have two MySQL databases, one for reading and one for reading/write, but my routing configuration is not working, when I apply the read-only configuration, I don't get success.
This is my configurations:
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 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>2.5.1</version>
</parent>
<groupId>br.com.multidatasources</groupId>
<artifactId>multidatasources</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>multidatasources</name>
<properties>
<java.version>11</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-configuration-processor</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
application.properties
# Database master
master.datasource.url=jdbc:mysql://localhost:3306/billionaires?createDatabaseIfNotExist=true&useTimezone=true&serverTimezone=UTC
master.datasource.username=root
master.datasource.password=root
# Database slave
slave.datasource.url=jdbc:mysql://localhost:3307/billionaires?createDatabaseIfNotExist=true&useTimezone=true&serverTimezone=UTC
slave.datasource.username=root
slave.datasource.password=root
# Database driver
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
# JPA property settings
spring.jpa.database=mysql
spring.jpa.database-platform=org.hibernate.dialect.MySQL8Dialect
DataSourceType.java
public enum DataSourceType {
READ_ONLY,
READ_WRITE
}
TransactionRoutingDataSource.java
public class TransactionRoutingDataSource extends AbstractRoutingDataSource {
@Override
protected Object determineCurrentLookupKey() {
return TransactionSynchronizationManager.isCurrentTransactionReadOnly() ? DataSourceType.READ_ONLY : DataSourceType.READ_WRITE;
}
}
RoutingConfiguration.java
@Configuration
@EnableTransactionManagement
public class RoutingConfiguration {
private final Environment environment;
public RoutingConfiguration(Environment environment) {
this.environment = environment;
}
@Bean
public JpaTransactionManager transactionManager(@Qualifier("entityManagerFactory") LocalContainerEntityManagerFactoryBean entityManagerFactory) {
return new JpaTransactionManager(entityManagerFactory.getObject());
}
@Bean
public LocalContainerEntityManagerFactoryBean entityManagerFactory(@Qualifier("routingDataSource") DataSource routingDataSource) {
LocalContainerEntityManagerFactoryBean bean = new LocalContainerEntityManagerFactoryBean();
bean.setDataSource(routingDataSource);
bean.setPackagesToScan(Billionaires.class.getPackageName());
bean.setJpaVendorAdapter(new HibernateJpaVendorAdapter());
bean.setJpaProperties(additionalProperties());
return bean;
}
@Bean
public DataSource dataSource(@Qualifier("routingDataSource") DataSource routingDataSource) {
return new LazyConnectionDataSourceProxy(routingDataSource);
}
@Bean
public TransactionRoutingDataSource routingDataSource(
@Qualifier("masterDataSource") DataSource masterDataSource,
@Qualifier("slaveDataSource") DataSource slaveDataSource
) {
TransactionRoutingDataSource routingDataSource = new TransactionRoutingDataSource();
Map<Object, Object> dataSourceMap = new HashMap<>();
dataSourceMap.put(DataSourceType.READ_WRITE, masterDataSource);
dataSourceMap.put(DataSourceType.READ_ONLY, slaveDataSource);
routingDataSource.setTargetDataSources(dataSourceMap);
routingDataSource.setDefaultTargetDataSource(masterDataSource());
return routingDataSource;
}
@Bean
public DataSource masterDataSource() {
DriverManagerDataSource dataSource = new DriverManagerDataSource();
dataSource.setUrl(environment.getProperty("master.datasource.url"));
dataSource.setUsername(environment.getProperty("master.datasource.username"));
dataSource.setPassword(environment.getProperty("master.datasource.password"));
return dataSource;
}
@Bean
public DataSource slaveDataSource() {
DriverManagerDataSource dataSource = new DriverManagerDataSource();
dataSource.setUrl(environment.getProperty("slave.datasource.url"));
dataSource.setUsername(environment.getProperty("slave.datasource.username"));
dataSource.setPassword(environment.getProperty("slave.datasource.password"));
return dataSource;
}
private Properties additionalProperties() {
Properties properties = new Properties();
properties.setProperty("hibernate.dialect", "org.hibernate.dialect.MySQL8Dialect");
return properties;
}
}
Billionaires.java
@Entity
@Table(name = "billionaires")
public class Billionaires {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
@Column(name = "first_name")
private String firstName;
@Column(name = "last_name")
private String lastName;
private String career;
public Billionaires() { }
public Billionaires(Long id, String firstName, String lastName, String career) {
this.id = id;
this.firstName = firstName;
this.lastName = lastName;
this.career = career;
}
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 String getCareer() {
return career;
}
public void setCareer(String career) {
this.career = career;
}
}
BillionairesRepository.java
@Repository
public interface BillionairesRepository extends JpaRepository<Billionaires, Long> {
}
BillionairesService.java
@Service
public class BillionairesService {
private final BillionairesRepository billionairesRepository;
public BillionairesService(BillionairesRepository billionairesRepository) {
this.billionairesRepository = billionairesRepository;
}
@Transactional(readOnly = true) // Should be used the READ_ONLY (This point not working)
public List<Billionaires> findAll() {
return billionairesRepository.findAll();
}
@Transactional // Should be used the READ_WRITE
public Billionaires save(Billionaires billionaires) {
return billionairesRepository.save(billionaires);
}
}
In the BillionairesService class, I apply the @Transactional(readOnly = true) on findAll method for use the READ_ONLY data source, but this is not occurring.
The findAll method should be used the READ_ONLY data source and save method should be used the READ_WRITE data source.
Can someone help me fix this problem?
@EnableTransactionManagement. Also check if you are using the correctTransactionSynchronizationManager(there are 2 one reactive and one classic, you should use the latter one!). – Montserrat@EnableTransactionalManagementto creating a beanentityManagerFactory, because without this setting causes the initializing exception: ` *************************** APPLICATION FAILED TO START *************************** Description: Parameter 0 of constructor in br.com.multidatasources.multidatasources.service.BillionairesService required a bean named 'entityManagerFactory' that could not be found. Action: Consider defining a bean named 'entityManagerFactory' in your configuration. ` – HopefullyTransactionSynchronizationManagerI'm using classic, nothing reactive. – Hopefully@EnableTransactionManagementdoesn't create that bean, it only registers the aspect to drive transactions. You should mark yourLazyDataSourceConnectionbean as@Primaryso that it will be used by the auto configured entitymanager. – Montserrat@EnableTransactionManagementand mark myLazyDataSourceConnectionas@Primarybean, but does not working, the application every using onlyREAD_WRITEmode. – Hopefullyspring.jpa.open-in-view=falseconfigured in myapplication.properties, but it is not working. – HopefullyfindAllcalled? If that is from an other@Transactionalmethod it will not switch to a read only connection it will just participate in the current transaction. – Montserrat