DB Replication 설정하기 #399
Comments
PrimaryDB
DB 들어가서 확인
Replica DB
참고 |
Spring Boot에서 Master-Slave 설정하기기본적으로 Spring Boot는 하나의 DataSource만 등록되어 있는데, application.properties spring.datasource.master.jdbc-url=jdbc:mariadb://{master ip:port}/gpu_is_mine?characterEncoding=UTF-8&serverTimezone=UTC
spring.datasource.master.driverClassName=org.mariadb.jdbc.Driver
spring.datasource.master.username=root
spring.datasource.master.password=password
spring.datasource.slave.jdbc-url=jdbc:mariadb://{slave ip:port}/gpu_is_mine?characterEncoding=UTF-8&serverTimezone=UTC
spring.datasource.slave.driverClassName=org.mariadb.jdbc.Driver
spring.datasource.slave.username=root
spring.datasource.slave.password=passwordReplicationRoutingDataSource.java public class ReplicationRoutingDataSource extends AbstractRoutingDataSource {
@Override
protected Object determineCurrentLookupKey() {
return TransactionSynchronizationManager.isCurrentTransactionReadOnly() ? "slave" : "master";
}
}DataSourceConfig.java @Configuration(proxyBeanMethods=flase_
public class DataSourceConfig {
@Bean
@ConfigurationProperties(prefix = "spring.datasource.master")
public DataSource masterDataSource() {
return DataSourceBuilder.create().type(HikariDataSource.class).build();
}
@Bean
@ConfigurationProperties(prefix = "spring.datasource.slave")
public DataSource slaveDataSource() {
return DataSourceBuilder.create().type(HikariDataSource.class).build();
}
@Bean
public DataSource routingDataSource() {
var routingDataSource = new ReplicationRoutingDataSource();
var dataSourceMap = new HashMap<>();
DataSource slaveDataSource = slaveDataSource();
DataSource masterDataSource = masterDataSource();
dataSourceMap.put("master", masterDataSource);
dataSourceMap.put("slave", slaveDataSource);
routingDataSource.setTargetDataSources(dataSourceMap);
routingDataSource.setDefaultTargetDataSource(masterDataSource);
return routingDataSource;
}
@Bean
public DataSource dataSource() {
return new LazyConnectionDataSourceProxy(routingDataSource());
}
}참고 블로그 에서는 @Configuration
@EnableAutoConfiguration(exclude = {DataSourceAutoConfiguration.class})
@EnableTransactionManagement
@EnableJpaRepositories(basePackages = {"com.mudchobo.example.masterslave"})의 많은 설정을 추가해주었지만, Auto-Configuration의 설정 부분을 고려하여 불필요하다 판단하였습니다. ( 기본적으로 Qualifier를 활용한 다른 방식이 경우에는 직접 springContext의 bean을 가져오는 방식. CGLIB proxy생성이 필요 없기 때문에, 성능상의 이점을 위해 proxyBeanMethods=false 처리해준다. (실제 많은 많은 spring의 auto-configuration에서는 proxyBeanMethods=false로 설정되어있다.) @Configuration(proxyBeanMethods = false)
public class DataSourceConfig {
@Bean
@ConfigurationProperties(prefix = "spring.datasource.master")
public DataSource masterDataSource() {
return DataSourceBuilder.create().type(HikariDataSource.class).build();
}
@Bean
@ConfigurationProperties(prefix = "spring.datasource.slave")
public DataSource slaveDataSource() {
return DataSourceBuilder.create().type(HikariDataSource.class).build();
}
@Bean
public DataSource routingDataSource(@Qualifier("masterDataSource") DataSource masterDataSource,
@Qualifier("slaveDataSource") DataSource slaveDataSource) {
var routingDataSource = new ReplicationRoutingDataSource();
var dataSourceMap = new HashMap<>();
dataSourceMap.put("master", masterDataSource);
dataSourceMap.put("slave", slaveDataSource);
routingDataSource.setTargetDataSources(dataSourceMap);
routingDataSource.setDefaultTargetDataSource(masterDataSource);
return routingDataSource;
}
@Bean
@Primary
public DataSource dataSource(@Qualifier("routingDataSource") DataSource routingDataSource) {
return new LazyConnectionDataSourceProxy(routingDataSource);
}
}참고 |
|
|
|
WARN 21-10-06 20:59:48 [AnnotationConfigServletWebServerApplicationContext:591] - Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'flywayInitializer' defined in class path resource [org/springframework/boot/autoconfigure/flyway/FlywayAutoConfiguration$FlywayConfiguration.class]: Unsatisfied dependency expressed through method 'flywayInitializer' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'flyway' defined in class path resource [org/springframework/boot/autoconfigure/flyway/FlywayAutoConfiguration$FlywayConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.flywaydb.core.Flyway]: Factory method 'flyway' threw exception; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'dataSource' defined in class path resource [mine/is/gpu/config/DataSourceConfig.class]: Unsatisfied dependency expressed through method 'dataSource' parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'routingDataSource' defined in class path resource [mine/is/gpu/config/DataSourceConfig.class]: Unsatisfied dependency expressed through method 'routingDataSource' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'masterDataSource' defined in class path resource [mine/is/gpu/config/DataSourceConfig.class]: Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.boot.autoconfigure.jdbc.DataSourceInitializerInvoker': Invocation of init method failed; nested exception is org.springframework.beans.factory.BeanCurrentlyInCreationException: Error creating bean with name 'dataSource': Requested bean is currently in creation: Is there an unresolvable circular reference? |
@Profile("prod|was1|was2")
@Configuration(proxyBeanMethods = false)
@EnableAutoConfiguration(exclude = {DataSourceAutoConfiguration.class})
public class DataSourceConfig {
보다 이를 구조적으로 이해했으면, 최선의 방법을 사용했겠지만, 지금의 수준에서는 Circular 의존을 명확하게 이해하지는 못하겠음. 참고 자료Remember a Spring Boot multi-data source circular reference problem |
|
실제 dev 서버로 올리고 작업했을 때, insert, select query 모두 slave db를 찌르는 문제 발생.
|
|
순환 의존을 막기 위해서 @EnableAutoConfiguration(exclude = {DataSourceAutoConfiguration.class}) 이 설정이 필요했군요. |
public class ReplicationRoutingDataSource extends AbstractRoutingDataSource {
private static final Logger logger = LoggerFactory.getLogger(ReplicationRoutingDataSource.class);
public static final String DATASOURCE_KEY_MASTER = "master";
public static final String DATASOURCE_KEY_SLAVE = "slave";
@Override
protected Object determineCurrentLookupKey() {
boolean isReadOnly = TransactionSynchronizationManager.isCurrentTransactionReadOnly();
logger.info("This Transaction is " + isReadOnly);
if (isReadOnly) {
return DATASOURCE_KEY_SLAVE;
}
return DATASOURCE_KEY_MASTER;
}
}로깅을 진행했을 때, |
|
Job을 Post하는 부분의 Transaction이 ReadOnly지 확인 필요 |
|
하나의 api콜이 여러개의
|
|
혹시 |
이 부분도 혹시 몰라서 지금은 넣은 상태입니다! 근데, 안돼..
|
|
JPA의 default 세팅으로는 하나의 응답이나, View의 렌더링되기 까지, 영속성 컨텍스트가 유지된다. api별로 Master, Slave 의 요청을 결정하는 것 vs Transaction 별로 Master, Slave의 요청을 결정하는 것. 우선 지금의 경우 Transaction 별로 진행. 만약 1번의 방법을 사용한다면 어떻게 방식으로 사용할 수 있을까 의문이다 |
|
[master-db] 정상적으로 master에 쓰기작업이 이뤄지면 slave-db에 적용되는 부분 확인 |
DB 쿼리 이력 갯수 확인
|
@Configuration
@EnableAutoConfiguration(exclude = {DataSourceAutoConfiguration.class})
@EnableTransactionManagement
public class DataSourceConfig {
private final JpaProperties jpaProperties;
public DataSourceConfig(JpaProperties jpaProperties) {
this.jpaProperties = jpaProperties;
}
@Bean
@ConfigurationProperties(prefix = "spring.datasource.master")
public DataSource masterDataSource() {
return DataSourceBuilder.create().type(HikariDataSource.class).build();
}
@Bean
@ConfigurationProperties(prefix = "spring.datasource.slave")
public DataSource slaveDataSource() {
return DataSourceBuilder.create().type(HikariDataSource.class).build();
}
@Bean
public DataSource routingDataSource() {
ReplicationRoutingDataSource routingDataSource = new ReplicationRoutingDataSource();
HashMap<Object, Object> sources = new HashMap<>();
DataSource masterDataSource = masterDataSource();
sources.put(DATASOURCE_KEY_MASTER, masterDataSource);
sources.put(DATASOURCE_KEY_SLAVE, slaveDataSource());
routingDataSource.setTargetDataSources(sources);
routingDataSource.setDefaultTargetDataSource(masterDataSource);
return routingDataSource;
}
@Bean
public DataSource dataSource() {
return new LazyConnectionDataSourceProxy(routingDataSource());
}
@Bean
public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
EntityManagerFactoryBuilder entityManagerFactoryBuilder = createEntityManagerFactoryBuilder(jpaProperties);
return entityManagerFactoryBuilder.dataSource(dataSource()).packages("com.example.dbreplication").build();
}
private EntityManagerFactoryBuilder createEntityManagerFactoryBuilder(JpaProperties jpaProperties) {
AbstractJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
return new EntityManagerFactoryBuilder(vendorAdapter, jpaProperties.getProperties(), null);
}
@Bean
public PlatformTransactionManager transactionManager(EntityManagerFactory entityManagerFactory) {
JpaTransactionManager tm = new JpaTransactionManager();
tm.setEntityManagerFactory(entityManagerFactory);
return tm;
}
}왜 이런 방식으로 했을 때에는, 그건 바로 아래의 @Configuration(proxyBeanMethods = false)
@EnableConfigurationProperties(HibernateProperties.class)
@ConditionalOnSingleCandidate(DataSource.class)
class HibernateJpaConfiguration extends JpaBaseConfiguration {
}DataSource의 SinglaeCandidate으로 정의될 때에만, HibernateJpaConfiguration의 autoConfiguration 설정이 실행된다. 즉, DataSource의 Candidate가 설정되지 않은 위의 설정은 HibernateJpaConfiguration가 아예 실행되지 않는다. -> 이 부모클래스인 JpaBaseConfiguration의 설정들도 모두 실행되지 않는다. OpenEntityManagerInViewInterceptor 또한 설정이되지 않는 것이다! |
|
Provide support for auto-configuring multiple datasources Flyway circle에 관한 생각DataSourceInitializerInvoker는 dataSource를 필요로함.
-> Master에 적용하면 Slave에도 반영되는 부분 확인. 하지만, 안정적인 시스템을 위해서는 Application이 뜨는 시점에서 모든 DB에 migration validate를 진행해도 좋을 듯 하다. |
이슈 설명
DB 가용성 증대와 단일 장애점 해소를 위한 Replication 도입
The text was updated successfully, but these errors were encountered: