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4.1.1.2 Spring Boot에서 OCI Cache with Redis 사용하기

Spring Boot에서는 캐쉬를 설정할 수 있고, 캐쉬 서버로 Redis를 많이 사용합니다. OCI Cache with Redis로 만든 Redis 클러스터도 Spring Boot, Redis 코드에서 잘 연결되는 지 확인해 봅니다.

예제 Caching Data with Spring으로 기본 캐쉬 따라하기

Caching Data with Spring을 따라 순서대로 진행합니다. ‘OCI Cache with Redis를 캐쉬 서버로 연동’ 전까지는 해당 링크 내용과 동일합니다.

• 소소를 Download 받아, 압축해제하거나, Git 명령(git clone https://github.com/spring-guides/gs-caching.git)을 사용하여 복제합니다.
• cd gs-caching/initial

캐쉬설정하기 전

1. 소스를 빌드하고 실행합니다.

   ./mvnw clean package
   java -jar target/caching-initial-0.0.1-SNAPSHOT.jar
   

2. 애플리케이션을 실행합니다. 각 조회가 매번 3초 가량 걸리는 것을 볼 수 있습니다.

   2023-11-16T11:34:38.459+09:00  INFO 4132 --- [           main] com.example.caching.AppRunner            : .... Fetching books
   2023-11-16T11:34:41.463+09:00  INFO 4132 --- [           main] com.example.caching.AppRunner            : isbn-1234 -->Book{isbn='isbn-1234', title='Some book'}
   2023-11-16T11:34:44.465+09:00  INFO 4132 --- [           main] com.example.caching.AppRunner            : isbn-1234 -->Book{isbn='isbn-1234', title='Some book'}
   2023-11-16T11:34:47.468+09:00  INFO 4132 --- [           main] com.example.caching.AppRunner            : isbn-1234 -->Book{isbn='isbn-1234', title='Some book'}
   

Enable caching

1. src/main/java/com/example/caching/SimpleBookRepository.java 에 @Cacheable("books")를 추가하여, getByIsbn() 메서드의 결과를 books 캐쉬에 캐쉬하도록 설정합니다.

   package com.example.caching;
   
   import org.springframework.cache.annotation.Cacheable;
   import org.springframework.stereotype.Component;
   
   @Component
   public class SimpleBookRepository implements BookRepository {
   
     @Override
     @Cacheable("books")
     public Book getByIsbn(String isbn) {
       simulateSlowService();
       return new Book(isbn, "Some book");
     }
   
     // Don't do this at home
     private void simulateSlowService() {
       try {
         long time = 3000L;
         Thread.sleep(time);
       } catch (InterruptedException e) {
         throw new IllegalStateException(e);
       }
     }
   
   }
   

2. src/main/java/com/example/caching/CachingApplication.java 에 @EnableCaching annotation을 추가합니다.

   • 캐쉬 라이브러리를 별도로 지정하지 않으면, 디폴트로 ConcurrentHashMap을 사용합니다.

   package com.example.caching;
   
   import org.springframework.boot.SpringApplication;
   import org.springframework.boot.autoconfigure.SpringBootApplication;
   import org.springframework.cache.annotation.EnableCaching;
   
   @SpringBootApplication
   @EnableCaching
   public class CachingApplication {
   
     public static void main(String[] args) {
       SpringApplication.run(CachingApplication.class, args);
     }
   
   }
   

3. 소스를 빌드하고 실행합니다.

   ./mvnw clean package
   java -jar target/caching-initial-0.0.1-SNAPSHOT.jar
   

4. 처음 조회가 3초 가량 걸리고, 이후 2번은 캐쉬 데이터를 사용하여, 바로 응답한 것을 볼 수 있습니다.

   2023-11-16T11:53:55.346+09:00  INFO 5782 --- [           main] com.example.caching.AppRunner            : .... Fetching books
   2023-11-16T11:53:58.351+09:00  INFO 5782 --- [           main] com.example.caching.AppRunner            : isbn-1234 -->Book{isbn='isbn-1234', title='Some book'}
   2023-11-16T11:53:58.355+09:00  INFO 5782 --- [           main] com.example.caching.AppRunner            : isbn-1234 -->Book{isbn='isbn-1234', title='Some book'}
   2023-11-16T11:53:58.356+09:00  INFO 5782 --- [           main] com.example.caching.AppRunner            : isbn-1234 -->Book{isbn='isbn-1234', title='Some book'}
   

OCI Cache with Redis를 캐쉬 서버로 연동하기

1. dependency에 redis를 추가합니다.

   • Maven 기준 pom.xml에 다음 추가

   		<dependency>
   			<groupId>org.springframework.boot</groupId>
   			<artifactId>spring-boot-starter-data-redis</artifactId>
   		</dependency>	
   

2. src/main/application.properties 파일을 생성하고 다음 항목을 추가합니다.

   • 아래 host, port는 개발환경을 기준으로 앞선 실습에서의 Bastion 서비스를 통해 포트포워딩으로 연동하는 예시입니다.

   spring.redis.host=localhost
   spring.redis.port=6379
   spring.redis.ssl=true
   

3. Redis 설정을 위한 Config 클래스 파일( src/main/java/com/example/caching/RedisConfig.java)을 만듭니다.

   • lettuce 라이브러리를 사용하는 예시입니다.
     • redis-cli에서 --tls 옵션을 사용한 것 처럼 lettuceClientConfigurationBuilder.useSsl().disablePeerVerification()을 꼭 추가합니다.
     • application.properties에 값을 사용하여 host, port 값과 ssl 설정여부 설정하는 예시입니다.

   package com.example.caching;
   
   import org.springframework.context.annotation.Configuration;
   import org.springframework.context.annotation.Bean;
   
   import org.springframework.beans.factory.annotation.Value;
   
   import org.springframework.data.redis.connection.RedisConnectionFactory;
   import org.springframework.data.redis.connection.RedisStandaloneConfiguration;
   
   import org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory;
   import org.springframework.data.redis.connection.lettuce.LettuceClientConfiguration;
   
   import org.springframework.data.redis.connection.RedisNode;
   
   @Configuration
   public class RedisConfig {
   
       @Value("${spring.redis.host}")
       private String host;
   
       @Value("${spring.redis.port}")
       private int port;
   
       @Value("${spring.redis.ssl}")
       private boolean ssl;
   
       @Bean
       public RedisConnectionFactory redisConnectionFactory() {
           final RedisNode redisNode = RedisNode.newRedisNode()
                   .listeningAt(host, port)
                   .build();
   
           // Connecting as a Standalone Redis server
           final RedisStandaloneConfiguration redisStandaloneConfiguration = new RedisStandaloneConfiguration();
           redisStandaloneConfiguration.setHostName(host);
           redisStandaloneConfiguration.setPort(port);
   
           final LettuceClientConfiguration.LettuceClientConfigurationBuilder lettuceClientConfigurationBuilder =
                   LettuceClientConfiguration.builder();
   
           if (ssl) {
               lettuceClientConfigurationBuilder.useSsl().disablePeerVerification();
           }
   
           final LettuceClientConfiguration lettuceClientConfiguration = lettuceClientConfigurationBuilder.build();
   
           return new LettuceConnectionFactory(redisStandaloneConfiguration, lettuceClientConfiguration);
       }    
   
   }
   

4. 캐쉬되는 데이터 모델( src/main/java/com/example/caching/Book.java)을 Serializable 하도록 설정합니다.

   package com.example.caching;
   
   import java.io.Serializable;
   
   public class Book implements Serializable {
   
   	...
   
   }
   

5. 소스를 빌드하고 실행합니다.

   ./mvnw clean package
   java -jar target/caching-initial-0.0.1-SNAPSHOT.jar
   

6. 처음 조회가 3초 가량 걸리고, 이후 2번은 빠르게 실행되는 것을 볼 수 있습니다. 결과는 앞선 기본 ConcurrentHashMap를 저장소로 사용할 때랑 동일합니다.

   2023-11-16T12:53:16.367+09:00  INFO 12783 --- [           main] com.example.caching.AppRunner            : .... Fetching books
   2023-11-16T12:53:20.008+09:00  INFO 12783 --- [           main] com.example.caching.AppRunner            : isbn-1234 -->Book{isbn='isbn-1234', title='Some book'}
   2023-11-16T12:53:20.058+09:00  INFO 12783 --- [           main] com.example.caching.AppRunner            : isbn-1234 -->Book{isbn='isbn-1234', title='Some book'}
   2023-11-16T12:53:20.100+09:00  INFO 12783 --- [           main] com.example.caching.AppRunner            : isbn-1234 -->Book{isbn='isbn-1234', title='Some book'}
   

redis-cli로 Redis 클러스터에서 결과확인

1. redis-cli로 포트 포워딩된 localhost, 6379 포트로 접속합니다.

2. keys, get 명령으로 데이터가 들어간 것을 확인 할 수 있습니다.

   $ redis-cli --tls -h localhost
   localhost:6379> keys *
   1) "books::isbn-1234"
   localhost:6379> get books::isbn-1234
   "\xac\xed\x00\x05sr\x00\x18com.example.caching.Book\x81\xa5yv\x90|\xa3\xe8\x02\x00\x02L\x00\x04isbnt\x00\x12Ljava/lang/String;L\x00\x05titleq\x00~\x00\x01xpt\x00\tisbn-1234t\x00\tSome book"
   localhost:6379>
   

추가 테스트

1. 추가 테스트를 위해 src/main/java/com/example/caching/AppRunner.java 파일을 수정합니다.

   package com.example.caching;
   
   import org.slf4j.Logger;
   import org.slf4j.LoggerFactory;
   import org.springframework.boot.CommandLineRunner;
   import org.springframework.stereotype.Component;
   
   @Component
   public class AppRunner implements CommandLineRunner {
   
     private static final Logger logger = LoggerFactory.getLogger(AppRunner.class);
   
     private final BookRepository bookRepository;
   
     public AppRunner(BookRepository bookRepository) {
       this.bookRepository = bookRepository;
     }
   
     @Override
     public void run(String... args) throws Exception {
       logger.info(".... Fetching books");
       logger.info("isbn-1234 -->" + bookRepository.getByIsbn("isbn-1234"));
       logger.info("isbn-4567 -->" + bookRepository.getByIsbn("isbn-4567"));
       logger.info("isbn-1234 -->" + bookRepository.getByIsbn("isbn-1234"));
       logger.info("isbn-4567 -->" + bookRepository.getByIsbn("isbn-4567"));
     }
   
   }
   

2. src/main/application.properties 파일에 다음 항목을 추가합니다.

   logging.level.org.springframework.cache=TRACE
   

3. 다시 빌드하고 실행합니다.

   ./mvnw clean package
   java -jar target/caching-initial-0.0.1-SNAPSHOT.jar
   

4. 실행 로그 확인

   • isbn-1234 조회: 두 번 모두 Cache entry for key 'isbn-1234' found in cache 'books' 와 같이 Cache Hit 되었습니다.
   • isbn-4567 조회:
     1. No cache entry for key 'isbn-4567' in cache(s) [books] - 첫번째는 Cache Miss
     2. Cache entry for key 'isbn-4567' found in cache 'books' - 두번째는 Cache Hit

   2023-11-16T13:06:42.373+09:00  INFO 34105 --- [           main] com.example.caching.AppRunner            : .... Fetching books
   2023-11-16T13:06:42.375+09:00 TRACE 34105 --- [           main] o.s.cache.interceptor.CacheInterceptor   : Computed cache key 'isbn-1234' for operation Builder[public com.example.caching.Book com.example.caching.SimpleBookRepository.getByIsbn(java.lang.String)] caches=[books] | key='' | keyGenerator='' | cacheManager='' | cacheResolver='' | condition='' | unless='' | sync='false'
   2023-11-16T13:06:42.890+09:00 TRACE 34105 --- [           main] o.s.cache.interceptor.CacheInterceptor   : Cache entry for key 'isbn-1234' found in cache 'books'
   2023-11-16T13:06:42.890+09:00  INFO 34105 --- [           main] com.example.caching.AppRunner            : isbn-1234 -->Book{isbn='isbn-1234', title='Some book'}
   
   2023-11-16T13:06:42.890+09:00 TRACE 34105 --- [           main] o.s.cache.interceptor.CacheInterceptor   : Computed cache key 'isbn-4567' for operation Builder[public com.example.caching.Book com.example.caching.SimpleBookRepository.getByIsbn(java.lang.String)] caches=[books] | key='' | keyGenerator='' | cacheManager='' | cacheResolver='' | condition='' | unless='' | sync='false'
   2023-11-16T13:06:42.932+09:00 TRACE 34105 --- [           main] o.s.cache.interceptor.CacheInterceptor   : No cache entry for key 'isbn-4567' in cache(s) [books]
   2023-11-16T13:06:42.932+09:00 TRACE 34105 --- [           main] o.s.cache.interceptor.CacheInterceptor   : Computed cache key 'isbn-4567' for operation Builder[public com.example.caching.Book com.example.caching.SimpleBookRepository.getByIsbn(java.lang.String)] caches=[books] | key='' | keyGenerator='' | cacheManager='' | cacheResolver='' | condition='' | unless='' | sync='false'
   2023-11-16T13:06:45.996+09:00  INFO 34105 --- [           main] com.example.caching.AppRunner            : isbn-4567 -->Book{isbn='isbn-4567', title='Some book'}
   
   2023-11-16T13:06:45.997+09:00 TRACE 34105 --- [           main] o.s.cache.interceptor.CacheInterceptor   : Computed cache key 'isbn-1234' for operation Builder[public com.example.caching.Book com.example.caching.SimpleBookRepository.getByIsbn(java.lang.String)] caches=[books] | key='' | keyGenerator='' | cacheManager='' | cacheResolver='' | condition='' | unless='' | sync='false'
   2023-11-16T13:06:46.042+09:00 TRACE 34105 --- [           main] o.s.cache.interceptor.CacheInterceptor   : Cache entry for key 'isbn-1234' found in cache 'books'
   2023-11-16T13:06:46.043+09:00  INFO 34105 --- [           main] com.example.caching.AppRunner            : isbn-1234 -->Book{isbn='isbn-1234', title='Some book'}
   
   2023-11-16T13:06:46.043+09:00 TRACE 34105 --- [           main] o.s.cache.interceptor.CacheInterceptor   : Computed cache key 'isbn-4567' for operation Builder[public com.example.caching.Book com.example.caching.SimpleBookRepository.getByIsbn(java.lang.String)] caches=[books] | key='' | keyGenerator='' | cacheManager='' | cacheResolver='' | condition='' | unless='' | sync='false'
   2023-11-16T13:06:46.088+09:00 TRACE 34105 --- [           main] o.s.cache.interceptor.CacheInterceptor   : Cache entry for key 'isbn-4567' found in cache 'books'
   2023-11-16T13:06:46.088+09:00  INFO 34105 --- [           main] com.example.caching.AppRunner            : isbn-4567 -->Book{isbn='isbn-4567', title='Some book'}
   

5. redis-cli로 다시 조회해 보면 새로 추가한 isbn-4567도 들어가 있는 것을 볼 수 있습니다.

   $ redis-cli --tls -h localhost
   localhost:6379> keys *
   1) "books::isbn-4567"
   2) "books::isbn-1234"
   localhost:6379>
   

참고

• https://spring.io/guides/gs/caching/
• https://www.bezkoder.com/spring-boot-redis-cache-example/