feat: 키워드 알림 스레드 분리

src/main/java/in/koreatech/koin/domain/notification/eventlistener/ArticleKeywordEventListener.java

@@ -13,6 +13,7 @@
 import java.util.stream.Collectors;
 
 import org.springframework.context.annotation.Profile;
+import org.springframework.scheduling.annotation.Async;
 import org.springframework.stereotype.Component;
 import org.springframework.util.StringUtils;
 import org.springframework.transaction.event.TransactionalEventListener;
@@ -42,6 +43,7 @@ public class ArticleKeywordEventListener { // TODO : 리팩터링 필요 (비즈
     private final KeywordService keywordService;
     private final ArticleRepository articleRepository;
 
+    @Async
     @TransactionalEventListener
     public void onKeywordRequest(ArticleKeywordEvent event) {
         Map<Integer, String> matchedKeywordByUserId = event.matchedKeywordByUserId();

src/main/java/in/koreatech/koin/global/config/AsyncConfig.java

@@ -1,11 +1,14 @@
 package in.koreatech.koin.global.config;
 
+import static java.util.concurrent.ThreadPoolExecutor.CallerRunsPolicy;
+
 import java.util.concurrent.Executor;
 
 import org.springframework.aop.interceptor.AsyncUncaughtExceptionHandler;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.scheduling.annotation.AsyncConfigurer;
 import org.springframework.scheduling.annotation.EnableAsync;
+import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
 
 import lombok.extern.slf4j.Slf4j;
 
@@ -16,7 +19,14 @@ public class AsyncConfig implements AsyncConfigurer {
 
     @Override
     public Executor getAsyncExecutor() {
-        return null;
+        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
+        executor.setCorePoolSize(2);
+        executor.setMaxPoolSize(5);
+        executor.setQueueCapacity(20);
+        executor.setThreadNamePrefix("AsyncExecutor-");
+        executor.setRejectedExecutionHandler(new CallerRunsPolicy());
+        executor.initialize();
+        return executor;
     }
 
     @Override