[SpringBoot] SpringBoot-Tomcat GracefulShutdown 구현

ㅁ SpringBoot 2.3 이전 버젼에서 graceful shutdown 구현

import org.apache.catalina.connector.Connector;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.web.embedded.tomcat.TomcatConnectorCustomizer;
import org.springframework.context.ApplicationListener;
import org.springframework.context.event.ContextClosedEvent;

import java.util.concurrent.Executor;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

public class GracefulShutdown implements TomcatConnectorCustomizer, ApplicationListener<ContextClosedEvent> {

    private static final Logger log = LoggerFactory.getLogger(GracefulShutdown.class);

    private static final int TIMEOUT = 30;

    private volatile Connector connector;

    @Override
    public void customize(Connector connector) {
        this.connector = connector;
    }

    @Override
    public void onApplicationEvent(ContextClosedEvent event) {
        this.connector.pause(); // 외부의 요청을 더 이상 받지 않도록 한다.
        Executor executor = this.connector.getProtocolHandler().getExecutor();
        if (executor instanceof ThreadPoolExecutor) {
            try {
            	// 기존 작업들이 정상적으로 종료되었는지 30초 동안 체크하낟.
                ThreadPoolExecutor threadPoolExecutor = (ThreadPoolExecutor) executor;
                threadPoolExecutor.shutdown();
                if (!threadPoolExecutor.awaitTermination(TIMEOUT, TimeUnit.SECONDS)) {
                    log.warn("Tomcat thread pool did not shut down gracefully within "
                            + TIMEOUT + " seconds. Proceeding with forceful shutdown");

                    threadPoolExecutor.shutdownNow();

                    if (!threadPoolExecutor.awaitTermination(TIMEOUT, TimeUnit.SECONDS)) {
                        log.error("Tomcat thread pool did not terminate");
                    }
                }
            } catch (InterruptedException ex) {
                Thread.currentThread().interrupt();
            }
        }
    }

}

 

@Bean
public GracefulShutdown gracefulShutdown() {
    return new GracefulShutdown();
}

@Bean
public ConfigurableServletWebServerFactory webServerFactory(final GracefulShutdown gracefulShutdown) {
    TomcatServletWebServerFactory factory = new TomcatServletWebServerFactory();
    factory.addConnectorCustomizers(gracefulShutdown);
    return factory;
}

참조) https://blog.marcosbarbero.com/graceful-shutdown-spring-boot-apps/ 

 

 

 

Spring - Tomcat에서의 Graceful Shutdown 관련 레퍼런스는 많았다. 하지만 Spring - Netty로 Graceful Shutdown을 적용한 레퍼런스는 거의 없었다.