[FIXED] Spring Boot Lambda Startup multiple times at the cold start

Issue

I'm writing small Data downloading service function using Spring Boot 2.7. I deployed it in the AWS lambda function. At the cold starting each time it initializes twice as shown in the image below.

src="https://i.stack.imgur.com/qZK0M.png" alt="enter image description here" />

Here is the lambderHandler.java

public class LambdaHandler implements RequestHandler<SQSEvent, String> {
    
        private static final ApplicationContext applicationContext = SpringApplication.run(DataDownloaderService.class);
    
        @Override
        public String handleRequest(SQSEvent event, Context context) {
            context.getLogger().log("Input: " + event);
            if (!event.getRecords().isEmpty()) {
                SQSEvent.SQSMessage firstRecord = event.getRecords().get(0);
                String eventBody = firstRecord.getBody();
                if (eventBody != null) {
                    ProductDownloadService productDownloadService = applicationContext.getBean(ProductDownloadServiceImpl.class);
                    try {
                        productDownloadService.downloadProductData(JsonUtil.getUserInfo(eventBody));
                        return "Successfully processed";
                    } catch (IOException e) {
                        return "Error in data downloading: " + e.getMessage();
                    }
                }
            }
            return "Data download not success";
        }
 }

Here is the DataDownloaderService.java

@SpringBootApplication
@ComponentScan(basePackages = {"com.test.*"})
@EntityScan(basePackages = {"com.test.*"})
public class DataDownloaderService {

}

Why spring boot lambda function initialize multiple times at the cold start? Did I have some misconfiguration here or is it a bug?

Solution

I found a workaround to fix this issue from here.

Here is the workaround for the above code.

public class LambdaHandler implements RequestHandler<SQSEvent, String> {

private ApplicationContext applicationContext;

/**
 * Entry point in the lambda function
 * @param event
 * @param context
 * @return
 */
@Override
public String handleRequest(SQSEvent event, Context context) {
    return initDataDownloaderService(event, context);
}

/**
 * initialize application context and Data downloader service
 *
 * @param event
 * @param context
 * @return
 */
private String initDataDownloaderService(SQSEvent event, Context context) {
    if (applicationContext == null) {
        applicationContext = SpringApplication.run(DataDownloaderService.class);
    }
    context.getLogger().log("Input: " + event);
    if (!event.getRecords().isEmpty()) {
        SQSEvent.SQSMessage firstRecord = event.getRecords().get(0);
        String eventBody = firstRecord.getBody();
        if (eventBody != null) {
            ProductDownloadService productDownloadService = applicationContext.getBean(ProductDownloadServiceImpl.class);
            try {
                productDownloadService.downloadProductData(JsonUtil.getUserInfo(eventBody));
                return "Successfully processed";
            } catch (IOException e) {
                return "Error in data downloading: " + e.getMessage();
            }
        }
    }
    return "Data download not success";
}

}

Answered By - Maneesha Randeniya
Answer Checked By - Marilyn (JavaFixing Volunteer)