Deprecate asyncInit & account for other initialization types

aws-serverless-java-container-core/src/main/java/com/amazonaws/serverless/proxy/AsyncInitializationWrapper.java

@@ -38,8 +38,13 @@
  * seconds has already been used up.
  */
 public class AsyncInitializationWrapper extends InitializationWrapper {
+
     private static final int DEFAULT_INIT_GRACE_TIME_MS = 150;
     private static final String INIT_GRACE_TIME_ENVIRONMENT_VARIABLE_NAME = "AWS_SERVERLESS_JAVA_CONTAINER_INIT_GRACE_TIME";
+    private static final String INITIALIZATION_TYPE_ENVIRONMENT_VARIABLE_NAME = "AWS_LAMBDA_INITIALIZATION_TYPE";
+    private static final String INITIALIZATION_TYPE_ON_DEMAND = "on-demand";
+    private static final String INITIALIZATION_TYPE = System.getenv().getOrDefault(INITIALIZATION_TYPE_ENVIRONMENT_VARIABLE_NAME,INITIALIZATION_TYPE_ON_DEMAND);
+    private static final boolean ASYNC_INIT_DISABLED = !INITIALIZATION_TYPE.equals(INITIALIZATION_TYPE_ON_DEMAND);
     private static final int INIT_GRACE_TIME_MS = Integer.parseInt(System.getenv().getOrDefault(
             INIT_GRACE_TIME_ENVIRONMENT_VARIABLE_NAME, Integer.toString(DEFAULT_INIT_GRACE_TIME_MS)));
     private static final int LAMBDA_MAX_INIT_TIME_MS = 10_000;
@@ -48,6 +53,7 @@ public class AsyncInitializationWrapper extends InitializationWrapper {
     private final long actualStartTime;
     private Logger log = LoggerFactory.getLogger(AsyncInitializationWrapper.class);
 
+
     /**
      * Creates a new instance of the async initializer.
      * @param startTime The epoch ms start time of the Lambda function, this should be measured as close as possible to
@@ -67,6 +73,11 @@ public AsyncInitializationWrapper() {
 
     @Override
     public void start(LambdaContainerHandler handler) throws ContainerInitializationException {
+        if(ASYNC_INIT_DISABLED){
+            log.info("Async init disabled due to \"{}\" initialization", INITIALIZATION_TYPE);
+            super.start(handler);
+            return;
+        }
         initializationLatch = new CountDownLatch(1);
         AsyncInitializer initializer = new AsyncInitializer(initializationLatch, handler);
         Thread initThread = new Thread(initializer);
@@ -96,6 +107,9 @@ public long getActualStartTimeMs() {
 
     @Override
     public CountDownLatch getInitializationLatch() {
+        if(ASYNC_INIT_DISABLED){
+            return super.getInitializationLatch();
+        }
         return initializationLatch;
     }
 

aws-serverless-java-container-core/src/main/java/com/amazonaws/serverless/proxy/internal/servlet/ServletLambdaContainerHandlerBuilder.java

@@ -92,7 +92,7 @@ protected void validate() throws ContainerInitializationException {
      * @return A populated builder
      */
     public Builder defaultProxy() {
-        initializationWrapper(new InitializationWrapper())
+        initializationWrapper(new AsyncInitializationWrapper())
                 .requestReader((RequestReader<RequestType, ContainerRequestType>) new AwsProxyHttpServletRequestReader())
                 .responseWriter((ResponseWriter<AwsHttpServletResponse, ResponseType>) new AwsProxyHttpServletResponseWriter())
                 .securityContextWriter((SecurityContextWriter<RequestType>) new AwsProxySecurityContextWriter())
@@ -108,7 +108,7 @@ public Builder defaultProxy() {
      * @return A populated builder
      */
     public Builder defaultHttpApiV2Proxy() {
-        initializationWrapper(new InitializationWrapper())
+        initializationWrapper(new AsyncInitializationWrapper())
                 .requestReader((RequestReader<RequestType, ContainerRequestType>) new AwsHttpApiV2HttpServletRequestReader())
                 .responseWriter((ResponseWriter<AwsHttpServletResponse, ResponseType>) new AwsProxyHttpServletResponseWriter(true))
                 .securityContextWriter((SecurityContextWriter<RequestType>) new AwsHttpApiV2SecurityContextWriter())
@@ -165,7 +165,7 @@ public Builder responseTypeClass(Class<ResponseType> responseType) {
     /**
      * Uses an async initializer with the given start time to calculate the 10 seconds timeout.
      *
-     * @deprecated As of release 1.5 this method is deprecated in favor of the parameters-less one {@link ServletLambdaContainerHandlerBuilder#asyncInit()}.
+     * @deprecated As of release 2.1 this method is deprecated. Initializer is always async if running in on-demand.
      * @param actualStartTime An epoch in milliseconds that should be used to calculate the 10 seconds timeout since the start of the application
      * @return A builder configured to use the async initializer
      */
@@ -178,6 +178,7 @@ public Builder asyncInit(long actualStartTime) {
     /**
      * Uses a new {@link AsyncInitializationWrapper} with the no-parameter constructor that takes the actual JVM
      * start time
+     * @deprecated As of release 2.1 this method is deprecated. Initializer is always async if running in on-demand.
      * @return A builder configured to use an async initializer
      */
     public Builder asyncInit() {

aws-serverless-java-container-spring/src/test/java/com/amazonaws/serverless/proxy/spring/springslowapp/LambdaHandler.java

@@ -18,7 +18,6 @@ public LambdaHandler() throws ContainerInitializationException {
         long startTime = Instant.now().toEpochMilli();
         handler = new SpringProxyHandlerBuilder<AwsProxyRequest>()
                 .defaultProxy()
-                .asyncInit()
                 .configurationClasses(SlowAppConfig.class)
                 .buildAndInitialize();
         constructorTime = Instant.now().toEpochMilli() - startTime;

aws-serverless-java-container-springboot3/src/test/java/com/amazonaws/serverless/proxy/spring/slowapp/LambdaHandler.java

@@ -21,7 +21,6 @@ public LambdaHandler() {
             System.out.println("startCall: " + startTime);
             handler = new SpringBootProxyHandlerBuilder<AwsProxyRequest>()
                     .defaultProxy()
-                    .asyncInit()
                     .springBootApplication(SlowTestApplication.class)
                     .buildAndInitialize();
             constructorTime = Instant.now().toEpochMilli() - startTime;

aws-serverless-springboot3-archetype/src/main/resources/archetype-resources/src/main/java/StreamLambdaHandler.java

@@ -18,12 +18,6 @@ public class StreamLambdaHandler implements RequestStreamHandler {
     static {
         try {
             handler = SpringBootLambdaContainerHandler.getAwsProxyHandler(Application.class);
-            // For applications that take longer than 10 seconds to start, use the async builder:
-            // handler = new SpringBootProxyHandlerBuilder<AwsProxyRequest>()
-            //                    .defaultProxy()
-            //                    .asyncInit()
-            //                    .springBootApplication(Application.class)
-            //                    .buildAndInitialize();
         } catch (ContainerInitializationException e) {
             // if we fail here. We re-throw the exception to force another cold start
             e.printStackTrace();

samples/springboot3/pet-store/src/main/java/com/amazonaws/serverless/sample/springboot3/StreamLambdaHandler.java

@@ -25,13 +25,6 @@ public class StreamLambdaHandler implements RequestStreamHandler {
         try {
             handler = SpringBootLambdaContainerHandler.getAwsProxyHandler(Application.class);
 
-            // For applications that take longer than 10 seconds to start, use the async builder:
-            // handler = new SpringBootProxyHandlerBuilder<AwsProxyRequest>()
-            //                    .defaultProxy()
-            //                    .asyncInit()
-            //                    .springBootApplication(Application.class)
-            //                    .buildAndInitialize();
-
             // we use the onStartup method of the handler to register our custom filter
             handler.onStartup(servletContext -> {
                 FilterRegistration.Dynamic registration = servletContext.addFilter("CognitoIdentityFilter", CognitoIdentityFilter.class);