fixes #141 add maxRetries to the configuration for lambda invoker

lambda-invoker/src/main/java/com/networknt/aws/lambda/LambdaFunctionHandler.java

@@ -23,6 +23,7 @@
 import software.amazon.awssdk.http.async.SdkAsyncHttpClient;
 import software.amazon.awssdk.http.nio.netty.NettyNioAsyncHttpClient;
 import software.amazon.awssdk.regions.Region;
+import software.amazon.awssdk.retries.DefaultRetryStrategy;
 import software.amazon.awssdk.services.lambda.LambdaAsyncClient;
 import software.amazon.awssdk.services.lambda.model.InvokeRequest;
 
@@ -58,6 +59,14 @@ public LambdaFunctionHandler() {
                 .apiCallAttemptTimeout(Duration.ofSeconds(config.getApiCallAttemptTimeout()))
                 .build();
 
+        if(config.getMaxRetries() > 0) {
+            overrideConfig = overrideConfig.toBuilder()
+                    .retryStrategy(DefaultRetryStrategy.standardStrategyBuilder()
+                            .maxAttempts(config.getMaxRetries())
+                            .build())
+                    .build();
+        }
+
         var builder = LambdaAsyncClient.builder().region(Region.of(config.getRegion()))
                 .httpClient(asyncHttpClient)
                 .overrideConfiguration(overrideConfig);

lambda-invoker/src/main/java/com/networknt/aws/lambda/LambdaInvokerConfig.java

@@ -22,6 +22,7 @@ public class LambdaInvokerConfig {
     private static final String FUNCTIONS = "functions";
     private static final String METRICS_INJECTION = "metricsInjection";
     private static final String METRICS_NAME = "metricsName";
+    private static final String MAX_RETRIES = "maxRetries";
     private static final String MAX_CONCURRENCY = "maxConcurrency";
     private static final String MAX_PENDING_CONNECTION_ACQUIRES = "maxPendingConnectionAcquires";
     private static final String CONNECTION_ACQUISITION_TIMEOUT = "connectionAcquisitionTimeout";
@@ -34,6 +35,7 @@ public class LambdaInvokerConfig {
     private Map<String, String> functions;
     private boolean metricsInjection;
     private String metricsName;
+    private int maxRetries;
     private int maxConcurrency;
     private int maxPendingConnectionAcquires;
     private int connectionAcquisitionTimeout;
@@ -102,6 +104,14 @@ public void setMetricsName(String metricsName) {
         this.metricsName = metricsName;
     }
 
+    public int getMaxRetries() {
+        return maxRetries;
+    }
+
+    public void setMaxRetries(int maxRetries) {
+        this.maxRetries = maxRetries;
+    }
+
     public int getMaxConcurrency() {
         return maxConcurrency;
     }
@@ -192,6 +202,10 @@ private void setConfigData() {
         if(object != null ) {
             metricsName = (String)object;
         }
+        object = mappedConfig.get(MAX_RETRIES);
+        if (object != null) {
+            maxRetries = Config.loadIntegerValue(MAX_RETRIES, object);
+        }
         object = mappedConfig.get(MAX_CONCURRENCY);
         if (object != null) {
             maxConcurrency = Config.loadIntegerValue(MAX_CONCURRENCY, object);

lambda-invoker/src/main/resources/config/lambda-invoker.yml

@@ -7,6 +7,8 @@ endpointOverride: ${lambda-invoker.endpointOverride:}
 apiCallTimeout: ${lambda-invoker.apiCallTimeout:60000}
 # Api call attempt timeout in milliseconds. This sets the amount of time for each individual attempt.
 apiCallAttemptTimeout: ${lambda-invoker.apiCallAttemptTimeout:20000}
+# The maximum number of retries for the Lambda function invocation. Default is 3. Set to 0 to disable retries.
+maxRetries: ${lambda-invoker.maxRetries:3}
 # The maximum number of concurrent requests that can be made to Lambda. Default is 50.
 maxConcurrency: ${lambda-invoker.maxConcurrency:50}
 # The maximum number of pending acquires allowed. Default is 10000.