fixes #139 add three connection related configuration properties

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

@@ -2,7 +2,6 @@
 
 import com.amazonaws.services.lambda.runtime.events.APIGatewayProxyRequestEvent;
 import com.amazonaws.services.lambda.runtime.events.APIGatewayProxyResponseEvent;
-import com.networknt.body.BodyHandler;
 import com.networknt.config.Config;
 import com.networknt.config.JsonMapper;
 import com.networknt.handler.Handler;
@@ -25,11 +24,7 @@
 import software.amazon.awssdk.http.nio.netty.NettyNioAsyncHttpClient;
 import software.amazon.awssdk.regions.Region;
 import software.amazon.awssdk.services.lambda.LambdaAsyncClient;
-import software.amazon.awssdk.services.lambda.LambdaClient;
-import software.amazon.awssdk.services.lambda.LambdaClientBuilder;
 import software.amazon.awssdk.services.lambda.model.InvokeRequest;
-import software.amazon.awssdk.services.lambda.model.InvokeResponse;
-import software.amazon.awssdk.services.lambda.model.LambdaException;
 
 import java.net.URI;
 import java.time.Duration;
@@ -54,6 +49,9 @@ public LambdaFunctionHandler() {
                 .readTimeout(Duration.ofMillis(config.getApiCallAttemptTimeout()))
                 .writeTimeout(Duration.ofMillis(config.getApiCallAttemptTimeout()))
                 .connectionTimeout(Duration.ofMillis(config.getApiCallAttemptTimeout()))
+                .maxConcurrency(config.getMaxConcurrency())
+                .maxPendingConnectionAcquires(config.getMaxPendingConnectionAcquires())
+                .connectionAcquisitionTimeout(Duration.ofSeconds(config.getConnectionAcquisitionTimeout()))
                 .build();
         ClientOverrideConfiguration overrideConfig = ClientOverrideConfiguration.builder()
                 .apiCallTimeout(Duration.ofMillis(config.getApiCallTimeout()))

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

@@ -22,6 +22,9 @@ 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_CONCURRENCY = "maxConcurrency";
+    private static final String MAX_PENDING_CONNECTION_ACQUIRES = "maxPendingConnectionAcquires";
+    private static final String CONNECTION_ACQUISITION_TIMEOUT = "connectionAcquisitionTimeout";
 
     private String region;
     private String endpointOverride;
@@ -31,6 +34,9 @@ public class LambdaInvokerConfig {
     private Map<String, String> functions;
     private boolean metricsInjection;
     private String metricsName;
+    private int maxConcurrency;
+    private int maxPendingConnectionAcquires;
+    private int connectionAcquisitionTimeout;
 
     public String getRegion() {
         return region;
@@ -96,6 +102,30 @@ public void setMetricsName(String metricsName) {
         this.metricsName = metricsName;
     }
 
+    public int getMaxConcurrency() {
+        return maxConcurrency;
+    }
+
+    public void setMaxConcurrency(int maxConcurrency) {
+        this.maxConcurrency = maxConcurrency;
+    }
+
+    public int getMaxPendingConnectionAcquires() {
+        return maxPendingConnectionAcquires;
+    }
+
+    public void setMaxPendingConnectionAcquires(int maxPendingConnectionAcquires) {
+        this.maxPendingConnectionAcquires = maxPendingConnectionAcquires;
+    }
+
+    public int getConnectionAcquisitionTimeout() {
+        return connectionAcquisitionTimeout;
+    }
+
+    public void setConnectionAcquisitionTimeout(int connectionAcquisitionTimeout) {
+        this.connectionAcquisitionTimeout = connectionAcquisitionTimeout;
+    }
+
     private final Config config;
     private Map<String, Object> mappedConfig;
 
@@ -114,6 +144,7 @@ private LambdaInvokerConfig(String configName) {
         setConfigData();
         setConfigMap();
     }
+
     public static LambdaInvokerConfig load() {
         return new LambdaInvokerConfig();
     }
@@ -127,6 +158,7 @@ void reload() {
         setConfigData();
         setConfigMap();
     }
+
     public Map<String, Object> getMappedConfig() {
         return mappedConfig;
     }
@@ -160,6 +192,18 @@ private void setConfigData() {
         if(object != null ) {
             metricsName = (String)object;
         }
+        object = mappedConfig.get(MAX_CONCURRENCY);
+        if (object != null) {
+            maxConcurrency = Config.loadIntegerValue(MAX_CONCURRENCY, object);
+        }
+        object = mappedConfig.get(MAX_PENDING_CONNECTION_ACQUIRES);
+        if (object != null) {
+            maxPendingConnectionAcquires = Config.loadIntegerValue(MAX_PENDING_CONNECTION_ACQUIRES, object);
+        }
+        object = mappedConfig.get(CONNECTION_ACQUISITION_TIMEOUT);
+        if (object != null) {
+            connectionAcquisitionTimeout = Config.loadIntegerValue(CONNECTION_ACQUISITION_TIMEOUT, object);
+        }
     }
 
     private void setConfigMap() {

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

@@ -7,6 +7,12 @@ 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 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.
+maxPendingConnectionAcquires: ${lambda-invoker.maxPendingConnectionAcquires:10000}
+# The amount of time to wait when acquiring a connection from the pool before timing out in seconds. Default is 10 seconds.
+connectionAcquisitionTimeout: ${lambda-invoker.connectionAcquisitionTimeout:10}
 # The LogType of the execution log of Lambda. Set Tail to include and None to not include.
 logType: ${lambda-invoker.logType:Tail}
 # mapping of the endpoints to Lambda functions. Define a list of functions in values.yml file.