[dynamodb] Improve endpoint and region config

* Upgrade AWS SDK from version 1.10.48 to 1.11.812.

* Introduce a new configuration parameter, dynamodb.region, which
  represents a valid AWS region code (see
  https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-regions-availability-zones.html#concepts-available-regions
  for example). If specifying the region, it is not necessary to specify
  the dynamodb.endpoint parameter.

* Introduce support for non-standard endpoints. Before this commit,
  setting the endpoint to a non-standard one, like a proxy, but
  ultimately connecting to a region different from 'us-east-1' would
  lead to a credential errors due to bad signature:

  ERROR site.ycsb.db.DynamoDBClient
  -com.amazonaws.AmazonServiceException: Credential should be scoped to
  a valid region, not 'us-east-1'.  (Service: AmazonDynamoDBv2; Status
  Code: 400; Error Code: InvalidSignatureException;

  With this commit, if using a proxy as an endpoint, by setting also the
  region via dynamodb.region, it will work with no error.

* Set TCP Keep-Alive to true. Even it makes sense to be used by YCSB, it
  apparently doesn't improve performance notably given the connection
  reuse that the DynamoDB client is doing.

* Update the example config file with the endpoint and region parameters
  and behavior.

dynamodb/conf/dynamodb.properties

@@ -68,9 +68,15 @@
 #when testing in HASH_AND_RANG mode.
 #dynamodb.hashKeyValue = <some value of your choice>
 
-# Endpoint to connect to.For best latency, it is recommended 
-# to choose the endpoint which is closer to the client. 
-# Default is us-east-1
+# AWS Region code to connect to:
+# https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-regions-availability-zones.html#concepts-available-regions 
+# Set this parameter, unless you are using the default value ('us-east-1).
+#dynamodb.region = us-east-1
+
+# Endpoint to connect to. If not set, the endpoint will be set automatically
+# based on the region and for HTTP connections. When using a non-standard
+# endpoint (such as a proxy), the region parameter is still required to generate
+# the proper message's signature.
 #dynamodb.endpoint = http://dynamodb.us-east-1.amazonaws.com
 
 # Strongly recommended to set to uniform.Refer FAQs in README

dynamodb/pom.xml

@@ -33,7 +33,7 @@ LICENSE file.
     <dependency>
       <groupId>com.amazonaws</groupId>
       <artifactId>aws-java-sdk</artifactId>
-      <version>1.10.48</version>
+      <version>1.11.812</version>
     </dependency>
     <dependency>
       <groupId>log4j</groupId>

dynamodb/src/main/java/site/ycsb/db/DynamoDBClient.java

@@ -19,13 +19,15 @@
 import com.amazonaws.AmazonClientException;
 import com.amazonaws.AmazonServiceException;
 import com.amazonaws.ClientConfiguration;
-import com.amazonaws.auth.AWSCredentials;
+import com.amazonaws.auth.AWSStaticCredentialsProvider;
 import com.amazonaws.auth.PropertiesCredentials;
-import com.amazonaws.services.dynamodbv2.AmazonDynamoDBClient;
+import com.amazonaws.client.builder.AwsClientBuilder;
+import com.amazonaws.services.dynamodbv2.AmazonDynamoDB;
+import com.amazonaws.services.dynamodbv2.AmazonDynamoDBClientBuilder;
 import com.amazonaws.services.dynamodbv2.model.*;
-import site.ycsb.*;
 import org.apache.log4j.Level;
 import org.apache.log4j.Logger;
+import site.ycsb.*;
 
 import java.io.File;
 import java.util.HashMap;
@@ -35,7 +37,7 @@
 import java.util.Vector;
 
 /**
- * DynamoDB v1.10.48 client for YCSB.
+ * DynamoDB client for YCSB.
  */
 
 public class DynamoDBClient extends DB {
@@ -52,7 +54,7 @@ private enum PrimaryKeyType {
     HASH_AND_RANGE
   }
 
-  private AmazonDynamoDBClient dynamoDB;
+  private AmazonDynamoDB dynamoDB;
   private String primaryKeyName;
   private PrimaryKeyType primaryKeyType = PrimaryKeyType.HASH;
 
@@ -63,7 +65,8 @@ private enum PrimaryKeyType {
   private String hashKeyName;
 
   private boolean consistentRead = false;
-  private String endpoint = "http://dynamodb.us-east-1.amazonaws.com";
+  private String region = "us-east-1";
+  private String endpoint = null;
   private int maxConnects = 50;
   private static final Logger LOGGER = Logger.getLogger(DynamoDBClient.class);
   private static final Status CLIENT_ERROR = new Status("CLIENT_ERROR", "An error occurred on the client.");
@@ -83,6 +86,7 @@ public void init() throws DBException {
     String primaryKeyTypeString = getProperties().getProperty("dynamodb.primaryKeyType", null);
     String consistentReads = getProperties().getProperty("dynamodb.consistentReads", null);
     String connectMax = getProperties().getProperty("dynamodb.connectMax", null);
+    String configuredRegion = getProperties().getProperty("dynamodb.region", null);
 
     if (null != connectMax) {
       this.maxConnects = Integer.parseInt(connectMax);
@@ -123,12 +127,25 @@ public void init() throws DBException {
       this.hashKeyValue = getProperties().getProperty("dynamodb.hashKeyValue", DEFAULT_HASH_KEY_VALUE);
     }
 
+    if (null != configuredRegion && configuredRegion.length() > 0) {
+      region = configuredRegion;
+    }
+
     try {
-      AWSCredentials credentials = new PropertiesCredentials(new File(credentialsFile));
-      ClientConfiguration cconfig = new ClientConfiguration();
-      cconfig.setMaxConnections(maxConnects);
-      dynamoDB = new AmazonDynamoDBClient(credentials, cconfig);
-      dynamoDB.setEndpoint(this.endpoint);
+      AmazonDynamoDBClientBuilder dynamoDBBuilder = AmazonDynamoDBClientBuilder.standard();
+      dynamoDBBuilder = null == endpoint ?
+          dynamoDBBuilder.withRegion(this.region) :
+          dynamoDBBuilder.withEndpointConfiguration(
+              new AwsClientBuilder.EndpointConfiguration(this.endpoint, this.region)
+          );
+      dynamoDB = dynamoDBBuilder
+          .withClientConfiguration(
+              new ClientConfiguration()
+                  .withTcpKeepAlive(true)
+                  .withMaxConnections(this.maxConnects)
+          )
+          .withCredentials(new AWSStaticCredentialsProvider(new PropertiesCredentials(new File(credentialsFile))))
+          .build();
       primaryKeyName = primaryKey;
       LOGGER.info("dynamodb connection created with " + this.endpoint);
     } catch (Exception e1) {