diff --git a/db/mongodb/src/com/yahoo/ycsb/db/MongoDbClient.java b/db/mongodb/src/com/yahoo/ycsb/db/MongoDbClient.java
index aa978c10..c9afb027 100644
--- a/db/mongodb/src/com/yahoo/ycsb/db/MongoDbClient.java
+++ b/db/mongodb/src/com/yahoo/ycsb/db/MongoDbClient.java
@@ -1,313 +1,319 @@
 /**
  * MongoDB client binding for YCSB.
  *
  * Submitted by Yen Pai on 5/11/2010.
  *
  * https://gist.github.com/000a66b8db2caf42467b#file_mongo_db.java
  *
  */
 
 package com.yahoo.ycsb.db;
 
+import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.Properties;
 import java.util.Set;
 import java.util.Vector;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import org.bson.types.ObjectId;
 
 import com.mongodb.BasicDBObject;
 import com.mongodb.DBAddress;
 import com.mongodb.DBCollection;
 import com.mongodb.DBCursor;
 import com.mongodb.DBObject;
 import com.mongodb.Mongo;
+import com.mongodb.ServerAddress;
 import com.mongodb.WriteConcern;
+
 import com.yahoo.ycsb.DB;
 import com.yahoo.ycsb.DBException;
 
 /**
  * MongoDB client for YCSB framework.
  *
  * Properties to set:
  *
  * mongodb.url=mongodb://localhost:27017
  * mongodb.database=ycsb
  * mongodb.writeConcern=normal
  *
  * @author ypai
  *
  */
 public class MongoDbClient extends DB {
 
     private static final Logger logger = LoggerFactory.getLogger(MongoDbClient.class);
 
     private Mongo mongo;
     private WriteConcern writeConcern;
     private String database;
 
     /**
      * Initialize any state for this DB. Called once per DB instance; there is
      * one DB instance per client thread.
      */
     public void init() throws DBException {
         // initialize MongoDb driver
         Properties props = getProperties();
         String url = props.getProperty("mongodb.url");
         database = props.getProperty("mongodb.database");
         String writeConcernType = props.getProperty("mongodb.writeConcern");
 
         if ("none".equals(writeConcernType)) {
             writeConcern = WriteConcern.NONE;
         } else if ("strict".equals(writeConcernType)) {
             writeConcern = WriteConcern.SAFE;
         } else if ("normal".equals(writeConcernType)) {
             writeConcern = WriteConcern.NORMAL;
         }
 
         try {
             // strip out prefix since Java driver doesn't currently support
-            // standard
-            // connection format URL yet
+            // standard connection format URL yet
             // http://www.mongodb.org/display/DOCS/Connections
             if (url.startsWith("mongodb://")) {
                 url = url.substring(10);
             }
 
-            mongo = new Mongo(new DBAddress(url));
+            ArrayList<ServerAddress> addr = new ArrayList<ServerAddress>();
+            for (String s: url.split(",")) {
+                addr.add(new ServerAddress(s));
+            }
+            mongo = new Mongo(addr);
         } catch (Exception e1) {
             logger.error(
                     "Could not initialize MongoDB connection pool for Loader: "
                             + e1, e1);
             return;
         }
 
     }
 
     @Override
     /**
      * Delete a record from the database.
      *
      * @param table The name of the table
      * @param key The record key of the record to delete.
      * @return Zero on success, a non-zero error code on error. See this class's description for a discussion of error codes.
      */
     public int delete(String table, String key) {
         com.mongodb.DB db=null;
         try {
             db = mongo.getDB(database);
             db.requestStart();
             DBCollection collection = db.getCollection(table);
             DBObject q = new BasicDBObject().append("_id", new ObjectId(key));
             if (writeConcern.equals(WriteConcern.SAFE)) {
                 q.put("$atomic", true);
             }
             collection.remove(q);
 
             // see if record was deleted
             DBObject errors = db.getLastError();
 
             return ((Integer) errors.get("n")) == 1 ? 0 : 1;
         } catch (Exception e) {
             logger.error(e + "", e);
             return 1;
         }
         finally
         {
             if (db!=null)
             {
                 db.requestDone();
             }
         }
     }
 
     @Override
     /**
      * Insert a record in the database. Any field/value pairs in the specified values HashMap will be written into the record with the specified
      * record key.
      *
      * @param table The name of the table
      * @param key The record key of the record to insert.
      * @param values A HashMap of field/value pairs to insert in the record
      * @return Zero on success, a non-zero error code on error. See this class's description for a discussion of error codes.
      */
     public int insert(String table, String key, HashMap<String, String> values) {
         com.mongodb.DB db = null;
         try {
             db = mongo.getDB(database);
 
             db.requestStart();
 
             DBCollection collection = db.getCollection(table);
             DBObject r = new BasicDBObject().append("_id", new ObjectId(key));
             r.putAll(values);
 
             collection.setWriteConcern(writeConcern);
 
             collection.insert(r);
 
             // determine if record was inserted, does not seem to return
             // n=<records affected> for insert
             DBObject errors = db.getLastError();
 
             return (errors.get("ok") != null && errors.get("err") == null) ? 0 : 1;
         } catch (Exception e) {
             logger.error(e + "", e);
             return 1;
         } finally {
             if (db!=null)
             {
                 db.requestDone();
             }
         }
     }
 
     @Override
     @SuppressWarnings("unchecked")
     /**
      * Read a record from the database. Each field/value pair from the result will be stored in a HashMap.
      *
      * @param table The name of the table
      * @param key The record key of the record to read.
      * @param fields The list of fields to read, or null for all of them
      * @param result A HashMap of field/value pairs for the result
      * @return Zero on success, a non-zero error code on error or "not found".
      */
     public int read(String table, String key, Set<String> fields,
             HashMap<String, String> result) {
         com.mongodb.DB db = null;
         try {
             db = mongo.getDB(database);
 
             db.requestStart();
 
             DBCollection collection = db.getCollection(table);
             DBObject q = new BasicDBObject().append("_id", new ObjectId(key));
             DBObject fieldsToReturn = new BasicDBObject();
             boolean returnAllFields = fields == null;
 
             DBObject queryResult = null;
             if (!returnAllFields) {
                 Iterator<String> iter = fields.iterator();
                 while (iter.hasNext()) {
                     fieldsToReturn.put(iter.next(), 1);
                 }
                 queryResult = collection.findOne(q, fieldsToReturn);
             } else {
                 queryResult = collection.findOne(q);
             }
 
             if (queryResult != null) {
                 result.putAll(queryResult.toMap());
             }
             return queryResult != null ? 0 : 1;
         } catch (Exception e) {
             logger.error(e + "", e);
             return 1;
         } finally {
             if (db!=null)
             {
                 db.requestDone();
             }
         }
     }
 
 
     @Override
     /**
      * Update a record in the database. Any field/value pairs in the specified values HashMap will be written into the record with the specified
      * record key, overwriting any existing values with the same field name.
      *
      * @param table The name of the table
      * @param key The record key of the record to write.
      * @param values A HashMap of field/value pairs to update in the record
      * @return Zero on success, a non-zero error code on error. See this class's description for a discussion of error codes.
      */
     public int update(String table, String key, HashMap<String, String> values) {
         com.mongodb.DB db = null;
         try {
             db = mongo.getDB(database);
 
             db.requestStart();
 
             DBCollection collection = db.getCollection(table);
             DBObject q = new BasicDBObject().append("_id", new ObjectId(key));
             DBObject u = new BasicDBObject();
             DBObject fieldsToSet = new BasicDBObject();
             Iterator<String> keys = values.keySet().iterator();
             String tmpKey = null, tmpVal = null;
             while (keys.hasNext()) {
                 tmpKey = keys.next();
                 tmpVal = values.get(tmpKey);
                 fieldsToSet.put(tmpKey, tmpVal);
 
             }
             u.put("$set", fieldsToSet);
 
             collection.setWriteConcern(writeConcern);
 
             collection.update(q, u);
 
             // determine if record was inserted
             DBObject errors = db.getLastError();
 
             return (Integer) errors.get("n") == 1 ? 0 : 1;
         } catch (Exception e) {
             logger.error(e + "", e);
             return 1;
         } finally {
             if (db!=null)
             {
                 db.requestDone();
             }
         }
     }
 
     @Override
     @SuppressWarnings("unchecked")
     /**
      * Perform a range scan for a set of records in the database. Each field/value pair from the result will be stored in a HashMap.
      *
      * @param table The name of the table
      * @param startkey The record key of the first record to read.
      * @param recordcount The number of records to read
      * @param fields The list of fields to read, or null for all of them
      * @param result A Vector of HashMaps, where each HashMap is a set field/value pairs for one record
      * @return Zero on success, a non-zero error code on error. See this class's description for a discussion of error codes.
      */
     public int scan(String table, String startkey, int recordcount,
             Set<String> fields, Vector<HashMap<String, String>> result) {
         com.mongodb.DB db=null;
         try {
             db = mongo.getDB(database);
             db.requestStart();
             DBCollection collection = db.getCollection(table);
             // { "_id":{"$gte":startKey, "$lte":{"appId":key+"\uFFFF"}} }
             DBObject scanRange = new BasicDBObject().append("$gte", startkey);
             DBObject q = new BasicDBObject().append("_id", scanRange);
             DBCursor cursor = collection.find(q).limit(recordcount);
             while (cursor.hasNext()) {
                 //toMap() returns a Map, but result.add() expects a Map<String,String>. Hence, the suppress warnings.
                 result.add((HashMap<String, String>) cursor.next().toMap());
             }
 
             return 0;
         } catch (Exception e) {
             logger.error(e + "", e);
             return 1;
         }
         finally
         {
             if (db!=null)
             {
                 db.requestDone();
             }
         }
 
     }
 }