diff --git a/ActiveDataProvider.php b/ActiveDataProvider.php
index 281869f0e..0e864c716 100644
--- a/ActiveDataProvider.php
+++ b/ActiveDataProvider.php
@@ -95,7 +95,11 @@ protected function prepareModels()
             $query->addOrderBy($sort->getOrders());
         }
 
-        if (is_array(($results = $query->search($this->db)))) {
+        $options = [];
+        if ($pagination !== false) {
+            $options = ['track_total_hits' => 'true'];
+        }
+        if (is_array(($results = $query->search($this->db, $options)))) {
             $this->setQueryResults($results);
             if ($pagination !== false) {
                 $pagination->totalCount = $this->getTotalCount();
@@ -116,7 +120,15 @@ protected function prepareTotalCount()
         }
 
         $results = $this->getQueryResults();
-        return isset($results['hits']['total']) ? (int)$results['hits']['total'] : 0;
+        $totalValue = 0;
+        if(isset($results['hits']['total'])){
+            if(is_array($results['hits']['total']) && isset($results['hits']['total']['value'])) {
+                $totalValue = (int)$results['hits']['total']['value'];
+            } else {
+                $totalValue = (int)$results['hits']['total'];
+            }
+        }
+        return $totalValue;
     }
 
     /**
diff --git a/ActiveFixture.php b/ActiveFixture.php
index e72c26862..e633a82ff 100644
--- a/ActiveFixture.php
+++ b/ActiveFixture.php
@@ -90,7 +90,7 @@ public function load()
         $this->resetIndex();
         $this->data = [];
 
-        $mapping = $this->db->createCommand()->getMapping($this->index, $this->type);
+        $mapping = $this->db->createCommand()->getMapping($this->index);
         if (isset($mapping[$this->index]['mappings'][$this->type]['_id']['path'])) {
             $idField = $mapping[$this->index]['mappings'][$this->type]['_id']['path'];
         } else {
diff --git a/ActiveRecord.php b/ActiveRecord.php
index 121714c35..06759662e 100644
--- a/ActiveRecord.php
+++ b/ActiveRecord.php
@@ -593,6 +593,72 @@ protected function updateInternal($attributes = null, $options = [])
         }
     }
 
+    public function replace($runValidation = true, $attributeNames = null, $options = [])
+    {
+        if ($runValidation && !$this->validate($attributeNames)) {
+            return false;
+        }
+        return $this->replaceInternal($attributeNames, $options);
+    }
+
+    /**
+     * Rewrite full document on save
+     * @param array $attributes attributes to update
+     * @param array $options options given in this parameter are passed to elasticsearch
+     * as request URI parameters. See [[update()]] for details.
+     * @return integer|false the number of rows affected, or false if [[beforeSave()]] stops the updating process.
+     * @throws StaleObjectException if optimistic locking is enabled and the data being updated is outdated.
+     * @throws InvalidParamException if no [[version]] is available and optimistic locking is enabled.
+     * @throws Exception in case update failed.
+     */
+    protected function replaceInternal($attributes = null, $options = [])
+    {
+        if (!$this->beforeSave(false)) {
+            return false;
+        }
+        $values = $this->getAttributes($attributes);
+        if (empty($values)) {
+            $this->afterSave(false, $values);
+            return 0;
+        }
+        if (isset($options['optimistic_locking']) && $options['optimistic_locking']) {
+            if ($this->_version === null) {
+                throw new InvalidParamException('Unable to use optimistic locking on a record that has no version set. Refer to the docs of ActiveRecord::update() for details.');
+            }
+            $options['version'] = $this->_version;
+            unset($options['optimistic_locking']);
+        }
+        try {
+            $result = static::getDb()->createCommand()->insert(
+                static::index(),
+                static::type(),
+                $values,
+                $this->getOldPrimaryKey(false),
+                $options
+            );
+        } catch(Exception $e) {
+            // HTTP 409 is the response in case of failed optimistic locking
+            // http://www.elastic.co/guide/en/elasticsearch/guide/current/optimistic-concurrency-control.html
+            if (isset($e->errorInfo['responseCode']) && $e->errorInfo['responseCode'] == 409) {
+                throw new StaleObjectException('The object being updated is outdated.', $e->errorInfo, $e->getCode(), $e);
+            }
+            throw $e;
+        }
+
+        if (is_array($result) && isset($result['_version'])) {
+            $this->_version = $result['_version'];
+        }
+
+        $changedAttributes = [];
+        foreach ($values as $name => $value) {
+            $changedAttributes[$name] = $this->getOldAttribute($name);
+            $this->setOldAttribute($name, $value);
+        }
+        $this->afterSave(false, $changedAttributes);
+
+        return $result === false ? false : true;
+    }
+
     /**
      * Performs a quick and highly efficient scroll/scan query to get the list of primary keys that
      * satisfy the given condition. If condition is a list of primary keys
diff --git a/Command.php b/Command.php
index 9e2f7ca70..7f5d3f456 100644
--- a/Command.php
+++ b/Command.php
@@ -568,31 +568,26 @@ public function refreshIndex($index)
 
     /**
      * @param string $index
-     * @param string $type
      * @param string|array $mapping
      * @param array $options
      * @return mixed
      * @see http://www.elastic.co/guide/en/elasticsearch/reference/current/indices-put-mapping.html
      */
-    public function setMapping($index, $type, $mapping, $options = [])
+    public function setMapping($index, $mapping, $options = [])
     {
         $body = $mapping !== null ? (is_string($mapping) ? $mapping : Json::encode($mapping)) : null;
 
-        return $this->db->put([$index, '_mapping', $type], $options, $body);
+        return $this->db->put([$index, '_mapping'], $options, $body);
     }
 
     /**
      * @param string $index
-     * @param string $type
      * @return mixed
      * @see http://www.elastic.co/guide/en/elasticsearch/reference/current/indices-get-mapping.html
      */
-    public function getMapping($index = '_all', $type = null)
+    public function getMapping($index = '_all')
     {
         $url = [$index, '_mapping'];
-        if ($type !== null) {
-            $url[] = $type;
-        }
         return $this->db->get($url);
     }
 
@@ -662,4 +657,19 @@ public function getTemplate($name)
     {
         return $this->db->get(['_template', $name]);
     }
+
+    /**
+     * @param $index
+     * @param $mapping
+     * @param array $options
+     * @return mixed
+     * @throws Exception
+     * @throws \yii\base\InvalidConfigException
+     */
+    public function updateMapping($index, $mapping, $options = [])
+    {
+        $body = $mapping !== null ? (is_string($mapping) ? $mapping : Json::encode($mapping)) : null;
+        return $this->db->put([$index, '_mapping'], $options, $body);
+    }
+
 }
diff --git a/DebugAction.php b/DebugAction.php
index 50db9499c..39fbbbc0a 100644
--- a/DebugAction.php
+++ b/DebugAction.php
@@ -56,7 +56,7 @@ public function run($logId, $tag)
         $method = mb_substr($url, 0, $pos = mb_strpos($url, ' '));
         $url = mb_substr($url, $pos + 1);
 
-        $options = ['pretty' => true];
+        $options = ['pretty' => 'true'];
 
         /* @var $db Connection */
         $db = \Yii::$app->get($this->db);
diff --git a/Query.php b/Query.php
index 75f93a63e..8c968635e 100644
--- a/Query.php
+++ b/Query.php
@@ -226,7 +226,7 @@ public function createCommand($db = null)
      */
     public function all($db = null)
     {
-        $result = $this->createCommand($db)->search();
+        $result = $this->createCommand($db)->search(['track_total_hits' => 'true']);
         if ($result === false) {
             throw new Exception('Elasticsearch search query failed.');
         }
@@ -398,7 +398,7 @@ public function count($q = '*', $db = null)
     {
         // performing a query with return size of 0, is equal to getting result stats such as count
         // https://www.elastic.co/guide/en/elasticsearch/reference/5.6/breaking_50_search_changes.html#_literal_search_type_literal
-        $count = $this->createCommand($db)->search(['size' => 0])['hits']['total'];
+        $count = $this->createCommand($db)->search(['size' => 0, 'track_total_hits' => 'true'])['hits']['total']['value'];
         if ($count === false) {
             throw new Exception('Elasticsearch count query failed.');
         }
diff --git a/QueryBuilder.php b/QueryBuilder.php
index c50f87fd1..34e69682c 100644
--- a/QueryBuilder.php
+++ b/QueryBuilder.php
@@ -127,9 +127,6 @@ public function buildOrderBy($columns)
             } else {
                 $column = $name;
             }
-            if ($column == '_id') {
-                $column = '_uid';
-            }
 
             // allow elasticsearch extended syntax as described in http://www.elastic.co/guide/en/elasticsearch/guide/master/_sorting.html
             if (is_array($direction)) {
@@ -216,7 +213,7 @@ private function buildHashCondition($condition)
         foreach ($condition as $attribute => $value) {
             if ($attribute == '_id') {
                 if ($value === null) { // there is no null pk
-                    $parts[] = ['terms' => ['_uid' => []]]; // this condition is equal to WHERE false
+                    $parts[] = ['terms' => ['_id' => []]]; // this condition is equal to WHERE false
                 } else {
                     $parts[] = ['ids' => ['values' => is_array($value) ? $value : [$value]]];
                 }
@@ -317,10 +314,10 @@ private function buildInCondition($operator, $operands)
         $values = (array)$values;
 
         if (empty($values) || $column === []) {
-            return $operator === 'in' ? ['terms' => ['_uid' => []]] : []; // this condition is equal to WHERE false
+            return $operator === 'in' ? ['terms' => ['_id' => []]] : []; // this condition is equal to WHERE false
         }
 
-        if (count($column) > 1) {
+        if (is_array($column) && count($column) > 1) {
             return $this->buildCompositeInCondition($operator, $column, $values);
         } elseif (is_array($column)) {
             $column = reset($column);
@@ -337,7 +334,7 @@ private function buildInCondition($operator, $operands)
         }
         if ($column === '_id') {
             if (empty($values) && $canBeNull) { // there is no null pk
-                $filter = ['terms' => ['_uid' => []]]; // this condition is equal to WHERE false
+                $filter = ['terms' => ['_id' => []]]; // this condition is equal to WHERE false
             } else {
                 $filter = ['ids' => ['values' => array_values($values)]];
                 if ($canBeNull) {
@@ -400,9 +397,6 @@ private function buildHalfBoundedRangeCondition($operator, $operands)
         }
 
         list($column, $value) = $operands;
-        if ($column === '_id') {
-            $column = '_uid';
-        }
 
         $range_operator = null;
 
diff --git a/composer.json b/composer.json
index da2532c0d..449de6840 100644
--- a/composer.json
+++ b/composer.json
@@ -21,9 +21,18 @@
         "yiisoft/yii2": "~2.0.14",
         "ext-curl": "*"
     },
+    "require-dev": {
+        "phpunit/phpunit": "4.8.27|~5.7.21|^6.2"
+    },
     "autoload": {
         "psr-4": { "micetm\\elasticsearch\\": "" }
     },
+    "repositories": [
+       {
+           "type": "composer",
+           "url": "https://asset-packagist.org"
+       }
+    ],
     "extra": {
         "branch-alias": {
             "dev-master": "2.0.x-dev"