diff --git a/CHANGELOG.md b/CHANGELOG.md
index c7672b201..5870d0898 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,9 +4,11 @@ Yii Framework 2 mongodb extension Change Log
 2.1.10 under development
 ------------------------
 
+- Enh #294: Add transactions support (ziaratban)
 - Bug #308: Fix `yii\mongodb\file\Upload::addFile()` error when uploading file with readonly permissions (sparchatus)
 
 
+
 2.1.9 November 19, 2019
 -----------------------
 
diff --git a/src/ActiveRecord.php b/src/ActiveRecord.php
index c720d94b2..8b5a8cdee 100644
--- a/src/ActiveRecord.php
+++ b/src/ActiveRecord.php
@@ -9,6 +9,7 @@
 
 use MongoDB\BSON\Binary;
 use MongoDB\BSON\Type;
+use MongoDB\BSON\ObjectId;
 use Yii;
 use yii\base\InvalidConfigException;
 use yii\db\BaseActiveRecord;
@@ -25,6 +26,27 @@
  */
 abstract class ActiveRecord extends BaseActiveRecord
 {
+    /**
+     * The insert operation. This is mainly used when overriding [[transactions()]] to specify which operations are transactional.
+     */
+    const OP_INSERT = 0x01;
+
+    /**
+     * The update operation. This is mainly used when overriding [[transactions()]] to specify which operations are transactional.
+     */
+    const OP_UPDATE = 0x02;
+
+    /**
+     * The delete operation. This is mainly used when overriding [[transactions()]] to specify which operations are transactional.
+     */
+    const OP_DELETE = 0x04;
+
+    /**
+     * All three operations: insert, update, delete.
+     * This is a shortcut of the expression: OP_INSERT | OP_UPDATE | OP_DELETE.
+     */
+    const OP_ALL = 0x07;
+
     /**
      * Returns the Mongo connection used by this AR class.
      * By default, the "mongodb" application component is used as the Mongo connection.
@@ -208,8 +230,15 @@ public function insert($runValidation = true, $attributes = null)
         if ($runValidation && !$this->validate($attributes)) {
             return false;
         }
-        $result = $this->insertInternal($attributes);
 
+        if (!$this->isTransactional(self::OP_INSERT)) {
+            return $this->insertInternal($attributes);
+        }
+
+        $result = null;
+        static::getDb()->transaction(function() use ($attribute, &$result) {
+            $result = $this->insertInternal($attributes);
+        });
         return $result;
     }
 
@@ -243,6 +272,76 @@ protected function insertInternal($attributes = null)
         return true;
     }
 
+    /**
+     * Saves the changes to this active record into the associated database table.
+     *
+     * This method performs the following steps in order:
+     *
+     * 1. call [[beforeValidate()]] when `$runValidation` is `true`. If [[beforeValidate()]]
+     *    returns `false`, the rest of the steps will be skipped;
+     * 2. call [[afterValidate()]] when `$runValidation` is `true`. If validation
+     *    failed, the rest of the steps will be skipped;
+     * 3. call [[beforeSave()]]. If [[beforeSave()]] returns `false`,
+     *    the rest of the steps will be skipped;
+     * 4. save the record into database. If this fails, it will skip the rest of the steps;
+     * 5. call [[afterSave()]];
+     *
+     * In the above step 1, 2, 3 and 5, events [[EVENT_BEFORE_VALIDATE]],
+     * [[EVENT_AFTER_VALIDATE]], [[EVENT_BEFORE_UPDATE]], and [[EVENT_AFTER_UPDATE]]
+     * will be raised by the corresponding methods.
+     *
+     * Only the [[dirtyAttributes|changed attribute values]] will be saved into database.
+     *
+     * For example, to update a customer record:
+     *
+     * ```php
+     * $customer = Customer::findOne($id);
+     * $customer->name = $name;
+     * $customer->email = $email;
+     * $customer->update();
+     * ```
+     *
+     * Note that it is possible the update does not affect any row in the table.
+     * In this case, this method will return 0. For this reason, you should use the following
+     * code to check if update() is successful or not:
+     *
+     * ```php
+     * if ($customer->update() !== false) {
+     *     // update successful
+     * } else {
+     *     // update failed
+     * }
+     * ```
+     *
+     * @param bool $runValidation whether to perform validation (calling [[validate()]])
+     * before saving the record. Defaults to `true`. If the validation fails, the record
+     * will not be saved to the database and this method will return `false`.
+     * @param array $attributeNames list of attributes that need to be saved. Defaults to `null`,
+     * meaning all attributes that are loaded from DB will be saved.
+     * @return int|false the number of rows affected, or false if validation fails
+     * or [[beforeSave()]] stops the updating process.
+     * @throws StaleObjectException if [[optimisticLock|optimistic locking]] is enabled and the data
+     * being updated is outdated.
+     * @throws \Exception|\Throwable in case update failed.
+     */
+    public function update($runValidation = true, $attributeNames = null)
+    {
+        if ($runValidation && !$this->validate($attributeNames)) {
+            Yii::info('Model not updated due to validation error.', __METHOD__);
+            return false;
+        }
+
+        if (!$this->isTransactional(self::OP_UPDATE)) {
+            return $this->updateInternal($attributeNames);
+        }
+
+        $result = null;
+        static::getDb()->transaction(function() use ($attributeNames, &$result) {
+            $result = $this->updateInternal($attributeNames);
+        });
+        return $result;
+    }
+
     /**
      * @see ActiveRecord::update()
      * @throws StaleObjectException
@@ -308,12 +407,14 @@ protected function updateInternal($attributes = null)
      */
     public function delete()
     {
-        $result = false;
-        if ($this->beforeDelete()) {
-            $result = $this->deleteInternal();
-            $this->afterDelete();
+        if (!$this->isTransactional(self::OP_DELETE)) {
+            return $this->deleteInternal();
         }
 
+        $result = null;
+        static::getDb()->transaction(function() use (&$result) {
+            $result = $this->deleteInternal();
+        });
         return $result;
     }
 
@@ -323,6 +424,9 @@ public function delete()
      */
     protected function deleteInternal()
     {
+        if (!$this->beforeDelete()) {
+            return false;
+        }
         // we do not check the return value of deleteAll() because it's possible
         // the record is already deleted in the database and thus the method will return 0
         $condition = $this->getOldPrimaryKey(true);
@@ -335,6 +439,7 @@ protected function deleteInternal()
             throw new StaleObjectException('The object being deleted is outdated.');
         }
         $this->setOldAttributes(null);
+        $this->afterDelete();
 
         return $result;
     }
@@ -411,4 +516,146 @@ private function dumpBsonObject(Type $object)
         }
         return ArrayHelper::toArray($object);
     }
-}
+
+    /**
+     * Locks a document of the collection in a transaction (like `select for update` feature in MySQL)
+     * @see https://www.mongodb.com/blog/post/how-to-select--for-update-inside-mongodb-transactions
+     * @param mixed $id a document id (primary key > _id)
+     * @param string $lockFieldName The name of the field you want to lock.
+     * @param array $modifyOptions list of the options in format: optionName => optionValue.
+     * @param Connection $db the Mongo connection uses it to execute the query.
+     * @return ActiveRecord|null the locked document.
+     * Returns instance of ActiveRecord. Null will be returned if the query does not have a result.
+    */
+    public static function LockDocument($id, $lockFieldName, $modifyOptions = [], $db = null)
+    {
+        $db = $db ? $db : static::getDb();
+        $db->transactionReady('lock document');
+        $options['new'] = true;
+        return static::find()
+            ->where(['_id' => $id])
+            ->modify(
+                [
+                    '$set' =>[$lockFieldName => new ObjectId]
+                ],
+                $modifyOptions,
+                $db
+            )
+        ;
+    }
+
+    /**
+     * Locking a document in stubborn mode on a transaction (like `select for update` feature in MySQL)
+     * @see https://www.mongodb.com/blog/post/how-to-select--for-update-inside-mongodb-transactions
+     * notice : you can not use stubborn mode if transaction is started in current session (or use your session with `mySession` parameter).
+     * @param mixed $id a document id (primary key > _id)
+     * @param array $options list of options in format:
+     *   [
+     *     'mySession' => false,        # A custom session instance of ClientSession for start a transaction.
+     *     'transactionOptions' => [],  # New transaction options. see $transactionOptions in Transaction::start()
+     *     'modifyOptions' => [],       # See $options in ActiveQuery::modify()
+     *     'sleep' => 1000000,          # A time parameter in microseconds to wait. the default is one second.
+     *     'try' => 0,                  # Maximum count of retry. throw write conflict error after reached this value. the zero default is unlimited.
+     *     'lockFieldName' => '_lock'   # The name of the field you want to lock. default is '_lock'
+     *   ]
+     * @param Connection $db the Mongo connection uses it to execute the query.
+     * @return ActiveRecord|null returns the locked document.
+     * Returns instance of ActiveRecord. Null will be returned if the query does not have a result.
+     * When the total number of attempts to lock the document passes `try`, conflict error will be thrown
+    */
+    public static function LockDocumentStubbornly($id, $lockFieldName, $options = [], $db = null)
+    {
+        $db = $db ? $db : static::getDb();
+
+        $options = array_replace_recursive(
+            [
+                'mySession' => false,
+                'transactionOptions' => [],
+                'modifyOptions' => [],
+                'sleep' => 1000000,
+                'try' => 0,
+            ],
+            $options
+        );
+
+        $options['modifyOptions']['new'] = true;
+
+        $session = $options['mySession'] ? $options['mySession'] : $db->startSessionOnce(); 
+
+        if ($session->getInTransaction()) {
+            throw new Exception('You can\'t use stubborn lock feature because current connection is in a transaction.');
+        }
+
+        // start stubborn
+        $tiredCounter = 0;
+        StartStubborn:
+        $session->transaction->start($options['transactionOptions']);
+        try {
+            $doc = static::find()
+                ->where(['_id' => $id])
+                ->modify(
+                    [
+                        '$set' => [
+                            $lockFieldName => new ObjectId
+                        ]
+                    ],
+                    $options['modifyOptions'],
+                    $db
+                );
+            return $doc;
+        } catch(\Exception $e) {
+            $session->transaction->rollBack();
+            $tiredCounter++;
+            if ($options['try'] !== 0 && $tiredCounter === $options['try']) {
+                throw $e;
+            }
+            usleep($options['sleep']);
+            goto StartStubborn;
+        }
+    }
+
+    /**
+     * Declares which DB operations should be performed within a transaction in different scenarios.
+     * The supported DB operations are: [[OP_INSERT]], [[OP_UPDATE]] and [[OP_DELETE]],
+     * which correspond to the [[insert()]], [[update()]] and [[delete()]] methods, respectively.
+     * By default, these methods are NOT enclosed in a DB transaction.
+     *
+     * In some scenarios, to ensure data consistency, you may want to enclose some or all of them
+     * in transactions. You can do so by overriding this method and returning the operations
+     * that need to be transactional. For example,
+     *
+     * ```php
+     * return [
+     *     'admin' => self::OP_INSERT,
+     *     'api' => self::OP_INSERT | self::OP_UPDATE | self::OP_DELETE,
+     *     // the above is equivalent to the following:
+     *     // 'api' => self::OP_ALL,
+     *
+     * ];
+     * ```
+     *
+     * The above declaration specifies that in the "admin" scenario, the insert operation ([[insert()]])
+     * should be done in a transaction; and in the "api" scenario, all the operations should be done
+     * in a transaction.
+     *
+     * @return array the declarations of transactional operations. The array keys are scenarios names,
+     * and the array values are the corresponding transaction operations.
+     */
+    public function transactions()
+    {
+        return [];
+    }
+
+    /**
+     * Returns a value indicating whether the specified operation is transactional in the current [[$scenario]].
+     * @param int $operation the operation to check. Possible values are [[OP_INSERT]], [[OP_UPDATE]] and [[OP_DELETE]].
+     * @return bool whether the specified operation is transactional in the current [[scenario]].
+     */
+    public function isTransactional($operation)
+    {
+        $scenario = $this->getScenario();
+        $transactions = $this->transactions();
+
+        return isset($transactions[$scenario]) && ($transactions[$scenario] & $operation);
+    }
+}
\ No newline at end of file
diff --git a/src/ClientSession.php b/src/ClientSession.php
new file mode 100644
index 000000000..738ec17fc
--- /dev/null
+++ b/src/ClientSession.php
@@ -0,0 +1,173 @@
+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\mongodb;
+
+use Yii;
+use MongoDB\Driver\ReadConcern;
+use MongoDB\Driver\WriteConcern;
+use MongoDB\Driver\ReadPreference;
+
+/**
+ * ClientSession represents a client session and Commands, queries, and write operations may then be associated the session.
+ * @see https://docs.mongodb.com/manual/release-notes/3.6/#client-sessions
+ * Note : The minimum supported version of mongodb php driver is 1.4.0
+ * Note : The minimum supported version of MongoDB server is 3.6
+ * @see https://github.com/mongodb/mongo-php-driver/releases/tag/1.4.0
+ * @see https://docs.mongodb.com/ecosystem/drivers/php/#mongodb-compatibility
+ * @author Abolfazl Ziaratban <abolfazl.ziaratban@gmail.com>
+ */
+class ClientSession extends \yii\base\BaseObject
+{
+
+    /**
+     * @var Connection the database connection that this transaction is associated with.
+     */
+    public $db;
+
+    /**
+     * @var MongoDB\Driver\Session class represents a client session and Commands,
+     * queries, and write operations may then be associated the session.
+     * @see https://www.php.net/manual/en/class.mongodb-driver-session.php
+     */
+    public $mongoSession;
+
+    /**
+     * @var Transaction the current transaction in session. this transaction can only be created once.
+    */
+    private $_transaction = null;
+
+    /**
+    * Prepares options for some purposes
+    * @param array by reference
+    * convert string option to object
+    * [
+    *   'defaultTransactionOptions' => [
+    *       'readConcern' => 'snapshot', 
+    *       'writeConcern' => 'majority',
+    *       'writeConcern' => ['majority',true],
+    *       'readPreference' => 'primary',
+    *   ],
+    * ]
+    * convert to :
+    * [
+    *   'defaultTransactionOptions' => [
+    *       'readConcern' => new \MongoDB\Driver\ReadConcern('snapshot'), 
+    *       'writeConcern' => new \MongoDB\Driver\WriteConcern('majority'),
+    *       'writeConcern' => new \MongoDB\Driver\WriteConcern('majority',true),
+    *       'readPreference' => new \MongoDB\Driver\ReadPreference('primary'), 
+    *   ],
+    * ]
+    */
+    public static function prepareOptions(&$options)
+    {
+        if (array_key_exists('defaultTransactionOptions', $options)) {
+
+            //convert readConcern
+            if (
+                array_key_exists('readConcern', $options['defaultTransactionOptions']) &&
+                is_string($options['defaultTransactionOptions']['readConcern'])
+            ) {
+                $options['defaultTransactionOptions']['readConcern'] = new ReadConcern($options['defaultTransactionOptions']['readConcern']);
+            }
+
+            //convert writeConcern
+            if (array_key_exists('writeConcern',$options['defaultTransactionOptions'])) {
+                if (
+                    is_string($options['defaultTransactionOptions']['writeConcern']) ||
+                    is_int($options['defaultTransactionOptions']['writeConcern'])
+                ) {
+                    $options['defaultTransactionOptions']['writeConcern'] = new WriteConcern($options['defaultTransactionOptions']['writeConcern']);
+                } elseif (is_array($options['defaultTransactionOptions']['writeConcern'])) {
+                    $options['defaultTransactionOptions']['writeConcern'] =
+                        (new \ReflectionClass('\MongoDB\Driver\WriteConcern'))
+                            ->newInstanceArgs(
+                                $options['defaultTransactionOptions']['writeConcern']
+                            )
+                    ;
+                }
+            }
+
+            //Convert readPreference
+            if (array_key_exists('readPreference',$options['defaultTransactionOptions'])) {
+                if (is_string($options['defaultTransactionOptions']['readPreference'])) {
+                    $options['defaultTransactionOptions']['readPreference'] = new ReadPreference($options['defaultTransactionOptions']['readPreference']);
+                } else if(is_array($options['defaultTransactionOptions']['readPreference'])) {
+                    $options['defaultTransactionOptions']['readPreference'] =
+                        (new \ReflectionClass('\MongoDB\Driver\ReadPreference'))
+                            ->newInstanceArgs(
+                                $options['defaultTransactionOptions']['readPreference']
+                            )
+                    ;
+                }
+            }
+        }
+    }
+
+    /**
+     * Returns the logical session ID as string for this session, which may be used to identify this session's operations on the server. 
+     * @see https://www.php.net/manual/en/mongodb-driver-session.getlogicalsessionid.php
+     * @return string
+    */
+    public function getId()
+    {
+        return $this->mongoSession->getLogicalSessionId()->id->jsonSerialize()['$binary'];
+    }
+
+    /**
+     * Starts a new mongodb session in a connection.
+     * @param Connection $db 
+     * @param Array $sessionOptions Creates a ClientSession for the given options {@see https://www.php.net/manual/en/mongodb-driver-manager.startsession.php#refsect1-mongodb-driver-manager.startsession-parameters}
+     * @return ClientSession returns new session base on a session options for the given connection
+    */
+    public static function start($db, $sessionOptions = [])
+    {
+        self::prepareOptions($sessionOptions);
+        if ($db->enableProfiling) {
+            Yii::debug('Starting mongodb session ...', __METHOD__);
+        }
+        $db->trigger(Connection::EVENT_START_SESSION);
+        $newSession = new self([
+            'db' => $db,
+            'mongoSession' => $db->manager->startSession($sessionOptions),
+        ]);
+        if ($db->enableProfiling) {   
+            Yii::debug('MongoDB session started.', __METHOD__);
+        }
+        return $newSession;
+    }
+
+    /**
+     * Gets a current transaction of session or creates a new transaction once
+     * @return Transaction returns current transaction
+    */
+    public function getTransaction()
+    {
+        if ($this->_transaction === null) {
+            return $this->_transaction = new Transaction(['clientSession' => $this]);
+        }
+        return $this->_transaction;
+    }
+
+    /**
+     * Returns true if the transaction is in progress
+     * @return bool
+    */
+    public function getInTransaction()
+    {
+        return $this->mongoSession->isInTransaction();
+    }
+
+    /**
+     * Ends the current session.
+    */
+    public function end()
+    {
+        $this->mongoSession->endSession();
+        $this->db->trigger(Connection::EVENT_END_SESSION);
+    }
+}
\ No newline at end of file
diff --git a/src/Collection.php b/src/Collection.php
index c897fd4cb..281edc718 100644
--- a/src/Collection.php
+++ b/src/Collection.php
@@ -56,23 +56,25 @@ public function getFullName()
 
     /**
      * Drops this collection.
+     * @param array $execOptions {@see Command::dropCollection()}
      * @throws Exception on failure.
      * @return bool whether the operation successful.
      */
-    public function drop()
+    public function drop($execOptions = [])
     {
-        return $this->database->dropCollection($this->name);
+        return $this->database->dropCollection($this->name, $execOptions);
     }
 
     /**
      * Returns the list of defined indexes.
      * @return array list of indexes info.
      * @param array $options list of options in format: optionName => optionValue.
+     * @param array $execOptions {@see Command::listIndexes()}
      * @since 2.1
      */
-    public function listIndexes($options = [])
+    public function listIndexes($options = [], $execOptions = [])
     {
-        return $this->database->createCommand()->listIndexes($this->name, $options);
+        return $this->database->createCommand()->listIndexes($this->name, $options, $execOptions);
     }
 
     /**
@@ -107,23 +109,25 @@ public function listIndexes($options = [])
      *
      * See [[https://docs.mongodb.com/manual/reference/method/db.collection.createIndex/#options-for-all-index-types]]
      * for the full list of options.
+     * @param array $execOptions {@see Command::createIndexes()}
      * @return bool whether operation was successful.
      * @since 2.1
      */
-    public function createIndexes($indexes)
+    public function createIndexes($indexes, $execOptions = [])
     {
-        return $this->database->createCommand()->createIndexes($this->name, $indexes);
+        return $this->database->createCommand()->createIndexes($this->name, $indexes, $execOptions);
     }
 
     /**
      * Drops collection indexes by name.
      * @param string $indexes wildcard for name of the indexes to be dropped.
      * You can use `*` to drop all indexes.
+     * @param array $execOptions {@see Command::dropIndexes()}
      * @return int count of dropped indexes.
      */
-    public function dropIndexes($indexes)
+    public function dropIndexes($indexes, $execOptions = [])
     {
-        $result = $this->database->createCommand()->dropIndexes($this->name, $indexes);
+        $result = $this->database->createCommand()->dropIndexes($this->name, $indexes, $execOptions);
         return $result['nIndexesWas'];
     }
 
@@ -144,13 +148,14 @@ public function dropIndexes($indexes)
      * ```
      *
      * @param array $options list of options in format: optionName => optionValue.
+     * @param array $execOptions {@see Command::createIndexes()}
      * @throws Exception on failure.
      * @return bool whether the operation successful.
      */
-    public function createIndex($columns, $options = [])
+    public function createIndex($columns, $options = [], $execOptions = [])
     {
         $index = array_merge(['key' => $columns], $options);
-        return $this->database->createCommand()->createIndexes($this->name, [$index]);
+        return $this->database->createCommand()->createIndexes($this->name, [$index], $execOptions);
     }
 
     /**
@@ -171,17 +176,18 @@ public function createIndex($columns, $options = [])
      * ]
      * ```
      *
+     * @param array $execOptions {@see Command::dropIndexes()}
      * @throws Exception on failure.
      * @return bool whether the operation successful.
      */
-    public function dropIndex($columns)
+    public function dropIndex($columns, $execOptions = [])
     {
         $existingIndexes = $this->listIndexes();
 
         $indexKey = $this->database->connection->getQueryBuilder()->buildSortFields($columns);
         foreach ($existingIndexes as $index) {
             if ($index['key'] == $indexKey) {
-                $this->database->createCommand()->dropIndexes($this->name, $index['name']);
+                $this->database->createCommand()->dropIndexes($this->name, $index['name'], $execOptions);
                 return true;
             }
         }
@@ -190,7 +196,7 @@ public function dropIndex($columns)
         $indexName = $this->database->connection->getQueryBuilder()->generateIndexName($indexKey);
         foreach ($existingIndexes as $index) {
             if ($index['name'] === $indexName) {
-                $this->database->createCommand()->dropIndexes($this->name, $index['name']);
+                $this->database->createCommand()->dropIndexes($this->name, $index['name'], $execOptions);
                 return true;
             }
         }
@@ -200,12 +206,13 @@ public function dropIndex($columns)
 
     /**
      * Drops all indexes for this collection.
+     * @param array $execOptions {@see Command::dropIndexes()}
      * @throws Exception on failure.
      * @return int count of dropped indexes.
      */
-    public function dropAllIndexes()
+    public function dropAllIndexes($execOptions = [])
     {
-        $result = $this->database->createCommand()->dropIndexes($this->name, '*');
+        $result = $this->database->createCommand()->dropIndexes($this->name, '*', $execOptions);
         return isset($result['nIndexesWas']) ? $result['nIndexesWas'] : 0;
     }
 
@@ -215,15 +222,16 @@ public function dropAllIndexes()
      * @param array $condition query condition
      * @param array $fields fields to be selected
      * @param array $options query options (available since 2.1).
+     * @param array $execOptions {@see Command::find()}
      * @return \MongoDB\Driver\Cursor cursor for the search results
      * @see Query
      */
-    public function find($condition = [], $fields = [], $options = [])
+    public function find($condition = [], $fields = [], $options = [], $execOptions = [])
     {
         if (!empty($fields)) {
             $options['projection'] = $fields;
         }
-        return $this->database->createCommand()->find($this->name, $condition, $options);
+        return $this->database->createCommand()->find($this->name, $condition, $options, $execOptions);
     }
 
     /**
@@ -231,12 +239,13 @@ public function find($condition = [], $fields = [], $options = [])
      * @param array $condition query condition
      * @param array $fields fields to be selected
      * @param array $options query options (available since 2.1).
+     * @param array $execOptions {@see find()}
      * @return array|null the single document. Null is returned if the query results in nothing.
      */
-    public function findOne($condition = [], $fields = [], $options = [])
+    public function findOne($condition = [], $fields = [], $options = [], $execOptions = [])
     {
         $options['limit'] = 1;
-        $cursor = $this->find($condition, $fields, $options);
+        $cursor = $this->find($condition, $fields, $options, $execOptions);
         $rows = $cursor->toArray();
         return empty($rows) ? null : current($rows);
     }
@@ -246,12 +255,13 @@ public function findOne($condition = [], $fields = [], $options = [])
      * @param array $condition query condition
      * @param array $update update criteria
      * @param array $options list of options in format: optionName => optionValue.
+     * @param array $execOptions {@see Command::findAndModify()}
      * @return array|null the original document, or the modified document when $options['new'] is set.
      * @throws Exception on failure.
      */
-    public function findAndModify($condition, $update, $options = [])
+    public function findAndModify($condition, $update, $options = [], $execOptions = [])
     {
-        return $this->database->createCommand()->findAndModify($this->name, $condition, $update, $options);
+        return $this->database->createCommand()->findAndModify($this->name, $condition, $update, $options, $execOptions);
     }
 
     /**
@@ -259,23 +269,25 @@ public function findAndModify($condition, $update, $options = [])
      * @param array|object $data data to be inserted.
      * @param array $options list of options in format: optionName => optionValue.
      * @return \MongoDB\BSON\ObjectID new record ID instance.
+     * @param array $execOptions {@see Command::insert()}
      * @throws Exception on failure.
      */
-    public function insert($data, $options = [])
+    public function insert($data, $options = [], $execOptions = [])
     {
-        return $this->database->createCommand()->insert($this->name, $data, $options);
+        return $this->database->createCommand()->insert($this->name, $data, $options, $execOptions);
     }
 
     /**
      * Inserts several new rows into collection.
      * @param array $rows array of arrays or objects to be inserted.
      * @param array $options list of options in format: optionName => optionValue.
+     * @param array $execOptions {@see Command::batchInsert()}
      * @return array inserted data, each row will have "_id" key assigned to it.
      * @throws Exception on failure.
      */
-    public function batchInsert($rows, $options = [])
+    public function batchInsert($rows, $options = [], $execOptions = [])
     {
-        $insertedIds = $this->database->createCommand()->batchInsert($this->name, $rows, $options);
+        $insertedIds = $this->database->createCommand()->batchInsert($this->name, $rows, $options, $execOptions);
         foreach ($rows as $key => $row) {
             $rows[$key]['_id'] = $insertedIds[$key];
         }
@@ -289,12 +301,13 @@ public function batchInsert($rows, $options = [])
      * @param array $condition description of the objects to update.
      * @param array $newData the object with which to update the matching records.
      * @param array $options list of options in format: optionName => optionValue.
+     * @param array $execOptions {@see Command::update()}
      * @return int|bool number of updated documents or whether operation was successful.
      * @throws Exception on failure.
      */
-    public function update($condition, $newData, $options = [])
+    public function update($condition, $newData, $options = [], $execOptions = [])
     {
-        $writeResult = $this->database->createCommand()->update($this->name, $condition, $newData, $options);
+        $writeResult = $this->database->createCommand()->update($this->name, $condition, $newData, $options, $execOptions);
         return $writeResult->getModifiedCount() + $writeResult->getUpsertedCount();
     }
 
@@ -303,16 +316,17 @@ public function update($condition, $newData, $options = [])
      * @param array|object $data data to be updated/inserted.
      * @param array $options list of options in format: optionName => optionValue.
      * @return \MongoDB\BSON\ObjectID updated/new record id instance.
+     * @param array $execOptions {@see Command::insert()}
      * @throws Exception on failure.
      */
-    public function save($data, $options = [])
+    public function save($data, $options = [], $execOptions = [])
     {
         if (empty($data['_id'])) {
-            return $this->insert($data, $options);
+            return $this->insert($data, $options, $execOptions);
         }
         $id = $data['_id'];
         unset($data['_id']);
-        $this->update(['_id' => $id], ['$set' => $data], ['upsert' => true]);
+        $this->update(['_id' => $id], ['$set' => $data], ['upsert' => true], $execOptions);
 
         return is_object($id) ? $id : new ObjectID($id);
     }
@@ -321,13 +335,14 @@ public function save($data, $options = [])
      * Removes data from the collection.
      * @param array $condition description of records to remove.
      * @param array $options list of options in format: optionName => optionValue.
+     * @param array $execOptions {@see Command::delete()}
      * @return int|bool number of updated documents or whether operation was successful.
      * @throws Exception on failure.
      */
-    public function remove($condition = [], $options = [])
+    public function remove($condition = [], $options = [], $execOptions = [])
     {
         $options = array_merge(['limit' => 0], $options);
-        $writeResult = $this->database->createCommand()->delete($this->name, $condition, $options);
+        $writeResult = $this->database->createCommand()->delete($this->name, $condition, $options, $execOptions);
         return $writeResult->getDeletedCount();
     }
 
@@ -335,12 +350,13 @@ public function remove($condition = [], $options = [])
      * Counts records in this collection.
      * @param array $condition query condition
      * @param array $options list of options in format: optionName => optionValue.
+     * @param array $execOptions {@see Command::count()}
      * @return int records count.
      * @since 2.1
      */
-    public function count($condition = [], $options = [])
+    public function count($condition = [], $options = [], $execOptions = [])
     {
-        return $this->database->createCommand()->count($this->name, $condition, $options);
+        return $this->database->createCommand()->count($this->name, $condition, $options, $execOptions);
     }
 
     /**
@@ -348,12 +364,13 @@ public function count($condition = [], $options = [])
      * @param string $column column to use.
      * @param array $condition query parameters.
      * @param array $options list of options in format: optionName => optionValue.
+     * @param array $execOptions {@see Command::distinct()}
      * @return array|bool array of distinct values, or "false" on failure.
      * @throws Exception on failure.
      */
-    public function distinct($column, $condition = [], $options = [])
+    public function distinct($column, $condition = [], $options = [], $execOptions = [])
     {
-        return $this->database->createCommand()->distinct($this->name, $column, $condition, $options);
+        return $this->database->createCommand()->distinct($this->name, $column, $condition, $options, $execOptions);
     }
 
     /**
@@ -362,12 +379,13 @@ public function distinct($column, $condition = [], $options = [])
      * otherwise - an array of aggregation results.
      * @param array $pipelines list of pipeline operators.
      * @param array $options optional parameters.
+     * @param array $execOptions {@see Command::aggregate()}
      * @return array|\MongoDB\Driver\Cursor the result of the aggregation.
      * @throws Exception on failure.
      */
-    public function aggregate($pipelines, $options = [])
+    public function aggregate($pipelines, $options = [], $execOptions = [])
     {
-        return $this->database->createCommand()->aggregate($this->name, $pipelines, $options);
+        return $this->database->createCommand()->aggregate($this->name, $pipelines, $options, $execOptions);
     }
 
     /**
@@ -382,12 +400,13 @@ public function aggregate($pipelines, $options = [])
      * @param array $options optional parameters to the group command. Valid options include:
      *  - condition - criteria for including a document in the aggregation.
      *  - finalize - function called once per unique key that takes the final output of the reduce function.
+     * @param array $execOptions {@see Command::group()}
      * @return array the result of the aggregation.
      * @throws Exception on failure.
      */
-    public function group($keys, $initial, $reduce, $options = [])
+    public function group($keys, $initial, $reduce, $options = [], $execOptions = [])
     {
-        return $this->database->createCommand()->group($this->name, $keys, $initial, $reduce, $options);
+        return $this->database->createCommand()->group($this->name, $keys, $initial, $reduce, $options, $execOptions);
     }
 
     /**
@@ -426,11 +445,12 @@ public function group($keys, $initial, $reduce, $options = [])
      * - jsMode: bool, specifies whether to convert intermediate data into BSON format between the execution of the map and reduce functions.
      * - verbose: bool, specifies whether to include the timing information in the result information.
      *
+     * @param array $execOptions {@see Command::mapReduce()}
      * @return string|array the map reduce output collection name or output results.
      * @throws Exception on failure.
      */
-    public function mapReduce($map, $reduce, $out, $condition = [], $options = [])
+    public function mapReduce($map, $reduce, $out, $condition = [], $options = [], $execOptions = [])
     {
-        return $this->database->createCommand()->mapReduce($this->name, $map, $reduce, $out, $condition, $options);
+        return $this->database->createCommand()->mapReduce($this->name, $map, $reduce, $out, $condition, $options, $execOptions);
     }
 }
diff --git a/src/Command.php b/src/Command.php
index e56b0b51c..f8c621174 100644
--- a/src/Command.php
+++ b/src/Command.php
@@ -10,10 +10,10 @@
 use MongoDB\BSON\ObjectID;
 use MongoDB\Driver\BulkWrite;
 use MongoDB\Driver\Exception\RuntimeException;
+use MongoDB\Driver\WriteResult;
 use MongoDB\Driver\ReadConcern;
-use MongoDB\Driver\ReadPreference;
 use MongoDB\Driver\WriteConcern;
-use MongoDB\Driver\WriteResult;
+use MongoDB\Driver\ReadPreference;
 use Yii;
 use yii\base\InvalidConfigException;
 use yii\base\BaseObject;
@@ -74,106 +74,102 @@ class Command extends BaseObject
     public $document = [];
 
     /**
-     * @var ReadPreference|int|string|null command read preference.
-     */
-    private $_readPreference;
-    /**
-     * @var WriteConcern|int|string|null write concern to be used by this command.
-     */
-    private $_writeConcern;
-    /**
-     * @var ReadConcern|string read concern to be used by this command
-     */
-    private $_readConcern;
-
+    * @var array default options for `executeCommand` method of MongoDB\Driver\Manager.
+    */
+    public $globalExecOptions = [];
 
     /**
-     * Returns read preference for this command.
-     * @return ReadPreference read preference.
-     */
-    public function getReadPreference()
+    * prepares execOptions for some purposes
+    * @param array|object|null $execOptions {@see prepareManagerOptions()}
+    */
+    private function prepareExecCommandOptions(&$execOptions)
     {
-        if (!is_object($this->_readPreference)) {
-            if ($this->_readPreference === null) {
-                $this->_readPreference = $this->db->manager->getReadPreference();
-            } elseif (is_scalar($this->_readPreference)) {
-                $this->_readPreference = new ReadPreference($this->_readPreference);
-            }
+        if (empty($execOptions)) {
+            $execOptions = array_merge($this->globalExecOptions['command'],$this->globalExecOptions['share']);
         }
-        return $this->_readPreference;
+        self::prepareManagerOptions($execOptions);
     }
 
     /**
-     * Sets read preference for this command.
-     * @param ReadPreference|int|string|null $readPreference read reference, it can be specified as
-     * instance of [[ReadPreference]] or scalar mode value, for example: `ReadPreference::RP_PRIMARY`.
-     * @return $this self reference.
-     */
-    public function setReadPreference($readPreference)
-    {
-        $this->_readPreference = $readPreference;
-        return $this;
-    }
-
-    /**
-     * Returns write concern for this command.
-     * @return WriteConcern|null write concern to be used in this command.
-     */
-    public function getWriteConcern()
+    * prepares execOptions for some purposes
+    * @param array|object|null $execOptions {@see prepareManagerOptions()}
+    */
+    private function prepareExecBulkWriteOptions(&$execOptions)
     {
-        if ($this->_writeConcern !== null) {
-            if (is_scalar($this->_writeConcern)) {
-                $this->_writeConcern = new WriteConcern($this->_writeConcern);
-            }
+        if (empty($execOptions)) {
+            $execOptions = array_merge($this->globalExecOptions['bulkWrite'],$this->globalExecOptions['share']);
         }
-        return $this->_writeConcern;
+        self::prepareManagerOptions($execOptions);
     }
 
     /**
-     * Sets write concern for this command.
-     * @param WriteConcern|int|string|null $writeConcern write concern, it can be an instance of [[WriteConcern]]
-     * or its scalar mode value, for example: `majority`.
-     * @return $this self reference
-     */
-    public function setWriteConcern($writeConcern)
+    * prepares execOptions for some purposes
+    * @param array|object|null $execOptions {@see prepareManagerOptions()}
+    */
+    private function prepareExecQueryOptions(&$execOptions)
     {
-        $this->_writeConcern = $writeConcern;
-        return $this;
-    }
+        if (empty($execOptions)) {
+            $execOptions = array_merge($this->globalExecOptions['query'],$this->globalExecOptions['share']);
+        }
+        self::prepareManagerOptions($execOptions);
+    }
+
+    /**
+    * preapare Concern and Preference options for easy use
+    * @param array|object $options by reference
+    * convert string option to object
+    * ['readConcern' => 'snapshot'] > ['readConcern' => new \MongoDB\Driver\ReadConcern('snapshot')]
+    * ['writeConcern' => 'majority'] > ['writeConcern' => new \MongoDB\Driver\WriteConcern('majority')]
+    * ['writeConcern' => ['majority',true]] > ['writeConcern' => new \MongoDB\Driver\WriteConcern('majority',true)]
+    * ['readPreference' => 'snapshot'] > ['readPreference' => new \MongoDB\Driver\ReadPreference('primary')]
+    * {@see https://www.php.net/manual/en/mongodb-driver-manager.executecommand.php#refsect1-mongodb-driver-manager.executecommand-parameters}
+    * {@see https://www.php.net/manual/en/mongodb-driver-manager.executebulkwrite.php#refsect1-mongodb-driver-manager.executebulkwrite-parameters}
+    * {@see https://www.php.net/manual/en/mongodb-driver-server.executequery.php#refsect1-mongodb-driver-server.executequery-parameters}
+    */
+    public static function prepareManagerOptions(&$options)
+    {
+        //Convert readConcern option
+        if (array_key_exists('readConcern', $options) && is_string($options['readConcern'])) {
+            $options['readConcern'] = new ReadConcern($options['readConcern']);
+        }
 
-    /**
-     * Retuns read concern for this command.
-     * @return ReadConcern|string read concern to be used in this command.
-     */
-    public function getReadConcern()
-    {
-        if ($this->_readConcern !== null) {
-            if (is_scalar($this->_readConcern)) {
-                $this->_readConcern = new ReadConcern($this->_readConcern);
+        //Convert writeConcern option
+        if (array_key_exists('writeConcern', $options)) {
+            if (is_string($options['writeConcern']) || is_int($options['writeConcern'])) {
+                $options['writeConcern'] = new WriteConcern($options['writeConcern']);
+            } elseif (is_array($options['writeConcern'])) {
+                $options['writeConcern'] = (new \ReflectionClass('\MongoDB\Driver\WriteConcern'))->newInstanceArgs($options['writeConcern']);   
             }
         }
-        return $this->_readConcern;
-    }
 
-    /**
-     * Sets read concern for this command.
-     * @param ReadConcern|string $readConcern read concern, it can be an instance of [[ReadConcern]] or
-     * scalar level value, for example: 'local'.
-     * @return $this self reference
-     */
-    public function setReadConcern($readConcern)
-    {
-        $this->_readConcern = $readConcern;
-        return $this;
-    }
+        //Convert readPreference option
+        if (array_key_exists('readPreference', $options)) {
+            if (is_string($options['readPreference'])) {
+                $options['readPreference'] = new ReadPreference($options['readPreference']);
+            } elseif (is_array($options['readPreference'])) {
+                $options['readPreference'] = (new \ReflectionClass('\MongoDB\Driver\ReadPreference'))->newInstanceArgs($options['readPreference']);
+            }
+        }
+ 
+        //Convert session option
+        if (array_key_exists('session', $options) && $options['session'] instanceof ClientSession) {
+            $options['session'] = $options['session']->mongoSession;
+        }
+   }
 
     /**
      * Executes this command.
+     * @param array $execOptions (@see prepareExecCommandOptions())
+     * Note: "readConcern" and "writeConcern" options will not default to corresponding values from the MongoDB
+     * Connection URI nor will the MongoDB server version be taken into account
+     * @see https://www.php.net/manual/en/mongodb-driver-server.executebulkwrite.php#refsect1-mongodb-driver-server.executebulkwrite-parameters
      * @return \MongoDB\Driver\Cursor result cursor.
      * @throws Exception on failure.
      */
-    public function execute()
+    public function execute($execOptions = [])
     {
+        $this->prepareExecCommandOptions($execOptions);
+
         $databaseName = $this->databaseName === null ? $this->db->defaultDatabaseName : $this->databaseName;
 
         $token = $this->log([$databaseName, 'command'], $this->document, __METHOD__);
@@ -183,7 +179,7 @@ public function execute()
 
             $this->db->open();
             $mongoCommand = new \MongoDB\Driver\Command($this->document);
-            $cursor = $this->db->manager->executeCommand($databaseName, $mongoCommand, $this->getReadPreference());
+            $cursor = $this->db->manager->executeCommand($databaseName, $mongoCommand, $execOptions);
             $cursor->setTypeMap($this->db->typeMap);
 
             $this->endProfile($token, __METHOD__);
@@ -199,16 +195,20 @@ public function execute()
      * Execute commands batch (bulk).
      * @param string $collectionName collection name.
      * @param array $options batch options.
+     * @param array $execOptions (@see prepareExecBulkWriteOptions())
      * @return array array of 2 elements:
      *
      * - 'insertedIds' - contains inserted IDs.
      * - 'result' - [[\MongoDB\Driver\WriteResult]] instance.
      *
+     * @see https://www.php.net/manual/en/mongodb-driver-server.executebulkwrite.php#refsect1-mongodb-driver-server.executebulkwrite-parameters
      * @throws Exception on failure.
      * @throws InvalidConfigException on invalid [[document]] format.
      */
-    public function executeBatch($collectionName, $options = [])
+    public function executeBatch($collectionName, $options = [], $execOptions = [])
     {
+        $this->prepareExecBulkWriteOptions($execOptions);
+
         $databaseName = $this->databaseName === null ? $this->db->defaultDatabaseName : $this->databaseName;
 
         $token = $this->log([$databaseName, $collectionName, 'bulkWrite'], $this->document, __METHOD__);
@@ -236,7 +236,7 @@ public function executeBatch($collectionName, $options = [])
             }
 
             $this->db->open();
-            $writeResult = $this->db->manager->executeBulkWrite($databaseName . '.' . $collectionName, $batch, $this->getWriteConcern());
+            $writeResult = $this->db->manager->executeBulkWrite($databaseName . '.' . $collectionName, $batch, $execOptions);
 
             $this->endProfile($token, __METHOD__);
         } catch (RuntimeException $e) {
@@ -254,11 +254,14 @@ public function executeBatch($collectionName, $options = [])
      * Executes this command as a mongo query
      * @param string $collectionName collection name
      * @param array $options query options.
+     * @param array $execOptions (@see prepareExecQueryOptions())
      * @return \MongoDB\Driver\Cursor result cursor.
      * @throws Exception on failure
      */
-    public function query($collectionName, $options = [])
+    public function query($collectionName, $options = [], $execOptions = [])
     {
+        $this->prepareExecQueryOptions($execOptions);
+
         $databaseName = $this->databaseName === null ? $this->db->defaultDatabaseName : $this->databaseName;
 
         $token = $this->log(
@@ -273,17 +276,12 @@ public function query($collectionName, $options = [])
             __METHOD__
         );
 
-        $readConcern = $this->getReadConcern();
-        if ($readConcern !== null) {
-            $options['readConcern'] = $readConcern;
-        }
-
         try {
             $this->beginProfile($token, __METHOD__);
 
             $query = new \MongoDB\Driver\Query($this->document, $options);
             $this->db->open();
-            $cursor = $this->db->manager->executeQuery($databaseName . '.' . $collectionName, $query, $this->getReadPreference());
+            $cursor = $this->db->manager->executeQuery($databaseName . '.' . $collectionName, $query, $execOptions);
             $cursor->setTypeMap($this->db->typeMap);
 
             $this->endProfile($token, __METHOD__);
@@ -297,13 +295,13 @@ public function query($collectionName, $options = [])
 
     /**
      * Drops database associated with this command.
+     * @param array $execOptions {@see execute()}
      * @return bool whether operation was successful.
      */
-    public function dropDatabase()
+    public function dropDatabase($execOptions = [])
     {
         $this->document = $this->db->getQueryBuilder()->dropDatabase();
-
-        $result = current($this->execute()->toArray());
+        $result = current($this->execute($execOptions)->toArray());
         return $result['ok'] > 0;
     }
 
@@ -311,26 +309,26 @@ public function dropDatabase()
      * Creates new collection in database associated with this command.s
      * @param string $collectionName collection name
      * @param array $options collection options in format: "name" => "value"
+     * @param array $execOptions {@see execute()}
      * @return bool whether operation was successful.
      */
-    public function createCollection($collectionName, array $options = [])
+    public function createCollection($collectionName, array $options = [], $execOptions = [])
     {
         $this->document = $this->db->getQueryBuilder()->createCollection($collectionName, $options);
-
-        $result = current($this->execute()->toArray());
+        $result = current($this->execute($execOptions)->toArray());
         return $result['ok'] > 0;
     }
 
     /**
      * Drops specified collection.
      * @param string $collectionName name of the collection to be dropped.
+     * @param array $execOptions {@see execute()}
      * @return bool whether operation was successful.
      */
-    public function dropCollection($collectionName)
+    public function dropCollection($collectionName, $execOptions = [])
     {
         $this->document = $this->db->getQueryBuilder()->dropCollection($collectionName);
-
-        $result = current($this->execute()->toArray());
+        $result = current($this->execute($execOptions)->toArray());
         return $result['ok'] > 0;
     }
 
@@ -348,13 +346,13 @@ public function dropCollection($collectionName)
      *
      * See [[https://docs.mongodb.com/manual/reference/method/db.collection.createIndex/#options-for-all-index-types]]
      * for the full list of options.
+     * @param array $execOptions {@see execute()}
      * @return bool whether operation was successful.
      */
-    public function createIndexes($collectionName, $indexes)
+    public function createIndexes($collectionName, $indexes, $execOptions = [])
     {
         $this->document = $this->db->getQueryBuilder()->createIndexes($this->databaseName, $collectionName, $indexes);
-
-        $result = current($this->execute()->toArray());
+        $result = current($this->execute($execOptions)->toArray());
         return $result['ok'] > 0;
     }
 
@@ -362,28 +360,29 @@ public function createIndexes($collectionName, $indexes)
      * Drops collection indexes by name.
      * @param string $collectionName collection name.
      * @param string $indexes wildcard for name of the indexes to be dropped.
+     * @param array $execOptions {@see execute()}
      * @return array result data.
      */
-    public function dropIndexes($collectionName, $indexes)
+    public function dropIndexes($collectionName, $indexes, $execOptions = [])
     {
         $this->document = $this->db->getQueryBuilder()->dropIndexes($collectionName, $indexes);
-
-        return current($this->execute()->toArray());
+        return current($this->execute($execOptions)->toArray());
     }
 
     /**
      * Returns information about current collection indexes.
      * @param string $collectionName collection name
      * @param array $options list of options in format: optionName => optionValue.
+     * @param array $execOptions {@see execute()}
      * @return array list of indexes info.
      * @throws Exception on failure.
      */
-    public function listIndexes($collectionName, $options = [])
+    public function listIndexes($collectionName, $options = [], $execOptions = [])
     {
         $this->document = $this->db->getQueryBuilder()->listIndexes($collectionName, $options);
 
         try {
-            $cursor = $this->execute();
+            $cursor = $this->execute($execOptions);
         } catch (Exception $e) {
             // The server may return an error if the collection does not exist.
             $notFoundCodes = [
@@ -405,13 +404,13 @@ public function listIndexes($collectionName, $options = [])
      * @param string $collectionName collection name
      * @param array $condition filter condition
      * @param array $options list of options in format: optionName => optionValue.
+     * @param array $execOptions {@see execute()}
      * @return int records count
      */
-    public function count($collectionName, $condition = [], $options = [])
+    public function count($collectionName, $condition = [], $options = [], $execOptions = [])
     {
         $this->document = $this->db->getQueryBuilder()->count($collectionName, $condition, $options);
-
-        $result = current($this->execute()->toArray());
+        $result = current($this->execute($execOptions)->toArray());
         return $result['n'];
     }
 
@@ -486,13 +485,14 @@ public function addDelete($condition, $options = [])
      * @param string $collectionName collection name
      * @param array $document document content
      * @param array $options list of options in format: optionName => optionValue.
+     * @param array $execOptions {@see executeBatch()}
      * @return ObjectID|bool inserted record ID, `false` - on failure.
      */
-    public function insert($collectionName, $document, $options = [])
+    public function insert($collectionName, $document, $options = [], $execOptions = [])
     {
         $this->document = [];
         $this->addInsert($document);
-        $result = $this->executeBatch($collectionName, $options);
+        $result = $this->executeBatch($collectionName, $options, $execOptions);
 
         if ($result['result']->getInsertedCount() < 1) {
             return false;
@@ -506,9 +506,10 @@ public function insert($collectionName, $document, $options = [])
      * @param string $collectionName collection name
      * @param array[] $documents documents list
      * @param array $options list of options in format: optionName => optionValue.
+     * @param array $execOptions {@see executeBatch()}
      * @return array|false list of inserted IDs, `false` on failure.
      */
-    public function batchInsert($collectionName, $documents, $options = [])
+    public function batchInsert($collectionName, $documents, $options = [], $execOptions = [])
     {
         $this->document = [];
         foreach ($documents as $key => $document) {
@@ -518,7 +519,7 @@ public function batchInsert($collectionName, $documents, $options = [])
             ];
         }
 
-        $result = $this->executeBatch($collectionName, $options);
+        $result = $this->executeBatch($collectionName, $options, $execOptions);
 
         if ($result['result']->getInsertedCount() < 1) {
             return false;
@@ -533,9 +534,10 @@ public function batchInsert($collectionName, $documents, $options = [])
      * @param array $condition filter condition
      * @param array $document data to be updated.
      * @param array $options update options.
+     * @param array $execOptions {@see executeBatch()}
      * @return WriteResult write result.
      */
-    public function update($collectionName, $condition, $document, $options = [])
+    public function update($collectionName, $condition, $document, $options = [], $execOptions = [])
     {
         $batchOptions = [];
         foreach (['bypassDocumentValidation'] as $name) {
@@ -547,7 +549,7 @@ public function update($collectionName, $condition, $document, $options = [])
 
         $this->document = [];
         $this->addUpdate($condition, $document, $options);
-        $result = $this->executeBatch($collectionName, $batchOptions);
+        $result = $this->executeBatch($collectionName, $batchOptions, $execOptions);
 
         return $result['result'];
     }
@@ -557,9 +559,10 @@ public function update($collectionName, $condition, $document, $options = [])
      * @param string $collectionName collection name.
      * @param array $condition filter condition.
      * @param array $options delete options.
+     * @param array $execOptions {@see executeBatch()}
      * @return WriteResult write result.
      */
-    public function delete($collectionName, $condition, $options = [])
+    public function delete($collectionName, $condition, $options = [], $execOptions = [])
     {
         $batchOptions = [];
         foreach (['bypassDocumentValidation'] as $name) {
@@ -571,7 +574,7 @@ public function delete($collectionName, $condition, $options = [])
 
         $this->document = [];
         $this->addDelete($condition, $options);
-        $result = $this->executeBatch($collectionName, $batchOptions);
+        $result = $this->executeBatch($collectionName, $batchOptions, $execOptions);
 
         return $result['result'];
     }
@@ -581,9 +584,10 @@ public function delete($collectionName, $condition, $options = [])
      * @param string $collectionName collection name
      * @param array $condition filter condition
      * @param array $options query options.
+     * @param array $execOptions {@see query()}
      * @return \MongoDB\Driver\Cursor result cursor.
      */
-    public function find($collectionName, $condition, $options = [])
+    public function find($collectionName, $condition, $options = [], $execOptions = [])
     {
         $queryBuilder = $this->db->getQueryBuilder();
 
@@ -612,7 +616,7 @@ public function find($collectionName, $condition, $options = [])
             }
         }
 
-        return $this->query($collectionName, $options);
+        return $this->query($collectionName, $options, $execOptions);
     }
 
     /**
@@ -621,12 +625,13 @@ public function find($collectionName, $condition, $options = [])
      * @param array $condition query condition
      * @param array $update update criteria
      * @param array $options list of options in format: optionName => optionValue.
+     * @param array $execOptions {@see execute()}
      * @return array|null the original document, or the modified document when $options['new'] is set.
      */
-    public function findAndModify($collectionName, $condition = [], $update = [], $options = [])
+    public function findAndModify($collectionName, $condition = [], $update = [], $options = [], $execOptions = [])
     {
         $this->document = $this->db->getQueryBuilder()->findAndModify($collectionName, $condition, $update, $options);
-        $cursor = $this->execute();
+        $cursor = $this->execute($execOptions);
 
         $result = current($cursor->toArray());
 
@@ -643,12 +648,13 @@ public function findAndModify($collectionName, $condition = [], $update = [], $o
      * @param string $fieldName field name to use.
      * @param array $condition query parameters.
      * @param array $options list of options in format: optionName => optionValue.
+     * @param array $execOptions {@see execute()}
      * @return array array of distinct values, or "false" on failure.
      */
-    public function distinct($collectionName, $fieldName, $condition = [], $options = [])
+    public function distinct($collectionName, $fieldName, $condition = [], $options = [], $execOptions = [])
     {
         $this->document = $this->db->getQueryBuilder()->distinct($collectionName, $fieldName, $condition, $options);
-        $cursor = $this->execute();
+        $cursor = $this->execute($execOptions);
 
         $result = current($cursor->toArray());
 
@@ -672,12 +678,13 @@ public function distinct($collectionName, $fieldName, $condition = [], $options
      * @param array $options optional parameters to the group command. Valid options include:
      *  - condition - criteria for including a document in the aggregation.
      *  - finalize - function called once per unique key that takes the final output of the reduce function.
+     * @param array $execOptions {@see execute()}
      * @return array the result of the aggregation.
      */
-    public function group($collectionName, $keys, $initial, $reduce, $options = [])
+    public function group($collectionName, $keys, $initial, $reduce, $options = [], $execOptions = [])
     {
         $this->document = $this->db->getQueryBuilder()->group($collectionName, $keys, $initial, $reduce, $options);
-        $cursor = $this->execute();
+        $cursor = $this->execute($execOptions);
 
         $result = current($cursor->toArray());
 
@@ -705,12 +712,13 @@ public function group($collectionName, $keys, $initial, $reduce, $options = [])
      *  - jsMode: bool, specifies whether to convert intermediate data into BSON format between the execution of the map and reduce functions.
      *  - verbose: bool, specifies whether to include the timing information in the result information.
      *
+     * @param array $execOptions {@see execute()}
      * @return string|array the map reduce output collection name or output results.
      */
-    public function mapReduce($collectionName, $map, $reduce, $out, $condition = [], $options = [])
+    public function mapReduce($collectionName, $map, $reduce, $out, $condition = [], $options = [], $execOptions = [])
     {
         $this->document = $this->db->getQueryBuilder()->mapReduce($collectionName, $map, $reduce, $out, $condition, $options);
-        $cursor = $this->execute();
+        $cursor = $this->execute($execOptions);
 
         $result = current($cursor->toArray());
 
@@ -724,9 +732,10 @@ public function mapReduce($collectionName, $map, $reduce, $out, $condition = [],
      * @param string $collectionName collection name
      * @param array $pipelines list of pipeline operators.
      * @param array $options optional parameters.
+     * @param array $execOptions {@see execute()}
      * @return array|\MongoDB\Driver\Cursor aggregation result.
      */
-    public function aggregate($collectionName, $pipelines, $options = [])
+    public function aggregate($collectionName, $pipelines, $options = [], $execOptions = [])
     {
         if (empty($options['cursor'])) {
             $returnCursor = false;
@@ -736,7 +745,7 @@ public function aggregate($collectionName, $pipelines, $options = [])
         }
 
         $this->document = $this->db->getQueryBuilder()->aggregate($collectionName, $pipelines, $options);
-        $cursor = $this->execute();
+        $cursor = $this->execute($execOptions);
 
         if ($returnCursor) {
             return $cursor;
@@ -749,12 +758,13 @@ public function aggregate($collectionName, $pipelines, $options = [])
      * Return an explanation of the query, often useful for optimization and debugging.
      * @param string $collectionName collection name
      * @param array $query query document.
+     * @param array $execOptions {@see execute()}
      * @return array explanation of the query.
      */
-    public function explain($collectionName, $query)
+    public function explain($collectionName, $query, $execOptions = [])
     {
         $this->document = $this->db->getQueryBuilder()->explain($collectionName, $query);
-        $cursor = $this->execute();
+        $cursor = $this->execute($execOptions);
 
         return current($cursor->toArray());
     }
@@ -763,16 +773,17 @@ public function explain($collectionName, $query)
      * Returns the list of available databases.
      * @param array $condition filter condition.
      * @param array $options options list.
+     * @param array $execOptions {@see execute()}
      * @return array database information
      */
-    public function listDatabases($condition = [], $options = [])
+    public function listDatabases($condition = [], $options = [], $execOptions = [])
     {
         if ($this->databaseName === null) {
             $this->databaseName = 'admin';
         }
         $this->document = $this->db->getQueryBuilder()->listDatabases($condition, $options);
 
-        $cursor = $this->execute();
+        $cursor = $this->execute($execOptions);
         $result = current($cursor->toArray());
 
         if (empty($result['databases'])) {
@@ -785,12 +796,13 @@ public function listDatabases($condition = [], $options = [])
      * Returns the list of available collections.
      * @param array $condition filter condition.
      * @param array $options options list.
+     * @param array $execOptions {@see execute()}
      * @return array collections information.
      */
-    public function listCollections($condition = [], $options = [])
+    public function listCollections($condition = [], $options = [], $execOptions = [])
     {
         $this->document = $this->db->getQueryBuilder()->listCollections($condition, $options);
-        $cursor = $this->execute();
+        $cursor = $this->execute($execOptions);
 
         return $cursor->toArray();
     }
@@ -839,4 +851,4 @@ protected function endProfile($token, $category)
             Yii::endProfile($token, $category);
         }
     }
-}
+}
\ No newline at end of file
diff --git a/src/Connection.php b/src/Connection.php
index 590f29d82..c6e5cb657 100644
--- a/src/Connection.php
+++ b/src/Connection.php
@@ -83,6 +83,26 @@ class Connection extends Component
      * @event Event an event that is triggered after a DB connection is established
      */
     const EVENT_AFTER_OPEN = 'afterOpen';
+    /**
+     * @event yii\base\Event an event that is triggered right before a mongo client session is started
+     */
+    const EVENT_START_SESSION = 'startSession';
+    /**
+     * @event yii\base\Event an event that is triggered right after a mongo client session is ended
+     */
+    const EVENT_END_SESSION = 'endSession';
+    /**
+     * @event yii\base\Event an event that is triggered right before a transaction is started
+     */
+    const EVENT_START_TRANSACTION = 'startTransaction';
+    /**
+     * @event yii\base\Event an event that is triggered right after a transaction is committed
+     */
+    const EVENT_COMMIT_TRANSACTION = 'commitTransaction';
+    /**
+     * @event yii\base\Event an event that is triggered right after a transaction is rolled back
+     */
+    const EVENT_ROLLBACK_TRANSACTION = 'rollbackTransaction';
 
     /**
      * @var string host:port
@@ -155,6 +175,21 @@ class Connection extends Component
      */
     public $fileStreamWrapperClass = 'yii\mongodb\file\StreamWrapper';
 
+    /**
+    * @var array default options for `executeCommand` , executeBulkWrite and executeQuery method of MongoDB\Driver\Manager in `Command` class.
+    */
+    public $globalExecOptions = [
+        /**
+         * Shared between some(or all) methods(executeCommand|executeBulkWrite|executeQuery).
+         * This options are :
+         * - session
+        */
+        'share' => [],
+        'command' => [],
+        'bulkWrite' => [],
+        'query' => [],
+    ];
+
     /**
      * @var string name of the MongoDB database to use by default.
      * If this field left blank, connection instance will attempt to determine it from
@@ -349,7 +384,7 @@ public function open()
             }
             $token = 'Opening MongoDB connection: ' . $this->dsn;
             try {
-                Yii::trace($token, __METHOD__);
+                Yii::debug($token, __METHOD__);
                 Yii::beginProfile($token, __METHOD__);
                 $options = $this->options;
 
@@ -380,7 +415,7 @@ public function open()
     public function close()
     {
         if ($this->manager !== null) {
-            Yii::trace('Closing MongoDB connection: ' . $this->dsn, __METHOD__);
+            Yii::debug('Closing MongoDB connection: ' . $this->dsn, __METHOD__);
             $this->manager = null;
             foreach ($this->_databases as $database) {
                 $database->clearCollections();
@@ -412,6 +447,7 @@ public function createCommand($document = [], $databaseName = null)
             'db' => $this,
             'databaseName' => $databaseName,
             'document' => $document,
+            'globalExecOptions' => $this->globalExecOptions
         ]);
     }
 
@@ -432,4 +468,229 @@ public function registerFileStreamWrapper($force = false)
 
         return $this->fileStreamProtocol;
     }
-}
+
+    /**
+     * Recursive replacement on $this->globalExecOptions with new options. {@see $this->globalExecOptions}
+     * @param array $newExecOptions {@see $this->globalExecOptions}
+     * @return $this
+     */
+    public function execOptions($newExecOptions)
+    {
+        if (empty($newExecOptions)) {
+            $this->globalExecOptions = [];
+        }
+        else {
+            $this->globalExecOptions = array_replace_recursive($this->globalExecOptions, $newExecOptions);
+        }
+        return $this;
+    }
+
+    /**
+     * Ends the previous session and starts the new session.
+     * @param array $sessionOptions see doc of ClientSession::start()
+     * return ClientSession
+    */
+    public function startSession($sessionOptions = [])
+    {
+
+        if ($this->getInSession()) {
+            $this->getSession()->end();
+        }
+
+        $newSession = $this->newSession($sessionOptions);
+        $this->setSession($newSession);
+        return $newSession;
+    }
+
+    /**
+     * Starts a new session if the session has not started, otherwise returns previous session.
+     * @param array $sessionOptions see doc of ClientSession::start()
+     * return ClientSession
+    */
+    public function startSessionOnce($sessionOptions = [])
+    {
+        if ($this->getInSession()) {   
+            return $this->getSession();
+        }
+        return $this->startSession($sessionOptions);
+    }
+
+    /**
+     * Only starts the new session for current connection but this session does not set for current connection.
+     * @param array $sessionOptions see doc of ClientSession::start()
+     * return ClientSession
+    */
+    public function newSession($sessionOptions = [])
+    {
+        return ClientSession::start($this, $sessionOptions);
+    }
+
+    /**
+     * Checks whether the current connection is in session.
+     * return bool
+    */
+    public function getInSession()
+    {
+        return array_key_exists('session',$this->globalExecOptions['share']);
+    }
+
+    /**
+     * Checks that the current connection is in session and transaction
+     * return bool
+    */
+    public function getInTransaction()
+    {
+        return $this->getInSession() && $this->getSession()->getInTransaction();
+    }
+
+    /**
+     * Throws custom error if transaction is not ready in connection 
+     * @param string $operation a custom message to be shown
+    */
+    public function transactionReady($operation)
+    {
+        if (!$this->getInSession()) {
+            throw new Exception('You can\'t ' . $operation . ' because current connection is\'t in a session.');
+        }
+        if (!$this->getSession()->getInTransaction()) {
+            throw new Exception('You can\'t ' . $operation . ' because transaction not started in current session.');
+        }
+    }
+
+    /**
+     * Returns current session
+     * return ClientSession|null
+    */
+    public function getSession()
+    {
+        return $this->getInSession() ? $this->globalExecOptions['share']['session'] : null;
+    }
+
+    /**
+     * Starts a transaction with three steps :
+     * - starts new session if has not started
+     * - starts the transaction in new session
+     * - sets new session to current connection
+     * @param array $transactionOptions see doc of Transaction::start()
+     * @param array $sessionOptions see doc of ClientSession::start()
+     * return ClientSession
+    */
+    public function startTransaction($transactionOptions = [], $sessionOptions = [])
+    {
+        $session = $this->startSession($sessionOptions,true);
+        $session->getTransaction()->start($transactionOptions);
+        return $session;
+    }
+
+    /**
+     * Starts a transaction in current session if the previous transaction was not started in current session.
+     * @param array $transactionOptions see doc of Transaction::start()
+     * @param array $sessionOptions see doc of ClientSession::start()
+     * return ClientSession
+    */
+    public function startTransactionOnce($transactionOptions = [], $sessionOptions = [])
+    {
+        if ($this->getInTransaction()) {
+            return $this->getSession();
+        }
+        return $this->startTransaction($transactionOptions,$sessionOptions);
+    }
+
+    /**
+    * Commits transaction in current session
+    */
+    public function commitTransaction()
+    {
+        $this->transactionReady('commit transaction');
+        $this->getSession()->transaction->commit();
+    }
+
+    /**
+    * Rollbacks transaction in current session
+    */
+    public function rollBackTransaction()
+    {
+        $this->transactionReady('roll back transaction');
+        $this->getSession()->transaction->rollBack();
+    }
+
+    /**
+     * Changes the current session of connection to execute commands (or drop session)
+     * @param ClientSession|null $clientSession new instance of ClientSession to replace
+     * return $this
+    */
+    public function setSession($clientSession)
+    {
+        #drop session
+        if (empty($clientSession)) {
+            unset($this->globalExecOptions['share']['session']);
+        }
+        else {
+            $this->globalExecOptions['share']['session'] = $clientSession;
+        }
+        return $this;
+    }
+
+    /**
+     * Starts and commits a transaction in easy mode.
+     * @param callable $actions your block of code must be runned after transaction started and before commit
+     * if the $actions returns false then transaction rolls back.
+     * @param array $transactionOptions see doc of Transaction::start()
+     * @param array $sessionOptions see doc of ClientSession::start()
+    */
+    public function transaction(callable $actions, $transactionOptions = [], $sessionOptions = [])
+    {
+        $session = $this->startTransaction($transactionOptions, $sessionOptions);
+        $success = false;
+        try {
+            $result = call_user_func($actions, $session);
+            if ($session->getTransaction()->getIsActive()) {
+                if ($result === false) {
+                    $session->getTransaction()->rollBack();
+                }
+                else {
+                    $session->getTransaction()->commit();
+                }
+            }
+            $success = true;
+        } finally {
+            if (!$success && $session->getTransaction()->getIsActive()) {
+                $session->getTransaction()->rollBack();
+            }
+        }
+    }
+
+    /**
+     * Starts and commits transaction in easy mode if the previous transaction was not executed,
+     * otherwise only runs your actions in previous transaction.
+     * @param callable $actions your block of code must be runned after transaction started and before commit
+     * @param array $transactionOptions see doc of Transaction::start()
+     * @param array $sessionOptions see doc of ClientSession::start()
+    */
+    public function transactionOnce(callable $actions, $transactionOptions = [], $sessionOptions = [])
+    {
+        if ($this->getInTransaction()) {
+            $actions();
+        }
+        else {
+            $this->transaction($actions,$transactionOptions,$sessionOptions);
+        }
+    }
+
+    /**
+     * Runs your mongodb command out of session and transaction.
+     * @param callable $actions your block of code must be runned out of session and transaction
+     * @return mixed returns a result of $actions()
+    */
+    public function noTransaction(callable $actions)
+    {
+        $lastSession = $this->getSession();
+        $this->setSession(null);
+        try {
+            $result = $actions();
+        } finally {
+            $this->setSession($lastSession);
+        }
+        return $result;
+    }
+}
\ No newline at end of file
diff --git a/src/Database.php b/src/Database.php
index 395aac79e..0eba51b5a 100644
--- a/src/Database.php
+++ b/src/Database.php
@@ -115,35 +115,38 @@ public function createCommand($document = [])
      * you need to create collection with the specific options.
      * @param string $name name of the collection
      * @param array $options collection options in format: "name" => "value"
+     * @param array $execOptions -> goto Command::execute()
      * @return bool whether operation was successful.
      * @throws Exception on failure.
      */
-    public function createCollection($name, $options = [])
+    public function createCollection($name, $options = [], $execOptions = [])
     {
-        return $this->createCommand()->createCollection($name, $options);
+        return $this->createCommand()->createCollection($name, $options, $execOptions);
     }
 
     /**
      * Drops specified collection.
      * @param string $name name of the collection
+     * @param array $execOptions -> goto Command::execute()
      * @return bool whether operation was successful.
      * @since 2.1
      */
-    public function dropCollection($name)
+    public function dropCollection($name, $execOptions = [])
     {
-        return $this->createCommand()->dropCollection($name);
+        return $this->createCommand()->dropCollection($name, $execOptions);
     }
 
     /**
      * Returns the list of available collections in this database.
      * @param array $condition filter condition.
      * @param array $options options list.
+     * @param array $execOptions -> goto Command::execute()
      * @return array collections information.
      * @since 2.1.1
      */
-    public function listCollections($condition = [], $options = [])
+    public function listCollections($condition = [], $options = [], $execOptions = [])
     {
-        return $this->createCommand()->listCollections($condition, $options);
+        return $this->createCommand()->listCollections($condition, $options, $execOptions);
     }
 
     /**
diff --git a/src/Transaction.php b/src/Transaction.php
new file mode 100644
index 000000000..5c40faeb8
--- /dev/null
+++ b/src/Transaction.php
@@ -0,0 +1,142 @@
+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\mongodb;
+
+use Yii;
+
+/**
+ * In MongoDB, an operation on a single document is atomic. Because you can use embedded documents and
+ * arrays to capture relationships between data in a single document structure instead of normalizing
+ * across multiple documents and collections, this single-document atomicity obviates the need for multi-document
+ * transactions for many practical use cases.
+ * For situations that require atomicity of reads and writes to multiple documents (in a single or multiple collections), 
+ * MongoDB supports multi-document transactions. With distributed transactions, transactions can be used across multiple operations, 
+ * collections, databases, documents, and shards.
+ * @see https://docs.mongodb.com/core/transactions/
+ * Note : At least 1.5 mongodb php driver version is supported.
+ * Note : At least 4.0 MongoDB version is supported.
+ * @see https://docs.mongodb.com/ecosystem/drivers/php/#mongodb-compatibility
+ * Note : Nested transaction not supported.
+ * @see https://docs.mongodb.com/manual/core/transactions/#transactions-and-sessions
+ * @author Abolfazl Ziaratban <abolfazl.ziaratban@gmail.com>
+ */
+class Transaction extends \yii\base\BaseObject
+{
+
+    const STATE_NONE = 'none';
+    const STATE_STARTING = 'starting';
+    const STATE_ABORTED = 'aborted';
+    const STATE_COMMITTED = 'committed';
+
+    /**
+     * @var MongoDB\Driver\Session class represents a client session and Commands, queries, and write operations may then be associated the session.
+     * @see https://www.php.net/manual/en/class.mongodb-driver-session.php
+     */
+    public $clientSession;
+
+    /**
+     * Set debug message if `enableLogging` property is enable in yii\mongodb\Connection
+     * @var string $message please see $this->yiiDebug()
+     * @var string $category please see $this->yiiDebug()
+     */
+    protected function yiiDebug($message, $category = 'mongodb')
+    {
+        if ($this->clientSession->db->enableLogging) {
+            Yii::debug($message,$category);
+        }
+    }
+
+    /**
+     * Begin profile if `enableProfiling` property is enable in yii\mongodb\Connection
+     * @var string $token please see $this->yiiBeginProfile()
+     * @var string $category please see $this->yiiBeginProfile()
+     */
+    protected function yiiBeginProfile($token, $category = 'mongodb')
+    {
+        if ($this->clientSession->db->enableProfiling) {
+            Yii::beginProfile($token,$category);
+        }
+    }
+
+    /**
+     * End profile if `enableProfiling` property is enable in yii\mongodb\Connection
+     * @var string $token please see $this->yiiEndProfile()
+     * @var string $category please see $this->yiiEndProfile()
+     */
+    protected function yiiEndProfile($token, $category = 'mongodb')
+    {
+        if ($this->clientSession->db->enableProfiling) {
+            Yii::endProfile($token,$category);
+        }
+    }
+
+    /**
+     * Returns the transaction state.
+     */
+    public function getState()
+    {
+        return $this->clientSession->mongoSession->getTransactionState();
+    }
+
+    /**
+     * Returns a value indicating whether this transaction is active.
+     * @return bool whether this transaction is active. Only an active transaction
+     * can [[commit()]] or [[rollBack()]].
+     */
+    public function getIsActive()
+    {
+        return $this->clientSession->db->getIsActive() && $this->clientSession->getInTransaction();
+    }
+
+    /**
+     * Start a transaction if session is not in transaction process.
+     * @see https://www.php.net/manual/en/mongodb-driver-session.starttransaction.php
+     * @param array $transactionOptions Options can be passed as argument to this method.
+     * Each element in this options array overrides the corresponding option from the "sessionOptions" option,
+     * if set when starting the session with ClientSession::start().
+     * @see https://www.php.net/manual/en/mongodb-driver-session.starttransaction.php#refsect1-mongodb-driver-session.starttransaction-parameters
+    */
+    public function start($transactionOptions = [])
+    {
+        Command::prepareManagerOptions($transactionOptions);
+        $this->yiiDebug('Starting mongodb transaction ...', __METHOD__);
+        if ($this->clientSession->getInTransaction()) {
+            throw new Exception('Nested transaction not supported');
+        }
+        $this->clientSession->db->trigger(Connection::EVENT_START_TRANSACTION);
+        $this->yiiBeginProfile('mongodb > start transaction(session id => ' . $this->clientSession->getId() . ')');
+        $this->clientSession->mongoSession->startTransaction($transactionOptions);
+        $this->yiiDebug('MongoDB transaction started.', __METHOD__);
+    }
+
+    /**
+     * Commit a transaction.
+     * @see https://www.php.net/manual/en/mongodb-driver-session.committransaction.php
+     */
+    public function commit()
+    {
+        $this->yiiDebug('Committing mongodb transaction ...', __METHOD__);
+        $this->clientSession->mongoSession->commitTransaction();
+        $this->yiiEndProfile('mongodb > start transaction(session id => ' . $this->clientSession->getId() . ')');
+        $this->yiiDebug('Commit mongodb transaction.', __METHOD__);
+        $this->clientSession->db->trigger(Connection::EVENT_COMMIT_TRANSACTION);
+    }
+
+    /**
+     * Rolls back a transaction.
+     * @see https://www.php.net/manual/en/mongodb-driver-session.aborttransaction.php
+     */
+    public function rollBack()
+    {
+        $this->yiiDebug('Rolling back mongodb transaction ...', __METHOD__);
+        $this->clientSession->mongoSession->abortTransaction();
+        $this->yiiEndProfile('mongodb > start transaction(session id => ' . $this->clientSession->getId() . ')');
+        $this->yiiDebug('Roll back mongodb transaction.', __METHOD__);
+        $this->clientSession->db->trigger(Connection::EVENT_ROLLBACK_TRANSACTION);
+    }
+}
\ No newline at end of file
diff --git a/src/file/Collection.php b/src/file/Collection.php
index 860867c96..1ede82dad 100644
--- a/src/file/Collection.php
+++ b/src/file/Collection.php
@@ -128,31 +128,30 @@ public function getFileCollection($refresh = false)
                 'name' => $this->name
             ]);
         }
-
         return $this->_fileCollection;
     }
 
     /**
      * {@inheritdoc}
      */
-    public function drop()
+    public function drop($execOptions = [])
     {
-        return parent::drop() && $this->database->dropCollection($this->getChunkCollection()->name);
+        return parent::drop($execOptions) && $this->database->dropCollection($this->getChunkCollection()->name,$execOptions);
     }
 
     /**
      * {@inheritdoc}
      * @return Cursor cursor for the search results
      */
-    public function find($condition = [], $fields = [], $options = [])
+    public function find($condition = [], $fields = [], $options = [], $execOptions = [])
     {
-        return new Cursor($this, parent::find($condition, $fields, $options));
+        return new Cursor($this, parent::find($condition, $fields, $options, $execOptions));
     }
 
     /**
      * {@inheritdoc}
      */
-    public function remove($condition = [], $options = [])
+    public function remove($condition = [], $options = [], $execOptions = [])
     {
         $fileCollection = $this->getFileCollection();
         $chunkCollection = $this->getChunkCollection();
@@ -166,7 +165,7 @@ public function remove($condition = [], $options = [])
 
         $batchSize = 200;
         $options['batchSize'] = $batchSize;
-        $cursor = $fileCollection->find($condition, ['_id'], $options);
+        $cursor = $fileCollection->find($condition, ['_id'], $options, $execOptions);
         unset($options['limit']);
         $deleteCount = 0;
         $deleteCallback = function ($ids) use ($fileCollection, $chunkCollection, $options) {
diff --git a/src/rbac/MongoDbManager.php b/src/rbac/MongoDbManager.php
index 78f73113d..97b96f9ac 100644
--- a/src/rbac/MongoDbManager.php
+++ b/src/rbac/MongoDbManager.php
@@ -133,7 +133,7 @@ protected function checkAccessFromCache($user, $itemName, $params, $assignments)
 
         $item = $this->items[$itemName];
 
-        Yii::trace($item instanceof Role ? "Checking role: $itemName" : "Checking permission: $itemName", __METHOD__);
+        Yii::debug($item instanceof Role ? "Checking role: $itemName" : "Checking permission: $itemName", __METHOD__);
 
         if (!$this->executeRule($user, $item, $params)) {
             return false;
@@ -172,7 +172,7 @@ protected function checkAccessRecursive($user, $itemName, $params, $assignments)
             return false;
         }
 
-        Yii::trace($item instanceof Role ? "Checking role: $itemName" : "Checking permission: $itemName", __METHOD__);
+        Yii::debug($item instanceof Role ? "Checking role: $itemName" : "Checking permission: $itemName", __METHOD__);
 
         if (!$this->executeRule($user, $item, $params)) {
             return false;