diff --git a/Cache.php b/Cache.php
index 0f39985..c2ebd5c 100644
--- a/Cache.php
+++ b/Cache.php
@@ -2,7 +2,137 @@
 
 namespace dcb9\redis;
 
+use yii\di\Instance;
+
 class Cache extends \yii\caching\Cache
 {
+    /**
+     * @var Connection|string|array the Redis [[Connection]] object or the application component ID of the Redis [[Connection]].
+     * This can also be an array that is used to create a redis [[Connection]] instance in case you do not want do configure
+     * redis connection as an application component.
+     * After the Cache object is created, if you want to change this property, you should only assign it
+     * with a Redis [[Connection]] object.
+     */
+    public $redis = 'redis';
+
+    /**
+     * Initializes the redis Cache component.
+     * This method will initialize the [[redis]] property to make sure it refers to a valid redis connection.
+     * @throws \yii\base\InvalidConfigException if [[redis]] is invalid.
+     */
+    public function init()
+    {
+        parent::init();
+        $this->redis = Instance::ensure($this->redis, Connection::className());
+        $this->redis->open();
+    }
+
+
+    /**
+     * @inheritdoc
+     */
+    public function exists($key)
+    {
+        $key = $this->buildKey($key);
+
+        return (bool)$this->redis->exists($key);
+    }
+
+    /**
+     * @inheritdoc
+     */
+    protected function getValue($key)
+    {
+        return $this->redis->get($key);
+    }
+
+    /**
+     * @inheritdoc
+     */
+    protected function getValues($keys)
+    {
+        $response = $this->redis->mget($keys);
+        $result = [];
+        $i = 0;
+        foreach ($keys as $key) {
+            $result[$key] = $response[$i++];
+        }
+
+        return $result;
+    }
+
+    /**
+     * @inheritdoc
+     */
+    protected function setValue($key, $value, $expire)
+    {
+        if ($expire == 0) {
+            return (bool)$this->redis->set($key, $value);
+        } else {
+            return (bool)$this->redis->setex($key, $expire, $value);
+        }
+    }
+
+    /**
+     * @inheritdoc
+     */
+    protected function setValues($data, $expire)
+    {
+        $args = [];
+        foreach ($data as $key => $value) {
+            $args[] = $key;
+            $args[] = $value;
+        }
+        $failedKeys = [];
+        if ($expire == 0) {
+            $this->redis->mset($args);
+        } else {
+            $expire = (int)($expire * 1000);
+            $this->redis->multi();
+            $this->redis->mset($args);
+            $index = [];
+            foreach ($data as $key => $value) {
+                $this->redis->expire($key, $expire);
+                $index[] = $key;
+            }
+            $result = $this->redis->exec();
+            array_shift($result);
+            foreach ($result as $i => $r) {
+                if ($r != 1) {
+                    $failedKeys[] = $index[$i];
+                }
+            }
+        }
+
+        return $failedKeys;
+    }
+
+
+    /**
+     * @inheritdoc
+     */
+    protected function addValue($key, $value, $expire)
+    {
+        if ($expire == 0) {
+            return (bool)$this->redis->set($key, $value);
+        }
+
+        return (bool)$this->redis->setex($key, $expire, $value);
+    }
+
+    /**
+     * @inheritdoc
+     */
+    protected function deleteValue($key)
+    {
+        return (bool)$this->redis->del($key);
+    }
 
+    /**
+     * @inheritdoc
+     */
+    protected function flushValues()
+    {
+        return $this->redis->flushdb();
+    }
 }
diff --git a/Connection.php b/Connection.php
index 0637ea9..2d2b243 100644
--- a/Connection.php
+++ b/Connection.php
@@ -2,9 +2,113 @@
 
 namespace dcb9\redis;
 
-use yii\base\Component;
+use Redis;
+use Yii;
+use yii\base\Configurable;
+use RedisException;
 
-class Connection extends Component
+/**
+ * Class Connection
+ * @package dcb9\redis
+ */
+class Connection extends Redis implements Configurable
 {
+    /**
+     * @var string the hostname or ip address to use for connecting to the redis server. Defaults to 'localhost'.
+     * If [[unixSocket]] is specified, hostname and port will be ignored.
+     */
+    public $hostname = 'localhost';
+    /**
+     * @var integer the port to use for connecting to the redis server. Default port is 6379.
+     * If [[unixSocket]] is specified, hostname and port will be ignored.
+     */
+    public $port = 6379;
+    /**
+     * @var string the unix socket path (e.g. `/var/run/redis/redis.sock`) to use for connecting to the redis server.
+     * This can be used instead of [[hostname]] and [[port]] to connect to the server using a unix socket.
+     * If a unix socket path is specified, [[hostname]] and [[port]] will be ignored.
+     */
+    public $unixSocket;
+    /**
+     * @var string the password for establishing DB connection. Defaults to null meaning no AUTH command is send.
+     * See http://redis.io/commands/auth
+     */
+    public $password;
+    /**
+     * @var integer the redis database to use. This is an integer value starting from 0. Defaults to 0.
+     */
+    public $database = 0;
+    /**
+     * @var float value in seconds (optional, default is 0.0 meaning unlimited)
+     */
+    public $connectionTimeout = 0.0;
 
+    /**
+     * Constructor.
+     * The default implementation does two things:
+     *
+     * - Initializes the object with the given configuration `$config`.
+     * - Call [[init()]].
+     *
+     * If this method is overridden in a child class, it is recommended that
+     *
+     * - the last parameter of the constructor is a configuration array, like `$config` here.
+     * - call the parent implementation at the end of the constructor.
+     *
+     * @param array $config name-value pairs that will be used to initialize the object properties
+     */
+    public function __construct($config = [])
+    {
+        if (!empty($config)) {
+            Yii::configure($this, $config);
+        }
+    }
+
+    /**
+     * Returns the fully qualified name of this class.
+     * @return string the fully qualified name of this class.
+     */
+    public static function className()
+    {
+        return get_called_class();
+    }
+
+    /**
+     * Establishes a DB connection.
+     * It does nothing if a DB connection has already been established.
+     * @throws RedisException if connection fails
+     */
+    public function open()
+    {
+        if ($this->unixSocket !== null) {
+            $isConnected = $this->connect($this->unixSocket);
+        } else {
+            $isConnected = $this->connect($this->hostname, $this->port, $this->connectionTimeout);
+        }
+
+        if ($isConnected === false) {
+            throw new RedisException('Connect to redis server error.');
+        }
+
+        if ($this->password !== null) {
+            $this->auth($this->password);
+        }
+
+        if ($this->database !== null) {
+            $this->select($this->database);
+        }
+    }
+
+    /**
+     * @return bool
+     */
+    public function ping()
+    {
+        return parent::ping() === '+PONG';
+    }
+
+    public function flushdb()
+    {
+        return parent::flushDB();
+    }
 }
diff --git a/Session.php b/Session.php
index c236b3e..5425b61 100644
--- a/Session.php
+++ b/Session.php
@@ -2,7 +2,149 @@
 
 namespace dcb9\redis;
 
+use yii\base\InvalidConfigException;
+use Yii;
+
+/**
+ * Redis Session implements a session component using [redis](http://redis.io/) as the storage medium.
+ *
+ * Redis Session requires redis version 2.6.12 or higher to work properly.
+ *
+ * It needs to be configured with a redis [[Connection]] that is also configured as an application component.
+ * By default it will use the `redis` application component.
+ *
+ * To use redis Session as the session application component, configure the application as follows,
+ *
+ * ~~~
+ * [
+ *     'components' => [
+ *         'session' => [
+ *             'class' => 'dcb9\redis\Session',
+ *             'redis' => [
+ *                 'hostname' => 'localhost',
+ *                 'port' => 6379,
+ *                 'database' => 0,
+ *             ]
+ *         ],
+ *     ],
+ * ]
+ * ~~~
+ *
+ * Or if you have configured the redis [[Connection]] as an application component, the following is sufficient:
+ *
+ * ~~~
+ * [
+ *     'components' => [
+ *         'session' => [
+ *             'class' => 'dcb9\redis\Session',
+ *             // 'redis' => 'redis' // id of the connection application component
+ *         ],
+ *     ],
+ * ]
+ * ~~~
+ *
+ * @property boolean $useCustomStorage Whether to use custom storage. This property is read-only.
+ *
+ * @author Bob chengbin <bob@phpor.me>
+ */
 class Session extends \yii\web\Session
 {
+    /**
+     * @var Connection|string|array the Redis [[Connection]] object or the application component ID of the Redis [[Connection]].
+     * This can also be an array that is used to create a redis [[Connection]] instance in case you do not want do configure
+     * redis connection as an application component.
+     * After the Session object is created, if you want to change this property, you should only assign it
+     * with a Redis [[Connection]] object.
+     */
+    public $redis = 'redis';
+
+    /**
+     * @var string a string prefixed to every cache key so that it is unique. If not set,
+     * it will use a prefix generated from [[Application::id]]. You may set this property to be an empty string
+     * if you don't want to use key prefix. It is recommended that you explicitly set this property to some
+     * static value if the cached data needs to be shared among multiple applications.
+     */
+    public $keyPrefix;
+
+    /**
+     * Initializes the redis Session component.
+     * This method will initialize the [[redis]] property to make sure it refers to a valid redis connection.
+     * @throws InvalidConfigException if [[redis]] is invalid.
+     */
+    public function init()
+    {
+        if (is_string($this->redis)) {
+            $this->redis = Yii::$app->get($this->redis);
+        } elseif (is_array($this->redis)) {
+            if (!isset($this->redis['class'])) {
+                $this->redis['class'] = Connection::className();
+            }
+            $this->redis = Yii::createObject($this->redis);
+        }
+        if (!$this->redis instanceof Connection) {
+            throw new InvalidConfigException("Session::redis must be either a Redis connection instance or the application component ID of a Redis connection.");
+        }
+        if ($this->keyPrefix === null) {
+            $this->keyPrefix = substr(md5(Yii::$app->id), 0, 5);
+        }
+        $this->redis->open();
+
+        parent::init();
+    }
+
+    /**
+     * Returns a value indicating whether to use custom session storage.
+     * This method overrides the parent implementation and always returns true.
+     * @return boolean whether to use custom storage.
+     */
+    public function getUseCustomStorage()
+    {
+        return true;
+    }
+
+    /**
+     * Session read handler.
+     * Do not call this method directly.
+     * @param string $id session ID
+     * @return string the session data
+     */
+    public function readSession($id)
+    {
+        $data = $this->redis->get($this->calculateKey($id));
+
+        return $data === false || $data === null ? '' : $data;
+    }
+
+    /**
+     * Session write handler.
+     * Do not call this method directly.
+     * @param string $id session ID
+     * @param string $data session data
+     * @return boolean whether session write is successful
+     */
+    public function writeSession($id, $data)
+    {
+        return (bool)$this->redis->setex($this->calculateKey($id), $this->getTimeout(), $data);
+    }
+
+    /**
+     * Session destroy handler.
+     * Do not call this method directly.
+     * @param string $id session ID
+     * @return boolean whether session is destroyed successfully
+     */
+    public function destroySession($id)
+    {
+        return (bool)$this->redis->del($this->calculateKey($id));
+    }
 
+    /**
+     * Generates a unique key used for storing session data in cache.
+     * @param string $id session variable name
+     * @return string a safe cache key associated with the session variable name
+     */
+    protected function calculateKey($id)
+    {
+        return $this->keyPrefix . md5(json_encode([__CLASS__, $id]));
+    }
 }
diff --git a/tests/CacheTest.php b/tests/CacheTest.php
index 0253e76..2387274 100644
--- a/tests/CacheTest.php
+++ b/tests/CacheTest.php
@@ -2,7 +2,77 @@
 
 namespace dcb9\redis\tests;
 
+use dcb9\redis\Cache;
+use dcb9\redis\Connection;
+
 class CacheTest extends TestCase
 {
+    private $_cacheInstance = null;
+
+    /**
+     * @return Cache
+     */
+    protected function getCacheInstance()
+    {
+        $params = self::getParam();
+        $connection = new Connection($params);
+        $this->mockApplication(['components' => ['redis' => $connection]]);
+        if ($this->_cacheInstance === null) {
+            $this->_cacheInstance = new Cache();
+        }
+
+        return $this->_cacheInstance;
+    }
+
+    /**
+     * Store a value that is 2 times buffer size big
+     * https://github.com/yiisoft/yii2/issues/743
+     */
+    public function testLargeData()
+    {
+        $cache = $this->getCacheInstance();
+        $data = str_repeat('XX', 8192); // http://www.php.net/manual/en/function.fread.php
+        $key = 'bigdata1';
+        $this->assertFalse($cache->get($key));
+        $cache->set($key, $data);
+        $this->assertTrue($cache->get($key) === $data);
+        // try with multibyte string
+        $data = str_repeat('ЖЫ', 8192); // http://www.php.net/manual/en/function.fread.php
+        $key = 'bigdata2';
+        $this->assertFalse($cache->get($key));
+        $cache->set($key, $data);
+        $this->assertTrue($cache->get($key) === $data);
+    }
+
+    /**
+     * Store a megabyte and see how it goes
+     * https://github.com/yiisoft/yii2/issues/6547
+     */
+    public function testReallyLargeData()
+    {
+        $cache = $this->getCacheInstance();
+        $keys = [];
+        for ($i = 1; $i < 16; $i++) {
+            $key = 'realbigdata' . $i;
+            $data = str_repeat('X', 100 * 1024); // 100 KB
+            $keys[$key] = $data;
+//            $this->assertTrue($cache->get($key) === false); // do not display 100KB in terminal if this fails :)
+            $cache->set($key, $data);
+        }
+        $values = $cache->mget(array_keys($keys));
+        foreach ($keys as $key => $value) {
+            $this->assertArrayHasKey($key, $values);
+            $this->assertTrue($values[$key] === $value);
+        }
+    }
 
+    public function testMultiByteGetAndSet()
+    {
+        $cache = $this->getCacheInstance();
+        $data = ['abc' => 'ежик', 2 => 'def'];
+        $key = 'data1';
+        $this->assertFalse($cache->get($key));
+        $cache->set($key, $data);
+        $this->assertTrue($cache->get($key) === $data);
+    }
 }
diff --git a/tests/ConnectionTest.php b/tests/ConnectionTest.php
index cb68c3b..03411e9 100644
--- a/tests/ConnectionTest.php
+++ b/tests/ConnectionTest.php
@@ -4,4 +4,64 @@
 
 class ConnectionTest extends TestCase
 {
+    /**
+     * test connection to redis and selection of db
+     */
+    public function testConnect()
+    {
+        $db = $this->getConnection(false);
+        $database = $db->database;
+        $db->open();
+        $this->assertTrue($db->ping());
+        $db->set('YIITESTKEY', 'YIITESTVALUE');
+        $db->close();
+
+        $db = $this->getConnection(false);
+        $db->database = $database;
+        $db->open();
+        $this->assertEquals('YIITESTVALUE', $db->get('YIITESTKEY'));
+        $db->close();
+
+        $db = $this->getConnection(false);
+        $db->database = 1;
+        $db->open();
+        $this->assertFalse($db->get('YIITESTKEY'));
+        $db->close();
+    }
+
+    /**
+     * tests whether close cleans up correctly so that a new connect works
+     */
+    public function testReConnect()
+    {
+        $db = $this->getConnection(false);
+        $db->open();
+        $this->assertTrue($db->ping());
+        $db->close();
+        $db->open();
+        $this->assertTrue($db->ping());
+        $db->close();
+    }
+
+    public function keyValueData()
+    {
+        return [
+            [123],
+            [-123],
+            [0],
+            ['test'],
+            ["test\r\ntest"],
+            [''],
+        ];
+    }
+
+    /**
+     * @dataProvider keyValueData
+     */
+    public function testStoreGet($data)
+    {
+        $db = $this->getConnection(true);
+        $db->set('hi', $data);
+        $this->assertEquals($data, $db->get('hi'));
+    }
 }
diff --git a/tests/SessionTest.php b/tests/SessionTest.php
new file mode 100644
index 0000000..237f641
--- /dev/null
+++ b/tests/SessionTest.php
@@ -0,0 +1,33 @@
+<?php
+
+namespace dcb9\redis\tests;
+
+use dcb9\redis\Connection;
+use Yii;
+
+class SessionTest extends TestCase
+{
+    public function testSession()
+    {
+        $params = self::getParam();
+        $params['class'] = Connection::className();
+        $this->mockApplication([
+            'components' => [
+                'redis' => $params,
+                'session' => 'dcb9\\redis\\Session',
+            ]
+        ]);
+
+        $sessionId = 'sessionId';
+        $session = Yii::$app->session;
+        $session->setTimeout(1);
+        $sessionData = json_encode([
+            'sessionId' => $sessionId,
+            'username' => 'bob',
+        ]);
+        $session->writeSession($sessionId, $sessionData);
+        $this->assertEquals($sessionData, $session->readSession($sessionId));
+        $this->assertTrue($session->destroySession($sessionId));
+        $this->assertEquals('', $session->readSession($sessionId));
+    }
+}