diff --git a/README.md b/README.md
index 2a5bcf9..f4506a9 100644
--- a/README.md
+++ b/README.md
@@ -17,24 +17,24 @@ $cache = new RobiNN\Cache\Cache([
     // Available config options
     'storage'   => 'file', // apcu|file|memcached|redis
     'file'      => [
-        'path' => __DIR__.'/cache',
-        //'secret' => 'secret_key', // Optional, for securing file names
-        //'remove_expired' => true, // Optional, automatically remove all expired keys (it can affect performance)
+        'path' => __DIR__.'/cache', // The path to the folder containing the cached content.
+        //'secret' => 'secret_key', // For securing file names (optional).
+        //'remove_expired' => true, // Automatically remove all expired keys (it can affect performance) (optional).
     ],
     'redis'     => [
-        'host' => '127.0.0.1', // Optional, when a path is specified
-        'port' => 6379, // Optional, when the default port is used
-        //'database' => 0, // Optional
-        //'username' => '', // Optional, requires Redis >= 6.0
-        //'password' => '', // Optional
-        //'path' => '/var/run/redis/redis-server.sock', // Optional
+        'host' => '127.0.0.1', // Optional when a path is specified.
+        'port' => 6379, // Optional when the default port is used.
+        //'database' => 0, // Default database (optional).
+        //'username' => '', // ACL - requires Redis >= 6.0 (optional).
+        //'password' => '', // Optional.
+        //'path' => '/var/run/redis/redis-server.sock', // Unix domain socket (optional).
     ],
     'memcached' => [
-        'host' => '127.0.0.1', // Optional, when a path is specified
-        'port' => 11211, // Optional, when the default port is used
-        //'path' => '/var/run/memcached/memcached.sock', // Optional
-        //'sasl_username' => '', // Optional, when not using SASL
-        //'sasl_password' => '', // Optional, when not using SASL
+        'host' => '127.0.0.1', // Optional when a path is specified.
+        'port' => 11211, // Optional when the default port is used.
+        //'path' => '/var/run/memcached/memcached.sock', // Unix domain socket (optional).
+        //'sasl_username' => '', // SASL auth (optional).
+        //'sasl_password' => '', // SASL auth (optional).
     ],
 ]);
 
@@ -52,14 +52,14 @@ print_r($data); // item-value
 
 ## Methods
 
-| Name        | Type  | Description                 |
-|-------------|-------|-----------------------------|
-| isConnected | bool  | Check connection            |
-| exists      | bool  | Check if the data is cached |
-| set         | void  | Save data to cache          |
-| get         | mixed | Get data by key             |
-| delete      | bool  | Delete data by key          |
-| flush       | void  | Delete all data from cache  |
+| Name        | Return | Description                  |
+|-------------|--------|------------------------------|
+| isConnected | bool   | Check connection.            |
+| exists      | bool   | Check if the data is cached. |
+| set         | bool   | Save data to cache.          |
+| get         | mixed  | Get data by key.             |
+| delete      | bool   | Delete data by key.          |
+| flush       | bool   | Delete all data from cache.  |
 
 ## Requirements
 
diff --git a/src/Cache.php b/src/Cache.php
index 8ab5dbc..ca20367 100644
--- a/src/Cache.php
+++ b/src/Cache.php
@@ -32,9 +32,10 @@ public function __construct(array $config = [], array $custom_storages = []) {
         ], $custom_storages);
 
         $storage = isset($storages[$config['storage']]) ? $config['storage'] : 'file';
-        $server_info = $config[$config['storage']] ?? [];
-        $cache_class = new ($storages[$storage])($server_info);
-        $this->cache = $cache_class instanceof CacheInterface ? $cache_class : new Storages\FileStorage($server_info);
+        $server_info = $config[$storage] ?? [];
+        $this->cache = is_subclass_of($storages[$storage], CacheInterface::class) ?
+            new ($storages[$storage])($server_info) :
+            new Storages\FileStorage($server_info);
     }
 
     /**
@@ -54,8 +55,8 @@ public function exists(string $key): bool {
     /**
      * Save data to cache.
      */
-    public function set(string $key, mixed $data, int $seconds = 0): void {
-        $this->cache->set($key, $data, $seconds);
+    public function set(string $key, mixed $data, int $seconds = 0): bool {
+        return $this->cache->set($key, $data, $seconds);
     }
 
     /**
diff --git a/src/CacheInterface.php b/src/CacheInterface.php
index 77d39fd..5401098 100644
--- a/src/CacheInterface.php
+++ b/src/CacheInterface.php
@@ -17,7 +17,7 @@ public function isConnected(): bool;
 
     public function exists(string $key): bool;
 
-    public function set(string $key, mixed $data, int $seconds = 0): void;
+    public function set(string $key, mixed $data, int $seconds = 0): bool;
 
     public function get(string $key): mixed;
 
diff --git a/src/Storages/APCuStorage.php b/src/Storages/APCuStorage.php
index 8607065..24ff6b2 100644
--- a/src/Storages/APCuStorage.php
+++ b/src/Storages/APCuStorage.php
@@ -33,8 +33,8 @@ public function exists(string $key): bool {
         return apcu_exists($key);
     }
 
-    public function set(string $key, mixed $data, int $seconds = 0): void {
-        apcu_store($key, serialize($data), $seconds);
+    public function set(string $key, mixed $data, int $seconds = 0): bool {
+        return apcu_store($key, serialize($data), $seconds);
     }
 
     public function get(string $key): mixed {
diff --git a/src/Storages/FileStorage.php b/src/Storages/FileStorage.php
index 06ad34f..5b39647 100644
--- a/src/Storages/FileStorage.php
+++ b/src/Storages/FileStorage.php
@@ -52,7 +52,7 @@ public function exists(string $key): bool {
         return is_file($this->getFileName($key)) && !$this->isExpired($key);
     }
 
-    public function set(string $key, mixed $data, int $seconds = 0): void {
+    public function set(string $key, mixed $data, int $seconds = 0): bool {
         $file = $this->getFileName($key);
 
         try {
@@ -64,9 +64,13 @@ public function set(string $key, mixed $data, int $seconds = 0): void {
 
             if (@file_put_contents($file, $json, LOCK_EX) === strlen((string) $json)) {
                 @chmod($file, 0777);
+
+                return true;
             }
-        } catch (JsonException $e) {
-            echo $e->getMessage();
+
+            return false;
+        } catch (JsonException) {
+            return false;
         }
     }
 
diff --git a/src/Storages/MemcachedStorage.php b/src/Storages/MemcachedStorage.php
index 96a2bf3..b1cbe19 100644
--- a/src/Storages/MemcachedStorage.php
+++ b/src/Storages/MemcachedStorage.php
@@ -43,14 +43,9 @@ public function __construct(array $server) {
         }
 
         if (isset($server['path'])) {
-            $memcached_server = $server['path'];
-
             $this->memcached->addServer($server['path'], 0);
         } else {
             $server['port'] ??= 11211;
-
-            $memcached_server = $server['host'].':'.$server['port'];
-
             $this->memcached->addServer($server['host'], (int) $server['port']);
         }
 
@@ -71,7 +66,8 @@ public function __construct(array $server) {
         }
 
         if (!$this->connection) {
-            throw new CacheException(sprintf('Failed to connect to Memcached server (%s).', $memcached_server));
+            $connection = $server['path'] ?? $server['host'].':'.$server['port'];
+            throw new CacheException(sprintf('Failed to connect to Memcached server %s.', $connection));
         }
     }
 
@@ -83,12 +79,12 @@ public function exists(string $key): bool {
         return (bool) $this->memcached->get($key);
     }
 
-    public function set(string $key, mixed $data, int $seconds = 0): void {
+    public function set(string $key, mixed $data, int $seconds = 0): bool {
         if ($this->is_memcached) {
-            $this->memcached->set($key, serialize($data), $seconds);
-        } else {
-            $this->memcached->set($key, serialize($data), 0, $seconds);
+            return $this->memcached->set($key, serialize($data), $seconds);
         }
+
+        return $this->memcached->set($key, serialize($data), 0, $seconds);
     }
 
     public function get(string $key): mixed {
diff --git a/src/Storages/RedisStorage.php b/src/Storages/RedisStorage.php
index 57df98b..3c4b9a7 100644
--- a/src/Storages/RedisStorage.php
+++ b/src/Storages/RedisStorage.php
@@ -34,13 +34,7 @@ public function __construct(array $server) {
             throw new CacheException('Redis extension is not installed.');
         }
 
-        if (isset($server['path'])) {
-            $redis_server = $server['path'];
-        } else {
-            $server['port'] ??= 6379;
-
-            $redis_server = $server['host'].':'.$server['port'];
-        }
+        $server['port'] ??= 6379;
 
         try {
             if (isset($server['path'])) {
@@ -48,14 +42,7 @@ public function __construct(array $server) {
             } else {
                 $this->redis->connect($server['host'], (int) $server['port'], 3);
             }
-        } catch (RedisException $e) {
-            $this->connection = false;
-            throw new CacheException(
-                sprintf('Failed to connect to Redis server (%s). Error: %s', $redis_server, $e->getMessage())
-            );
-        }
 
-        try {
             if (isset($server['password'])) {
                 if (isset($server['username'])) {
                     $credentials = [$server['username'], $server['password']];
@@ -65,20 +52,11 @@ public function __construct(array $server) {
 
                 $this->redis->auth($credentials);
             }
-        } catch (RedisException $e) {
-            throw new CacheException(
-                sprintf('Could not authenticate with Redis server (%s). Error: %s', $redis_server, $e->getMessage())
-            );
-        }
-
-        try {
-            $server['database'] ??= 0;
 
-            $this->redis->select($server['database']);
+            $this->redis->select($server['database'] ?? 0);
         } catch (RedisException $e) {
-            throw new CacheException(
-                sprintf('Could not select Redis database (%s). Error: %s', $redis_server, $e->getMessage())
-            );
+            $connection = $server['path'] ?? $server['host'].':'.$server['port'];
+            throw new CacheException($e->getMessage().' ['.$connection.']');
         }
     }
 
@@ -94,14 +72,15 @@ public function exists(string $key): bool {
         }
     }
 
-    public function set(string $key, mixed $data, int $seconds = 0): void {
+    public function set(string $key, mixed $data, int $seconds = 0): bool {
         try {
             if ($seconds > 0) {
-                $this->redis->setex($key, $seconds, serialize($data));
-            } else {
-                $this->redis->set($key, serialize($data));
+                return $this->redis->setex($key, $seconds, serialize($data));
             }
+
+            return $this->redis->set($key, serialize($data));
         } catch (RedisException) {
+            return false;
         }
     }
 
diff --git a/tests/CacheTest.php b/tests/CacheTest.php
index 3739f95..7a23452 100644
--- a/tests/CacheTest.php
+++ b/tests/CacheTest.php
@@ -26,7 +26,7 @@ public function testSetterGetter(): void {
         $key = 'cache-test-setter-getter';
         $data = 'itemvalue';
 
-        $this->cache->set($key, $data);
+        $this->assertTrue($this->cache->set($key, $data));
 
         $this->assertTrue($this->cache->exists($key));