Fixed#563.patch

Index: src/phpFastCache/Drivers/Memcache/Driver.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- src/phpFastCache/Drivers/Memcache/Driver.php	(revision cd3bf582ea58c90e9610a92ed85dd32b0f455301)
+++ src/phpFastCache/Drivers/Memcache/Driver.php	(date 1516568443195)
@@ -143,6 +143,7 @@
             $servers = [
               [
                 'host' => '127.0.0.1',
+                'path' => false,
                 'port' => 11211,
                 'sasl_user' => false,
                 'sasl_password' => false,
@@ -152,9 +153,15 @@
 
         foreach ($servers as $server) {
             try {
-                if (!$this->instance->addServer($server[ 'host' ], $server[ 'port' ])) {
+                /**
+                 * If path is provided we consider it as an UNIX Socket
+                 */
+                if(!empty($server[ 'path' ]) && !$this->instance->addServer($server[ 'path' ], 0)){
+                    $this->fallback = true;
+                }else if (!empty($server[ 'host' ]) && !$this->instance->addServer($server[ 'host' ], $server[ 'port' ])) {
                     $this->fallback = true;
                 }
+
                 if (!empty($server[ 'sasl_user' ]) && !empty($server[ 'sasl_password' ])) {
                     $this->instance->setSaslAuthData($server[ 'sasl_user' ], $server[ 'sasl_password' ]);
                 }
Index: src/phpFastCache/Drivers/Memcached/Driver.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- src/phpFastCache/Drivers/Memcached/Driver.php	(revision cd3bf582ea58c90e9610a92ed85dd32b0f455301)
+++ src/phpFastCache/Drivers/Memcached/Driver.php	(date 1516568397313)
@@ -137,6 +137,7 @@
             $servers = [
               [
                 'host' => '127.0.0.1',
+                'path' => false,
                 'port' => 11211,
                 'sasl_user' => false,
                 'sasl_password' => false,
@@ -146,9 +147,15 @@
 
         foreach ($servers as $server) {
             try {
-                if (!$this->instance->addServer($server[ 'host' ], $server[ 'port' ])) {
+                /**
+                 * If path is provided we consider it as an UNIX Socket
+                 */
+                if(!empty($server[ 'path' ]) && !$this->instance->addServer($server[ 'path' ], 0)){
+                    $this->fallback = true;
+                }else if (!empty($server[ 'host' ]) && !$this->instance->addServer($server[ 'host' ], $server[ 'port' ])) {
                     $this->fallback = true;
                 }
+
                 if (!empty($server[ 'sasl_user' ]) && !empty($server[ 'sasl_password' ])) {
                     $this->instance->setSaslAuthData($server[ 'sasl_user' ], $server[ 'sasl_password' ]);
                 }
Index: src/phpFastCache/Drivers/Predis/Driver.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- src/phpFastCache/Drivers/Predis/Driver.php	(revision cd3bf582ea58c90e9610a92ed85dd32b0f455301)
+++ src/phpFastCache/Drivers/Predis/Driver.php	(date 1516568076812)
@@ -133,19 +133,34 @@
      */
     protected function driverConnect()
     {
-        $config = isset($this->config[ 'predis' ]) ? $this->config[ 'predis' ] : [];
+        /** Backward compatibility */
+        $config = isset($this->config[ 'predis' ]) ? $this->config[ 'predis' ] : $this->config;
+        $path = isset($config[ 'path' ]) ? (string) $config[ 'path' ] : false;
 
-        $this->instance = new PredisClient(array_merge([
+        $defaultConfig = [
           'host' => '127.0.0.1',
           'port' => 6379,
           'password' => null,
           'database' => null,
-        ], $config));
+        ];
+        $config = array_merge($defaultConfig, $config);
+
+        /**
+         * If path is provided we consider it as an UNIX Socket
+         */
+        if($path){
+            $this->instance = new PredisClient([
+              'scheme' => 'unix',
+              'path' =>  $path
+            ]);
+        }else{
+            $this->instance = new PredisClient($config);
+        }
 
         try {
             $this->instance->connect();
         } catch (PredisConnectionException $e) {
-            throw new phpFastCacheDriverException('Failed to connect to predis server', 0, $e);
+            throw new phpFastCacheDriverException('Failed to connect to predis server. Check the Predis documentation: https://github.com/nrk/predis/tree/v1.1#how-to-install-and-use-predis', 0, $e);
         }
 
         return true;
Index: src/phpFastCache/Drivers/Redis/Driver.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- src/phpFastCache/Drivers/Redis/Driver.php	(revision cd3bf582ea58c90e9610a92ed85dd32b0f455301)
+++ src/phpFastCache/Drivers/Redis/Driver.php	(date 1516568072685)
@@ -135,23 +135,32 @@
             $this->instance = $this->instance ?: new RedisClient();
 
             $host = isset($this->config[ 'host' ]) ? $this->config[ 'host' ] : '127.0.0.1';
+            $path = isset($this->config[ 'path' ]) ? (string) $this->config[ 'path' ] : false;
             $port = isset($this->config[ 'port' ]) ? (int)$this->config[ 'port' ] : '6379';
             $password = isset($this->config[ 'password' ]) ? $this->config[ 'password' ] : '';
-            $database = isset($this->config[ 'database' ]) ? $this->config[ 'database' ] : '';
+            $database = isset($this->config[ 'database' ]) ? $this->config[ 'database' ] : false;
             $timeout = isset($this->config[ 'timeout' ]) ? $this->config[ 'timeout' ] : '';
 
-            if (!$this->instance->connect($host, (int)$port, (int)$timeout)) {
-                return false;
-            } else {
+            /**
+             * If path is provided we consider it as an UNIX Socket
+             */
+            if($path){
+                $isConnected = $this->instance->connect($path);
+            }else{
+                $isConnected = $this->instance->connect($host, (int)$port, (int)$timeout);
+            }
+
+            if (!$isConnected && $path) {
+                return false;
+            } else if(!$path) {
                 if ($password && !$this->instance->auth($password)) {
                     return false;
                 }
-                if ($database) {
-                    $this->instance->select((int)$database);
-                }
-
-                return true;
-            }
+            }
+            if ($database !== false) {
+                $this->instance->select((int)$database);
+            }
+            return true;
         }
     }
 

Come back discussing onto the issue please :)
I made also a Pull request to fix memcached: PHPSocialNetwork/phpfastcache#566