How to check if memcache or memcached is installed for PHP?

Question

How do I test if memcache or memcached (for PHP) is installed on my Apache webserver?

Memcache is a caching daemon designed especiall

Answer 1

Use this code to not only check if the memcache extension is enabled, but also whether the daemon is running and able to store and retrieve data successfully:

<?php
if (class_exists('Memcache')) {
    $server = 'localhost';
    if (!empty($_REQUEST['server'])) {
        $server = $_REQUEST['server'];
    }
    $memcache = new Memcache;
    $isMemcacheAvailable = @$memcache->connect($server);

    if ($isMemcacheAvailable) {
        $aData = $memcache->get('data');
        echo '<pre>';
        if ($aData) {
            echo '<h2>Data from Cache:</h2>';
            print_r($aData);
        } else {
            $aData = array(
                'me' => 'you',
                'us' => 'them',
            );
            echo '<h2>Fresh Data:</h2>';
            print_r($aData);
            $memcache->set('data', $aData, 0, 300);
        }
        $aData = $memcache->get('data');
        if ($aData) {
            echo '<h3>Memcache seem to be working fine!</h3>';
        } else {
            echo '<h3>Memcache DOES NOT seem to be working!</h3>';
        }
        echo '</pre>';
    }
}
if (!$isMemcacheAvailable) {
    echo 'Memcache not available';
}

?>

Answer 2

this is my test function that I use to check Memcache on the server

<?php     
public function test()
 {
    // memcache test - make sure you have memcache extension installed and the deamon is up and running
    $memcache = new Memcache;
    $memcache->connect('localhost', 11211) or die ("Could not connect");

    $version = $memcache->getVersion();
    echo "Server's version: ".$version."<br/>\n";

    $tmp_object = new stdClass;
    $tmp_object->str_attr = 'test';
    $tmp_object->int_attr = 123;

    $memcache->set('key', $tmp_object, false, 10) or die ("Failed to save data at the server");
    echo "Store data in the cache (data will expire in 10 seconds)<br/>\n";

    $get_result = $memcache->get('key');
    echo "Data from the cache:<br/>\n";

    var_dump($get_result);
 }

if you see something like this

    Server's version: 1.4.5_4_gaa7839e
    Store data in the cache (data will expire in 10 seconds)
    Data from the cache:
    object(stdClass)#3 (2) { ["str_attr"]=> string(4) "test" ["int_attr"]=> int(123) }

it means that everything is okay

Cheers!

Answer 3

You can look at phpinfo() or check if any of the functions of memcache is available. Ultimately, check whether the Memcache class exists or not.

e.g.

if(class_exists('Memcache')){
  // Memcache is enabled.
}

Answer 4

Note that all of the class_exists, extensions_loaded, and function_exists only check the link between PHP and the memcache package.

To actually check whether memcache is installed you must either:

• know the OS platform and use shell commands to check whether memcache package is installed
• or test whether memcache connection can be established on the expected port

EDIT 2: OK, actually here's an easier complete solution:

if (class_exists('Memcache')) {
    $memcache = new Memcache;
    $isMemcacheAvailable = @$memcache->connect('localhost');
}
if ($isMemcacheAvailable) {
    //...
}

---

Outdated code below

---

EDIT: Actually you must force PHP to throw error on warnings first. Have a look at this SO question answer.

You can then test the connection via:

try {
    $memcache->connect('localhost');
} catch (Exception $e) {
    // well it's not here
}