Scaling example

Often the information can not fit in memory. In this case you can do "sharding" and scale between several Redis servers on several phisical servers.

The tricky part is the hash we use "crc32(md5($key))" which spreads the information between the instances. Note this setup will fail if some of the servers fail. To avoid this you man use replication.

// Servers list...
$servers = array(
	"127.0.0.1:6379",
	"127.0.0.1:6397",
	"127.0.0.1:6739"
);

// Array of Redis()
$r = array();

// Make connection to each server...
foreach($servers as $s){
	list($host, $port") = explode(":", $s);
	
	$rx = new Redis();
	$rx->connect($host, $port);
	$r[] = $rx;
}

// Key to be set / get
$key = "user:435345:first_name";

// Make hash value;
$hash = crc32(md5($key)) % count($servers);

$r[$hash]->set($key, "Peters");

// ...

echo $r[$hash]->get($key);

Redis connection note

The example uses generic connection to the Redis server. To make the example work with our service you will need to use code similar to this one:

// change these parameter according to the information in your instance list
$host = '85.25.11.9';
$port = 1234;
$password = 'somehashcode';
$db = 0;

$r = new Redis();
$r->connect($host, $port);
$r->auth($password);
$r->select($db);

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Note:
Because we want this page to be useful for memcached users, we tagged with memcached all examples that may be "recreated" for memcached server.

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