public function getCluster($name, $db = 0, $replicas = 128, $selectRandomSlave = true, $writeOnly = false)
{
if (!isset($this->_cluster[$name])) {
$this->_cluster[$name] = $this->createCluster($name, $db, $replicas, $selectRandomSlave, $writeOnly);
}
return $this->_cluster[$name];
} private function init()
{
/**
* 如果redis使用集群并且加入sentinel做灾备切换，这里可以实现，使用下面的类， 可以实现自动切换，但效率会受到比较大的影响
*/
$sentinel = new Credis_Sentinel(new Credis_Client($this->_cfg['sentinel_host'], $this->_cfg['sentinel_port']));
$this->_cluster = $sentinel->getCluster($this->_cfg['master_name'], $this->_cfg['password']);
}