src/M6Web/Component/Redis/Multi.php
public function onOneKeyServer($key)
    {
        $this->selectedRedis[] = $this->getRedis($key);
        $this->multiRedis = false;

        return $this;
    }
public function onOneKeyServer($key)
    {
        $this->selectedRedis[] = $this->getRedis($key);
        $this->multiRedis = false;

        return $this;
    }
select one server according to the key

@param string $key cache key

@return $this
@throws Exception when no redis server available