function set($key, $value, $expire = 0)
{
$in['ckey'] = $key;
if (is_array($value)) {
$value = serialize($value);
}
$in['cvalue'] = $value;
if ($expire == 0) {
$in['expire'] = $expire;
} else {
$in['expire'] = time() + $expire;
}
$in['sid'] = $this->shard_id;
$this->model->put($in);
}