library/Rediska/Zend/Session/SaveHandler/Redis.php
public function write($id, $data)
    {
        try {
            $timestamp = time();
            $this->_set[$timestamp] = $id;
        } catch (Rediska_Connection_Exec_Exception $e) {
            $this->_deleteSetOrThrowException($e);
        }

        return $this->getRediska()->setAndExpire(
            $this->_getKeyName($id),
            $data,
            $this->getOption('lifetime')
        );
    }
public function write($id, $data)
    {
        try {
            $timestamp = time();
            $this->_set[$timestamp] = $id;
        } catch (Rediska_Connection_Exec_Exception $e) {
            $this->_deleteSetOrThrowException($e);
        }

        return $this->getRediska()->setAndExpire(
            $this->_getKeyName($id),
            $data,
            $this->getOption('lifetime')
        );
    }
Write session data

@param string $id
@param string $data
@return boolean