php - 网站出现502 Bad gateway是怎么回事?

Question

网站一直出现502 Bad gateway 是怎么回事，是一个公司内部系统。chrome的console 报错是 Failed to load resource: net::ERR_CONNECTION_RESET，系统是 centos 6.5 阿里云服务器，环境是lnmp，请问这种报错一般该怎么排查呢，已经锁定了是下面这一段代码问题。但是我目前还没找到,php是5.5.36

if ($_REQUEST["field"]) {

            if (trim($_REQUEST['field']) == "all") {
                $field = is_numeric(trim($_REQUEST['search'])) ? 'name|origin|type|description|estimate_price|gain_rate|gain_cycle|sales_price|product_amount|total_price|estimate_income' : 'name|origin|type|description';
            } else {
                $field = trim($_REQUEST['field']);
            }

            $search = empty($_REQUEST['search']) ? '' : trim($_REQUEST['search']);
            $condition = empty($_REQUEST['condition']) ? 'is' : trim($_REQUEST['condition']);
            $field_date = M('Fields')->where('(is_main=1 and model="" and form_type="datetime") or (is_main=1 and model="business" and form_type="datetime")')->select();
            foreach($field_date as $v){
                if    ($field == $v['field']) $search = is_numeric($search)?$search:strtotime($search);
            }        
            if ($this->_request('state')){

                $state = $this->_request('state', 'trim');
                $address_where[] = '%'.$state.'%';

                if($this->_request('city')){
                    $city = $this->_request('city', 'trim');
                    $address_where[] = '%'.$city.'%';

                    if($this->_request('area')){
                        $area = $this->_request('area', 'trim');
                        $address_where[] = '%'.$this->_request('area', 'trim').'%';
                    }
                }

                if($search) $address_where[] = '%'.$search.'%';

                $params = array('field='.trim($_REQUEST['field']), 'condition='.$condition, 'state='.$this->_request('state','trim'), 'city='.$this->_request('city','trim'),'area='.$this->_request('area','trim'),'search='.$this->_request('search','trim'));
                if($condition == 'not_contain'){
                    $where[$field] = array('notlike', $address_where, 'OR');
                }else{
                    $where[$field] = array('like', $address_where, 'AND');

                }
            }else{
                $field_date = M('Fields')->where('is_main=1 and (model="" or model="business") and form_type="datetime"')->select();

                foreach($field_date as $v){
                    if($field == $v['field'] || $field == 'customer.create_time' || $field == 'customer.update_time') 
                        $search = is_numeric($search)?$search:strtotime($search);
                }

                if($field =="customer_id"){
                    $c_where['name'] = array('like','%'.$search.'%');
                    $customer_ids = M('Customer')->where($c_where)->getField('customer_id',true);
                    $where[$field] = array('in',$customer_ids);
                }else{
                    switch ($condition) {
                        case "is" : $where[$field] = array('eq',$search);break;
                        case "isnot" :  $where[$field] = array('neq',$search);break;
                        case "contains" :  $where[$field] = array('like','%'.$search.'%');break;
                        case "not_contain" :  $where[$field] = array('notlike','%'.$search.'%');break;
                        case "start_with" :  $where[$field] = array('like',$search.'%');break;
                        case "end_with" :  $where[$field] = array('like','%'.$search);break;
                        case "is_empty" :  $where[$field] = array('eq','');break;
                        case "is_not_empty" :  $where[$field] = array('neq','');break;
                        case "gt" :  $where[$field] = array('gt',$search);break;
                        case "egt" :  $where[$field] = array('egt',$search);break;
                        case "lt" :  $where[$field] = array('lt',$search);break;
                        case "elt" :  $where[$field] = array('elt',$search);break;
                        case "eq" : $where[$field] = array('eq',$search);break;
                        case "neq" : $where[$field] = array('neq',$search);break;
                        case "between" : $where[$field] = array('between',array($search-1,$search+86400));break;
                        case "nbetween" : $where[$field] = array('not between',array($search,$search+86399));break;
                        case "tgt" :  $where[$field] = array('gt',$search+86400);break;
                        default : $where[$field] = array('eq',$search);
                    }
                }
                $params = array('field='.trim($_REQUEST['field']), 'condition='.$condition, 'search='.$search );
            }
        }
        $order = empty($order) ? 'business.update_time desc' : $order;
        if(trim($_GET['act']) == 'excel'){
            if(vali_permission('business', 'export')){
                $dc_id = $_GET['daochu'];
                if($dc_id !=''){
                    $where['business_id'] = array('in',$dc_id);
                }
                $current_page = intval($_GET['current_page']);
                $export_limit = intval($_GET['export_limit']);
                $limit = ($export_limit*($current_page-1)).','.$export_limit;
                $businessList = $d_v_business->where($where)->order($order)->limit($limit)->select();println($businessList);
                session('export_status', 1);                
                $this->excelExport($businessList);
            }else{
                alert('error', L('HAVE NOT PRIVILEGES'), $_SERVER['HTTP_REFERER']);
            }
        }
        if($_GET['listrows']){
            $listrows = intval($_GET['listrows']);
            $params[] = "listrows=" . intval($_GET['listrows']);
        }else{
            $listrows = 15;
            $params[] = "listrows=15";
        }
        $list = $d_v_business->where($where)->order($order)->page($p.','.$listrows)->select();

        $count =  $d_v_business->where($where)->count();
        import("@.ORG.Page");
        $Page = new Page($count,$listrows);
        if (!empty($_GET['by'])) {
            $params[] = "by=".trim($_GET['by']);
        }
        
        $this->parameter = implode('&', $params);

        if ($_GET['desc_order']) {
            $params[] = "desc_order=" . trim($_GET['desc_order']);
        } elseif($_GET['asc_order']){
            $params[] = "asc_order=" . trim($_GET['asc_order']);
        }
        
        $Page->parameter = implode('&', $params);
        $this->assign('page', $Page->show());
        foreach($list as $key => $value){
            $list[$key]['owner'] = D('RoleView')->where('role.role_id = %d', $value['owner_role_id'])->find();
            $list[$key]['creator'] = D('RoleView')->where('role.role_id = %d', $value['creator_role_id'])->find();
            $list[$key]['customer_name'] = M('customer')->where('customer_id = %s',$value['customer_id'])->getField('name');
            $list[$key]['status_name'] = M('BusinessStatus')->where('status_id = %d', $value['status_id'])->getField('name');
            if($by == 'deleted') {
                $list[$key]["delete_role"] = D('RoleView')->where('role.role_id = %d', $value['delete_role_id'])->find();
            }
        }
        $d_role_view = D('RoleView');
        $this->listrows = $listrows;
        $this->role_list = $d_role_view->where('role.role_id in (%s)', implode(',', $below_ids))->select();
        $this->customer_list = M('customer')->where('owner_role_id in (%s)', implode(',', getSubRoleId()))->select();
        $this->assign('list',$list);
        $this->assign('count',$count);
        $this->search_field_array = getMainFields('business');
        $this->field_array = getIndexFields('business');
        $this->alert = parseAlert();
        $this->display();
    }

Answer 1

已经解决了，是$this->customer_list = M('customer')->where('owner_role_id in (%s)', implode(',', getSubRoleId()))->select();这一行代码造成的，因为Customer表数据太多做了多次查询

Answer 2

502就是php-fpm出问题了，高并发，无法接收请求了会报，还有就是php运行时间超时导致中断，看看php-fpm的设置

Answer 3

HTTP Status 502 （错误网关）服务器作为网关或代理，从上游服务器收到无效响应。解决办法可以参考这篇文章502是什么问题，希望对你有帮助。免费的php视频教程。