4个sofa进程同时挂掉

今天在压测的时候，发现有个情况
4台server 挂在nginx域名下面
sofa server作为http server
某一时刻，4个server全挂了，也没产生core文件

问下，什么情况下，server会同时挂掉，是协议不兼容么
我理解的，如果协议不兼容，sofa会直接扔掉或者报错的

Start by reproducing the reported load-test setup: four servers behind an nginx domain, with sofa-pbrpc acting as the HTTP server. Check the server logs and core-dump configuration when all four processes exit; the issue provides no named source files or tests. Done means identifying a reproducible cause and documenting the conditions that trigger the simultaneous failures.

Written by the indexing model from the issue text.