Methodology for troubleshooting problems (applicable to troubleshooting problems arising from any multi-party cooperation)

This methodology , It's my philosophy .
Here to share .
Can you understand , Look at personal savvy ！

Things are as follows ：
Partner , It's all about 4 Party team .
A Group ： The code development team .
B Group ： Our O & M personnel .
C Group ： Party A's network security team .
D Group ： The person in charge of the end-to-end system .

The main problem ：
We start from the server , request D Of the group url Interface , Always timeout.

experience ：
With the cooperation of our operation and maintenance personnel A The team checked for more than a month , In the absence of results , I took over the matter .
Judging from the past
I think of two ：
1、A Group code problem .
2、 Server network problems .

therefore , I aim at these two points , Write commands , Operation and maintenance execution , Check .
Final , The discovery is not a code problem .
however ,telnet IP port It can also be used .
That's for sure , It's not a network problem .

This is beyond my previous knowledge .
therefore , Asked our project director . There is another one in the middle WAF（Web Application Firewall）

therefore , From this breakthrough point , Described the troubleshooting process with the customer . Here we are WAF person in charge .
Again 2 God , To no avail .

however , This process , Our operation and maintenance personnel , Always self righteous to say , It's not the problem here , It's not a problem , It must be the problem there .
He roared firmly in the crowd ： It can't be us WAF problem .
9 It is certain that D Problems with group to end systems .

My judgment ：

however , O & M slapped me in the face , On the third day WAF After the team checks , Say it's your problem , Resolving .

Here we are told a truth ：
Before we find out the situation
Don't exclude anyone from responsibility , Don't insist on whose responsibility it is . So that we can check together
Once you exclude someone from responsibility , That group of people will definitely not take the initiative to check the problems
Once you decide who is responsible , It is likely to hit the face , and , Fewer people will participate in the investigation .
Neither of these approaches has a good result .

therefore , Before the situation is clear , Stir the water as muddy as possible , such , The people in it , They will examine themselves in private
Take the initiative to find out problems and be found out by others , That makes people feel very different .