Even PostgreSQL problem: expected authentication request from server, but received V

（ One ） The phenomenon

Some one Linux Virtual machine C++ The program could not connect PostgreSQL14 database ️
Report errors ：expected authentication request from server, but received v

The following phenomena were observed ：

1. The same program on the same host , Change local connection openGauss3.0.0 The database is normal .
2. On the same host Java The program can connect normally PostgreSQL14 database .
3. Other virtual machines / Other programs of the physical machine can be connected normally PostgreSQL14 database .

（ Two ） analysis

In fact, it took a long time to understand ……

Through the analysis of , The virtual machine is installed openGauss3.0.0 Server side .
Set up ：export LD_LIBRARY_PATH=$GAUSSHOME/lib:$LD_LIBRARY_PATH
Lead to C++ The program didn't find the Library PostgreSQL The library of , Instead, I found it by mistake openGauss The library of ,

（ 3、 ... and ） solve

• Don't put openGauss Add the Library Directory of LD_LIBRARY_PATH, however openGauss The server cannot be started .
• perform C++ Users of the program , And installation openGauss User separation of , Prevent interference with each other .