에러 유도  1.  > 만약, 1번 서버 = 기준  1번 서버 선 종료 후 2번 서버 종료 > 2번 서버가 기준이 됨 > 이 상태에서 1번 서버 systemctl start mariadb > [ERROR] WSREP: failed to open gcomm backend connection: 110: failed to reach primary view: 110 (Connection> at /home/buildbot/buildbot/build/gcomm/src/pc.cpp:connect():160 [ERROR] WSREP: /home/buildbot/buildbot/build/gcs/src/gcs_core.cpp:gcs_core_open():222: Failed to open back> [ERROR] WSR..