Veyon Community Forum
    • Register
    • Login
    • Search
    • Categories
    • Recent
    • Tags
    • Popular
    • Users
    • Groups

    veyon-server doesn't start (Qt::AA_ShareOpenGLContexts must be set before QCoreApplication)

    Help & Troubleshooting
    5
    12
    531
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as topic
    Log in to reply
    This topic has been deleted. Only users with topic management privileges can see it.
    • W
      white_rabbit last edited by

      Hi.
      When I check the status von veyon on an Ubuntu 20.04 client I get this:

      sudo systemctl status veyon
● veyon.service - Veyon Service
     Loaded: loaded (/lib/systemd/system/veyon.service; enabled; vendor preset: enabled)
     Active: active (running) since Thu 2021-05-27 11:09:42 CEST; 26min ago
       Docs: man:veyon-service(1)
   Main PID: 1519 (veyon-service)
      Tasks: 9 (limit: 9404)
     Memory: 46.3M
     CGroup: /system.slice/veyon.service
             ├─ 1519 /usr/bin/veyon-service
             └─81496 /usr/bin/veyon-worker {8e997d84-ebb9-430f-8f72-d45d9821963d}

Mai 27 11:09:42 raum1-pc systemd[1]: Started Veyon Service.
Mai 27 11:09:42 raum1-pc veyon-service[1519]: Attribute Qt::AA_ShareOpenGLContexts must be set before QCoreApplication is >

      I'm not sure but is it possible (as a consequence of the last error) that veyon-server doesn't start?
      Thank you?

      1 Reply Last reply Reply Quote 0
      • tobydox
        tobydox last edited by

        This is just a warning which has been fixed in Veyon 4.5.6 but unfortunately it's not related to the server start problem 😞

        Did you already try to enable advanced the "Write to logging system of operating system" option (https://docs.veyon.io/en/latest/admin/reference.html#logging) and change the log level to debug? You should then see the output of the veyon-server process in the veyon-service unit's journal. If the program catchsegv is in PATH, it will be used to dump a possible backtrace of the server if it crashes.

        W 1 Reply Last reply Reply Quote 0
        • W
          white_rabbit @tobydox last edited by white_rabbit

          @tobydox
          Hi. I enabled the Logfiles in Debug-Mode.
          Now I found this:

           /tmp]$ tail  VeyonService.log

2021-05-29T11:52:41.093: [INFO] LinuxServiceCore::startServer(): Starting server for new session "/org/freedesktop/login1/session/_32" with ID 0 at seat "/org/freedesktop/login1/seat/seat0"
2021-05-29T11:55:20.873: [ERR] LinuxServiceCore::startServer(): Can't start Veyon Server in Wayland sessions as this is not yet supported. Please switch to X11-based sessions!
2021-05-29T11:55:23.198: [DEBUG] PlatformSessionManager::closeSession(): Closing session 0 for platform session "/org/freedesktop/login1/session/_32"
2021-05-29T11:55:23.198: [INFO] LinuxServiceCore::stopServer(): stopping server for removed session "/org/freedesktop/login1/session/_32"
2021-05-29T11:55:35.946: [DEBUG] LinuxServiceCore::startServ

          When I observe the process veyon-service with catchsegv I found this:

          29/05/2021 12:12:03 Xinerama: number of sub-screens: 1
29/05/2021 12:12:03 Xinerama: no blackouts needed (only one sub-screen)
29/05/2021 12:12:03 

X11 MIT Shared Memory Attach failed:
  Is your DISPLAY=:0 on a remote machine?
  Suggestion, use: x11vnc -display :0 ... for local display :0

caught X11 error:
29/05/2021 12:12:03 deleted 32 tile_row polling images.
X Error of failed request:  BadAccess (attempt to access private resource denied)
  Major opcode of failed request:  130 (MIT-SHM)
  Minor opcode of failed request:  1 (X_ShmAttach)
  Serial number of failed request:  57
  Current serial number in output stream:  91

          And afterwards the same with veyon-server:

          2021-05-29T12:15:35.158: [DEBUG] VeyonCore::initSystemInfo(): "4.5.5" "fossa.my-domain.de" "linux" "5.8.0-53-generic" "Ubuntu 20.04.2 LTS" "ubuntu" "20.04"
2021-05-29T12:15:35.166: [ERR] VncServer::VncServer(): no VNC server plugins found!
2021-05-29T12:15:35.196: [DEBUG] [KLDAP] connection closed!
2021-05-29T12:15:35.196: [DEBUG] [KLDAP] ldap url: "ldap://server.my-domain.de:3268"
2021-05-29T12:15:35.197: [DEBUG] [KLDAP] setting version to: 3
2021-05-29T12:15:35.197: [DEBUG] [KLDAP] setting timeout to: 0
2021-05-29T12:15:35.197: [DEBUG] [KLDAP] setting security to: 1
2021-05-29T12:15:35.197: [DEBUG] [KLDAP] start TLS
2021-05-29T12:15:35.264: [DEBUG] [KLDAP] setting sizelimit to: 0
2021-05-29T12:15:35.264: [DEBUG] [KLDAP] setting timelimit to: 0
2021-05-29T12:15:35.264: [DEBUG] [KLDAP] initializing SASL client
2021-05-29T12:15:35.264: [DEBUG] [KLDAP] binding to server, bindname:  "<MY-SAMBA-DOMAIN>\\admin"  password: *****
2021-05-29T12:15:35.264: [DEBUG] [KLDAP] ldap_sasl_bind_s (simple)
2021-05-29T12:15:35.303: [DEBUG] FeatureWorkerManager::startUnmanagedSessionWorker(): Starting worker (unmanaged session process) for feature QUuid("{8e997d84-ebb9-430f-8f72-d45d9821963d}")
2021-05-29T12:15:35.304: [DEBUG] FeatureWorkerManager::sendMessageToUnmanagedSessionWorker(): User session likely not yet available - retrying worker start
2021-05-29T12:15:35.304: [DEBUG] VncProxyServer::start(): started on port 11100
2021-05-29T12:15:35.304: [DEBUG] VncServer::prepare():
2021-05-29T12:15:35.304: [DEBUG] VeyonCore::exec(): Running
2021-05-29T12:15:35.305: [DEBUG] VeyonCore::exec(): Exit
2021-05-29T12:15:35.305: [DEBUG] ComputerControlServer::~ComputerControlServer():
2021-05-29T12:15:35.305: [DEBUG] VncServer::~VncServer():
2021-05-29T12:15:35.305: [DEBUG] Logger::~Logger(): Shutdown
PluginManager::~PluginManager():
CryptoCore::~CryptoCore():
KLDAP: connection closed!

          Is this helpful?

          1 Reply Last reply Reply Quote 0
          • tobydox
            tobydox last edited by

            Can you try to add -noshm as additional custom x11vnc parameter in the advanced VNC server configuration?

            W S 2 Replies Last reply Reply Quote 1
            • W
              white_rabbit @tobydox last edited by

              @tobydox said in veyon-server doesn't start (Qt::AA_ShareOpenGLContexts must be set before QCoreApplication):

              -noshm

              Wow -- I think that's the solution! I just added this option and restarted the Client -- now "htop" shows a running veyon-server ... I can't test it in our productive environment at the moment but it looks good so far! Thank you!

              H 1 Reply Last reply Reply Quote 0
              • H
                hammergil @white_rabbit last edited by

                @white_rabbit where do you add this parameter? Is it in the Veyon configuration interface somewhere?

                tobydox 1 Reply Last reply Reply Quote 0
                • tobydox
                  tobydox @hammergil last edited by tobydox

                  The VNC server section is correct, make sure to enable advanced view in the menu and to select "Builtin VNC server":

                  noshm.jpg

                  H 1 Reply Last reply Reply Quote 0
                  • H
                    hammergil @tobydox last edited by

                    @tobydox the master computer is running Windows 10 and does not have an option for parameters. The built-in vnc is UltraVNC.
                    1f9424b3-5656-4fac-8922-44091538f68a-image.png

                    tobydox 1 Reply Last reply Reply Quote 0
                    • tobydox
                      tobydox @hammergil last edited by

                      @hammergil

                      Since the Linux-based student computers are affected, you have to make the configuration changes on them directly 😉

                      H 2 Replies Last reply Reply Quote 0
                      • H
                        hammergil @tobydox last edited by

                        @tobydox Great! That did it! Thanks for the help!

                        1 Reply Last reply Reply Quote 0
                        • H
                          hammergil @tobydox last edited by

                          @tobydox what does the parameter "-noshm" mean out of curiosity.

                          1 Reply Last reply Reply Quote 0
                          • S
                            stephanvaningen @tobydox last edited by

                            @tobydox nice. This solved an issue I've been struggling with for quite q few days:) thanks!

                            1 Reply Last reply Reply Quote 0
                            • First post
                              Last post
                            Powered by NodeBB | Contributors