Selenium hover action with IE doesn't work if RDP never connected to Jenkins slaves - windows

Question

We create a bunch of windows Jenkins slaves on Amazon EC2, and make them autologon after they are provisioned.
Once logged on, we use connect the slaves back to master via java web start by execute "ps", with all of this, we can run selenium perfectly with IE except we can't get a higher resolution than 1024*768. We got screenshot, we can see the browser running on the GUI if connected with RDP, just like running on a physical PC.
But a flaw is that, the hover action doesn't work on IE unless we connect to the slave through remote desktop one time before the test starts, just connect once, nothing else, I can even close the RDP session.
I guess something triggered by the RDP connection, just can't figure out what is that.

Answer 1

You can try to adapt your test scripts to have them make an RDP connection before you start your tests, if there is none. This is the code I used for one of our projects to ensure an RDP connection is active:
REM check if user has an RDP session. Will store the session ID of the user in the SESSION variable
call :getsession computername username SESSION
if "%SESSION%" EQU "" (
REM initiate an RDP connection to 'computername', wait, and disconnect by killing the process
mstsc.exe /v:computername & ping -n 5 1.1.1.1 & taskkill /F /IM mstsc.exe
)
REM check again the session
call :getsession computername user SESSION
if %SESSION% NEQ "" (
echo start your tests
)
:getsession
for /F "tokens=1,2,3,4" %%i in ('query session /SERVER:%1 ^| findstr %2') do if %%j EQU %2 (SET %3=%%k) else (SET %3=%%j)
goto :eof
Note that the automatic connection will only be made if you save credentials on the machine from which you start the remote desktop:
cmdkey /generic:computername /user:rdp_username /pass:rdp_password
After executing this once the mstsc.exe will be able to connect to the machine without user interaction.