Troubleshooting

The Windows service or Linux daemon won’t start

By default, the UAS binds to port 38001 and the UAS management console binds to port 38000. If these ports are already in use, please change the default ports in the configuration files.

If the Management Console appears to be running but the UAS Launcher has failed to start, this is probably due to Python not being present in the Windows path settings. Please check your environment settings and ensure that Python is present. If this is the problem, it will also appear in the Windows event logs.

On Windows, if it seems that no port is available for the Management Console to bind to (whatever port you try results in an error), it may be that your virus checker (in particular ESET NOD32) is blocking Python. The Management Console is built on CherryPy which uses Python. To solve this issue you might have to configure the virus checker to ignore Python.

To run the Windows services you must have administrative privileges, please ensure that you are logged in as an administrator when installing the a MSI package.

To run Linux daemons you must be root.

My browser can’t access the UAS management console

The UAS management console is viewed via a web browser at localhost:38000. If you are using a proxy server please ensure that you bypass it for local addresses.

The UAS is very slow

On some Linux distributions the default stack size per thread is eight megabytes. If the UAS is going to run hundreds of applications the amount of memory used can quickly become too large and the UAS will become sluggish. It is therefore important to reduce the stack size per thread. This can be done using the ulimit command, e.g.:

ulimit -s 256

The UAS runs out of file descriptors

On Linux systems, the typical default number of files descriptors may not be sufficient for the number of concurrent applications you want to run. It is recommended that you change the limit, for example:

ulimit -n 65536

The UAS management console can’t upload applications

The Management Console application requires write permission in the UAS_Launcher subdirectories.

Uploading an application results in an import error

It might be that you have illegal characters in the file name. Python will not allow the file name to begin with a digit, it will also not allow the - in a file name.

If you are running the UAS as a Windows service. The Windows service includes a private version of the Python library. When an application is uploaded to the UAS it might look at the private Python library for the modules it wants to import, and one of them might not be available. The solution to this is to append the path to your local Python distribution in the application you are uploading.

For example:

import sys, os
sys.path.append(os.path.abspath('C:/Users/<username>/AppData/Local/Programs/Python/Python36/Lib'))
import xml.dom.minidom

How do I manually control the Windows services

If you installed the UAS package using the Windows EXE file, under normal circumstances the two UAS Windows services (UAS_Launcher and UAS_Management_Console) will have been automatically installed and started.

Should you need to manually stop, start or restart the UAS_Launcher or UAS_Management_Console services, this can be achieved with any of the following methods:

  • Using the Windows Services Application

    To invoke the Windows Services Application, press the Windows+R keys on your keyboard to open the Run window, then type “services.msc” and hit Enter or press OK. Right clicking on the UAS_Launcher or UAS_Management_Console services shown in the list of services will display the control options available.

  • Using the SC Windows command line tool

    To view the usage instructions for the SC tool, open a Windows command prompt, type sc and hit Enter.

    Examples of how SC can be used to stop and start the UAS services:

    • sc stop UAS_Launcher

    • sc stop UAS_Management_Console

    • sc start UAS_Launcher

    • sc start UAS_Management_Console

  • Running the UAS_Launcher and/or UAS_Management_Console executables with arguments

    To control the UAS Launcher, open a Windows command prompt and navigate to the UAS package installation directory where UAS_Launcher.exe resides. You can then run the following:

    • UAS_Launcher install to install the Windows service

    • UAS_Launcher start to start the Windows service

    • UAS_Launcher stop to stop the Windows service

    • UAS_Launcher remove to remove the Windows service

    • UAS_Launcher debug to run the UAS as a console application.

    Similarly, to control the UAS Management Console, open a Windows command prompt and navigate to the UAS package installation directory where UAS_Management_Console.exe resides. You can then run the following:

    • UAS_Management_Console install to install the Windows service

    • UAS_Management_Console start to start the Windows service

    • UAS_Management_Console stop to stop the Windows service

    • UAS_Management_Console remove to remove the Windows service

    • UAS_Management_Console debug to run the Management Console as a console application.

I have moved or deleted a file from my media store but it is still there

Please read the section about media files which describes some of the characteristics of the media store on cloud.aculab.com.