D Oracle Exadata System Software Accessibility Recommendations

Oracle Exadata System Software includes tools such as dcli and cellcli that you can run from the command line. This section provides some tips on using screen readers and screen magnifiers with these tools.

D.1 Tips on Using Screen Readers and Braille Displays

Examples of screen readers include JAWS, SuperNova, NVDA, and Window-Eyes. Each of these provides text-to-speech output and supports braille displays.

Note:

Window-Eyes is now a part of ZoomText Fusion by Ai Squared.
  • Use a character mode based terminal such as Putty or Cygwin. Do not use an X-Windows-based VNC.

  • For screen reader users, we recommend installing "screen" in order to get multiple session support. The Linux based screen program allows for multiple sessions in different windows. You can access each session with keyboard based commands, for example, Ctrl-a. Screen allows you to detach or re-attach to a given window session. Like VNC, if you get disconnected when running Oracle ExaCHK, or patchmgr, or other program, you can re-attach to and resume that session.

    The screen package is not installed by default on Exadata. You will need to install it using yum. See the "How To Use Linux Screen" tutorial at https://www.rackaid.com/blog/linux-screen-tutorial-and-how-to/ for details.

  • In the settings of the terminal software, set the cursor type to "block" cursor, not blinking or flashing.

  • The output of the commands can generate a significant amount of information and might spill off the terminal window, and the virtual window or braille display. For example, the following command can generate a long alert history output:

    dcli -g cell_group -l root cellcli list alerthistory
    

    To display the output one screen-full at a time, pipe the output through the more command, as in the following:

    dcli -g cell_group -l root cellcli list alerthistory | more
    

    You can then use the space bar key to page through the output.

  • When exachk or dbnodeupdate.sh is launched interactively, do not pipe its output to the more or page commands. As it runs, it displays informational messages on the terminal. The messages pause when exachk requires user input, then resume after input is received. Important messages, user input, errors, and check results are logged in various files. The results from exachk are written to an HTML report. All you need to do is to transfer the HTML report to a computer that runs your assistive technology and open the HTML report in a browser that you can access with your assistive technology.

  • If you are running the patchmgr utility, and it is performing a task that takes some time to complete, the output displays a "spinner" and a countdown clock. The "spinner" cycles through the \, |, and / characters in-place, and the countdown clock is updated periodically. When the task is done, the output displays a "success" or "error" message, depending on the outcome. The output messages are also logged in a log file.

  • A few recommended screen reader settings include the following (JAWS is used here just as an example):

    • Set the JAWS cursor to "All". Use the key combination of Insert + s until you hear "All".

    • You may need to turn off virtual cursor. If you are using JAWS, you can do this using the key combination of Insert + z.

    • Use the virtual window to capture text. If you are using JAWS, you can do this using the key combination of Insert + Alt + w.

D.2 Tips on Using Screen Magnifiers

Examples of screen magnifiers include ZoomText, MAGic, and SuperNova.

  • Screen magnifiers can support both character-based terminals and X-Window-based VNC.

  • If you are using the screen reader function of the screen magnifier (ZoomText screen reader), then you should use a character-based terminal as described above.

  • If you are using a VNC, decide your preference for a window display, for example, TWM or ICE. A display setting for ICE can be done with the following:

    vncserver -geometry 1600x950 :2
    

    1600x950 specifies the display size, and :2 specifies the VNC display number.

D.3 Tips on Using Exawatcher Charts

Exawatcher is an Exadata specific tool that collects performance data from Exadata storage cells.

The data collected by Exawatcher can be graphed and presented in web pages. The web pages are based on Oracle JavaScript Extension Toolkit (JET), HTML and some use of ARIA. The Exawatcher pages can present charts which can be navigated using only a keyboard.

D.4 Oracle Exadata Deployment Assistant (OEDA) Web interface Accessibility

The OEDA Web interface conforms with the Web Content Accessibility Guidelines version 2.0 at the AA level (WCAG 2.0 AA).

The OEDA Web interface was built using Oracle JET, which provides support for:

  • Keyboard and touch navigation

    Oracle JET components follow the Web Accessibility Initiative - Accessible Rich Internet Application (WAI-ARIA) guidelines. You can find the Oracle JET hotkey information at Oracle JavaScript Extension Toolkit (JET) Keyboard and Touch Reference.

  • Zoom

    Oracle JET supports browser zooming up to 200%. For example, on the Firefox browser, you can choose View, then Zoom, and then Zoom In.

  • Screen reader

    Oracle JET supports screen readers such as JAWS, Apple VoiceOver, and Google Talkbalk by generating content that complies with WAI-ARIA standards, and no special mode is needed.

  • Oracle JET component roles and names

    Each component has an appropriate role, such as button, link, and so on, and each component supports an associated name (label), if applicable.

  • Sufficient color contrast

    Oracle JET provides the Alta theme which is designed to provide a luminosity contrast ratio of at least 4.5:1.

D.5 Running the Java-based Oracle Exadata Deployment Assistant on Windows

Oracle Exadata Deployment Assistant (OEDA) is a standalone Java-based application that runs under its own JRE. It is used to gather user input for all of the required configuration for deploying a new Exadata Database Machine. The latest Java-based release of OEDA ships with version 8 of the JRE, which has support for Java Access Bridge and assistive technology software such as JAWS, ZoomText, and others.

  1. Make sure the Java Access Bridge is enabled in Windows using the "Ease of Access" from the Windows Control Panel.

    Follow the instructions in Enabling and Testing Java Access Bridge in the Java SE documentation.

  2. Download the latest release of OEDA from Oracle Exadata Deployment Assistant Downloads on Oracle Technology Network.
  3. Follow the OEDA documentation for further usage and details.