Question & Answer
Question
How to start DB2 Alphablox remotely and have it run in the background on a UNIX host using XVFB server.
Answer
To start DB2 Alphablox in a UNIX environment, DB2 Alphablox must start its graphics package (for charting) at the same time as starting the rest of the server components. This is because the DB2 Alphablox server-side Java graphics rendering requires the presence of a windowing system (X11 under UNIX). When attempting to start DB2 Alphablox via a telnet session, the telnet session does not use any windowing system at all, therefore AAS will be unable to start its graphics package.
The windowing system is required for startup because the X11 implementation of the DB2 Alphablox graphics package creates a graphics context to establish things like color palette size, color names, etc. Without a display to ask, these questions cannot be answered (in X terms), so the graphics package cannot start, and neither can DB2 Alphablox. Hence, there must be a context in which the software runs; that is, an X host. One way to provide this context is by a virtual X buffer (i.e. "vxb" ) so that AAS can in fact be started from a telnet session.
Installing the XVFB
This section describes how to install the software for the XFVB on various versions of AIX.
- AIX 4.3
The XVFB for AIX 4.3 is installed from the following fileset:
U454163 - OpenGL.OpenGL_X.dev.vfb.04.03.0000.0000
U454162 - X11.vfb.04.03.0000.0000
Two PTFs are needed to fix a window resizing problem, but because they are not available, you must migrate to AIX 4.3.1 or later to use the XVFB with AIX 4.3 .
If the PTF U452591 is installed, CATweb Navigator Version 1 runs successfully.
U452591 - OpenGL.OpenGL_X.rte.soft.4.3.0.1
- AIX 4.3.1
The XVFB for AIX 4.3.1 is installed from the AIX 4.3.1 product CDs. Install the following filesets:
OpenGL.OpenGL_X.dev.vfb.04.03.0001.0000
X11.vfb.04.03.0001.0000
Two PTFs are needed to fix a window resizing problem and are available on fixdist:
U456096 - OpenGL.OpenGL_X.dev.vfb.4.3.1.1
U456079 - OpenGL.OpenGL_X.rte.soft.4.3.1.1
- AIX 4.3.2
The XVFB for AIX 4.3.2 is installed from the AIX 4.3.2 product CDs. Install the following filesets:
OpenGL.OpenGL_X.dev.vfb.04.03.0002.0000
X11.vfb.04.03.0001.0000
AIX 4.3.3
The XVFB for AIX 4.3.3 is installed from the AIX 4.3.3 product CDs. Install the following filesets:
OpenGL.OpenGL_X.dev.vfb.04.03.0003.0000
X11.vfb.04.03.0003.0000
To get 8-bit pseudocolor support, install the following PTF, which is available on fixdist:
U474006 - 4330-06 Recommended Maintenance for AIX 4.3.3
AIX 5.1
The XVFB for AIX 5.1 is installed from the AIX 5.1 product CDs. Install the following filesets:
OpenGL.OpenGL_X.dev.vfb.05.01.0000.0000
X11.vfb.05.01.0000.0000
Starting the XVFB
The XVFB is loaded into the X server with the -vfb flag:
/usr/bin/X11/X -force -vfb -x abx -x dbe -x GLX :n &
where n is the display number you wish to have associated with this instance of the XVFB. This starts the X server without using any installed graphics adapter and loads the OpenGL extensions to the X server.
The xinit command can also be used, which starts both the X server and the window manager:
/usr/bin/X11/xinit -- -force -vfb -x abx -x dbe -x GLX :n &
The -vfb flag can also be added to the EXTENSIONS line in your .xserverrc file.
To have the XVFB effective at system boot, have the system administrator add the following entry in the /etc/inittab file:
xvfb:2:respawn:/usr/bin/X11/X -force -vfb -x abx -x dbe -x GLX :n > /dev/null
This entry causes the X server to start at system boot time and restart automatically if the server ever exits or dies.
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Document Information
Modified date:
16 June 2018
UID
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