System
Q1 - What environment variables does the system use, and
what does it use them for ?
Q2 - Can I run collaborative sessions between users using
IRIS Explorer on different versions of UNIX ?
Modules
Q3 - What happens when I Duplicate a
collaborative module?
Q4 - What happens when I Replace a collaborative
module?
Q5 - Why can't I get MSharePointer to create a
pointer?
Server
Q6 - When attempting a collaborative session with another
user, we both get our systems connected to the COVISA Server, but no data
seems to pass.
Q7 - When attempting a dynamic
collaborative session, I get error messages telling me that explorer could
not start a particular module, even though my collaborator has one.
Q8 - Sometimes when we run a collaborative
session I get data as soon as I join the session, and other times my
collaborator has to send it to me.
A number of environment variables can be used to ease the setting up of
a collaborative session.
-
COVISA_CENTRAL_PORT - this should be set to the port number that the
COVISA Server
is using. Some port numbers are reserved and are not available at the user
level, the port number that we typically use is 5127; this default
value is set when IRIS Explorer is installed.
-
COVISA_CENTRAL_MACHINE - this should be set to the machine name where the
COVISA Server is running. It should be set in the form:
csindy12.leeds.ac.uk
-
USER - this sets the username widget on the MServer module and contains the
name used to identify a collaborator in the session. It is
often set by default by UNIX command shells. If this is not the case
then this variable may be explicitly set by the user using the
appropriate command for their chosen shell. For the csh and tcsh shells it
would be: setenv USER <username> before starting IRIS Explorer.
The MServer module picks up this information and uses it as default values
for some of its widgets. These can be altered at run time using the module
control panel. These values are particularly useful when creating collaborative
applications, or if the COVISA Server is always run at a default location.
The COVISA Server, by default, uses the COVISA_CENTRAL_PORT variable to
set its port number. This can be changed by using the
-port <portnumber>
command line argument when running the COVISA Server from a command shell.
See the description of the COVISA Server for more details.
The COVISA system, like the rest of IRIS Explorer,
is completely heterogenous. This means that sessions can be conducted not only
between users on different versions of UNIX, but also between users on UNIX
and Windows platforms.
When a module is duplicated (using the duplicate option from the popup
menu on the module), the effect varies depending on the current state of
the module. If it had not been initiated into the collaborative session
(by pressing the Initiate button) then the duplicated module automatically
joins the collaborative session and forms a new group. If it had been initiated
and was already a group member, then the duplicate appears to be a second
member of the same group. The COVISA Server will not allow more than a single
member of a group by one collaborator, and will eventually kill the duplicate
module (usually when it attempts to become connected for the first
time)
When you replace a collaborative module (using the replace option from
the popup menu on the module), it deletes the old module and starts a new
one. When this module is enabled it initiates itself into the collaborative
session and start a new group (i.e. it will have a different group
number and hence belong to a different group). This happens irrespective
of whether the module had previously been initiated or not. See Step 3 - Starting a Collaborative Module
for a detailed description of starting up a collaborative module.
The MSharePointer module's Output port should be wired to the Render module's
Input port, and the Render module's Pick port should be wired to Input
port of MSharePointer. The Render module then needs to be set into the
appropriate mode.
Although both parties have successfully connected to a COVISA Server, it
sounds like you have connected to different servers. For data to be passed
between collaborators, they all have to be connected to a single
COVISA Server. See Step 1 - Start a COVISA
Server for a detailed
description of how to start up a collaborative session.
For a collaborative session to work correctly, the COVISA module suite
must be installed on all collaborator's machines, with the modules
appearing in the librarian of each collaborator. Also, any other user written
modules that need to be used within the session should be installed locally
for each collaborator. The system is not currently capable of downloading
module code at run time.
The COVISA Server can be run in one of two different modes:
-
Store and Foreward (default mode) - in this mode the server keeps a copy
of the last shared data object passed to it for each collaborative group.
When a collaborator joins late, a copy of any stored data is automatically
passed on.
-
Pass - in this mode the server merely passes data to collaborators who
are currently members of the session. No data is stored at the server.
For a more detailed description see
Step 1 - Start a COVISA Server.