Dear all,
The architecture of our system is in here http://water.ee.nsysu.edu.tw/~jianhong/.
We have two LAS servers ( maybe 4 LAS servers in the further.
) and one load balance server, but the sister server is not yet
now.
In LAS A and LAS B, we installed all packages individually. (
includes UI server and Data server, MySQL, Ferret ... )
But the two LAS servers share a metadata database,
that is,
we only have to maintain one XML configuration files (
las.xml, ui.xml, operations.xml, options.xml and all datasets XML files )
in LAS A.
After we execute "genLas.pl" on LAS A, the metadata
database will be refreshed.
So, no matter the users connect to LAS A or LAS B,
they will get the same content on their browser and get correct
output.
( We directly connect to LAS A or LAS B, do
not through the sister server now)
Before I write this letter, we consider this archetcture
is available.
Unfortunately, there is a problem occurred.
In the "las.xml", it sets the url of Data server as following
lines.
<operations url=""http://172.16.66.74/las-bin/LASserver.pl">http://172.16.66.74/las-bin/LASserver.pl">
&operations; &insitu_operations; </operations> This means if a user connect to LAS A, the UI server of
LAS A will dispatch the XML request to the Data server of LAS A.
But if the user connect to LAS B, the UI server of LAS B will
also dispatch the XML request to the Data server of LAS A, rather than LAS
B.
It results in the Data server of LAS A is very busy, but the
Data server of LAS B is always idle.
We attempt to modify the url as http://127.0.0.1/las-bin/LASserver.pl.
Although this lets no Data server be idle, but the user
can't get the output,
the output window will tell user that it can't find
the output file in local machine.
We also attempt to modify the url as load balance
server's IP, that is, url=""
href="">http://172.16.66.73/las-bin/LASserver.pl.
but it is not work, after I select view, output, region and
then click "Next", the error message of java occurred.
Maybe the reason is that the configuration of CVS of load
balance server is not setting well, we will continue try
it.
Another solution is every LAS server maintain an individual
metadata database and individual XML configuration files.
It is the worst solution.
We think after sister server is ready, it may exist
many problems.
Does anyone has any suggestion for this problem? or for this
architecture?
Thanks very much.
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