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Running multiple servlet UIs

Question:




How can I run multiple LAS UI servlets from 
  a single Tomcat installation?



Explanation:



If you have a need, like we do, to run multiple LAS servers on a single computer 
  you will probably want to avoid running a separate Tomcat server with each LAS. 
  Each time you configure another LAS, the LAS configuration process instructs 
  you to start up another Tomcat server to handle the user interface (UI) for 
  that LAS. This can lead to a large number of java processes running as each 
  Tomcat server starts up several daemon processes to listen to the port assigned 
  to it.


For infrequently used LAS interfaces it is better to use only one Tomcat server 
  and have it serve up several different LAS UIs. Just as a single Apache web 
  server handles requests to several different LAS data servers.


A full explanation of the separate UI and data servers is given here.


If you are going to have more than one LAS installation at your site, each installation 
  should be in its own directory. In each directory you will configure a unique 
  LAS. The las/configure.pl 
  script in each directory does the following:


    
  
  1. check for the availability of all needed software 
    2. 
  
  2. add servlet port and web address information to various configuration files
    3. 
  
  3. create an las database table
    4. 
  
  4. create various directories and scripts from their '.in' 
    files
    5. 
  
  5. run las/xml/perl/genLas.pl 
    to populate the las database table with info from the 
    las/server/*.xml files
    6. 
  
  6. update the las.war 
    file with las properties and copy it to the las_servlet/jakarta/webapps 
    directory.
    7. 



It is the las.war 
  file created in step 6. that contains all the information needed by Tomcat to 
  server up that LAS's UI.


Solution:



The configure.pl file 
  in the top level directory for each LAS contains the following:


#
# Home of TOMCAT server (should be configurable in future)
#
my $JAKARTA_HOME = "las_servlet/jakarta";


To have multiple LAS installations share a single Tomcat installation you just 
  need to modify this variable to point to the appropriate location in your Tomcat 
  installation. Then rerun the configure script for that LAS and restart the Tomcat 
  server. 





Jonathan Callahan: Jonathan.S.Callahan@noaa.gov

  Last modified:February 13, 2003