For Control-M version 9.0.00 or lower please refer to knowledge article 000102371
For Control-M version 9.0.18 the procedure to upgrade Tomcat is documented in knowledge article 000148756
For Control-M version 9.0.19 the procedure to upgrade Tomcat is documented in knowledge article 000271725
For Control-M version 9.0.20 the procedure to upgrade Tomcat is documented in knowledge article 000375017

 In Version 9.0.21.100 the tomcat version will be 9.0.68.
 In Version 9.0.21.300 the tomcat version will be 9.0.87.

Note: We strongly recommend that you test this procedure before applying any changes to a production environment.

1)   Download the latest available Tomcat minor version 9.0.xx binaries (where xx is greater than 54) from https://tomcat.apache.org/download-90.cgi  (Binary distribution Core, ZIP or tar.gz file). Upgrade to higher major version (10.x, 12.x ..) is NOT supported.
Extract the new Tomcat package to a newly created temporary source location on the Control-M/Enterprise Manager server:
       a. Windows: %EM_HOME%/Tomcat_Update
       b. UNIX: $EM_HOME/Tomcat_Update

2)    Stop all Control-M/Enterprise Manager components with the following command:
        Unix:  em ctl -mcs -all -C Config_Agent -cmd shutdown
        Windows: ctl -mcs -all -C Config_Agent -cmd shutdown
Make sure all components were stopped: ( All GUI Servers, GCS, Naming Service ( in 9.0.21.000), CMS, Configuration Agent (maintag), BIM, Forecast, Self Service, All Gateways, Archive Servers, Web Servers, All microservices)
              
         Note: The Enterprise Manager database should remain running!!

3)    Backup the Control-M/Enterprise Manager server “tomcat” directory (copy to different directory, eg tomcat_Original)
       a. Windows: %EM_HOME%/emweb/tomcat
       b. UNIX: $EM_HOME/etc/emweb/tomcat

4)    Rename the destination Control-M/Enterprise Manager server directory tomcat/bin and tomcat/lib to tomcat/bin-org and tomcat/lib-org.

5)    Copy the directories “bin” and “lib” from the temporary source location in Step 1 – tomcat to the destination directory "tomcat". 
Copy the files LICENSE, NOTICE, RELEASE-NOTES and RUNNING from the source location in Step 1 to the "tomcat" destination directories (overwrite the existing files)

6)  Change directory to the Backup "Tomcat" – eg tomcat_Original directory you created in Step 5 and copy
       a. %EM_HOME%/emweb/tomcat/tomcat_Original/lib/bmc-ctm-lib
            to “tomcat” destination directory 
            %EM_HOME%/emweb/tomcat/tomcat/lib/bmc-ctm-lib

         b. UNIX: $EM_HOME/ctm_em/etc/emweb/ltomcat_Original/lib/bmc-ctm-lib
             to "tomcat" destination directory
             $EM_HOME/ctm_em/etc/emweb/tomcat/lib/bmc-ctm-lib

7)   Delete all folders under destination directory "webapps"
                    run remove_webapps  (in Unix em remove_webapps)    
 
8)    Start all EM components
       a. Windows: Start Service "Control-MEM Configuration Agent"
       b. UNIX: em start_config_agent