This page describes steps to take before starting a Rhino Element Manager upgrade.
Note that there is no specific need to take a backup of the Tomcat installation prior to starting the upgrade. The first step
orca will perform when issued the
upgrade-rem command is to take a backup, which will be available at the end of the upgrade process.
Verify that REM is currently working on all hosts to be upgraded
On each host which is to be upgraded, log into the REM web application (or refresh the page if already logged in), and connect to one or more of your Rhino clusters within REM. This is to aid in troubleshooting connectivity issues after the upgrade, specifically to help distinguish between newly introduced issues and existing issues not related to the upgrade itself.
Note that when refreshing the REM web application, do a "hard refresh" (
Ctrl+F5 in most browsers) so that
the browser retrieves up-to-date information from the REM server rather than reloading from its cache.
Take note of all the web URLs used to connect to your existing instances of REM, or leave them open in browser tabs. This is to make it straightforward to check each instance of REM after the upgrade.
Ensure the REM hosts are configured as appropriate
Run the following command, passing in the hostnames of the REM hosts to be upgraded:
./orca --hosts <remhost1,remhost2,…> status
You should see REM status information about all the REM hosts specified, such as
REM: general = Server version: Apache Tomcat/8.5.29 Server built: Mar 5 2018 13:11:12 UTC Server number: 188.8.131.52 OS Name: Linux OS Version: 3.10.0-693.11.6.el7.x86_64 Architecture: amd64 JVM Version: 1.8.0_162-b12 JVM Vendor: Oracle Corporation catalina_base = /opt/tomcat/apache-tomcat-8.5.29 version = 184.108.40.206 plugins = sentinel-gaa-em-220.127.116.11 sentinel-volte-element-manager-18.104.22.168 catalina_home = /opt/tomcat/apache-tomcat-8.5.29 backup_dir = /home/rhino/rem-backup backups = (#1) 20181129-121625 contains REM:22.214.171.124 Plugins:sentinel-gaa-em-126.96.36.199,sentinel-volte-element-manager-188.8.131.52
Ensure the Apache Tomcat version, and path to the installation (listed under "catalina_home"), are correct.
Tomcat installation autodetection and specifying the installation path manually
In the vast majority of Tomcat installations these two variables point to the same location, namely the root of the
Tomcat installation under which REM has been installed. In this case it is only necessary to specify the
As mentioned in Additional parameters passed to
Alternate manual upgrade procedure for non-Tomcat based installations
If you do not see a section in the status output titled
REM, this is an indicator that this REM installation
may not be based on (a supported version of) Apache Tomcat. This
orca based procedure is only appropriate for
upgrading REM and its plugins when installed on top of Apache Tomcat version 7 and above.
For upgrading other types of REM installation, refer to the manual REM upgrade procedure.
Record the current time
orca backs up the current REM installation, it will move the backup to a directory with a timestamp based on the current time.
Make a note of the current time, in order to be able to locate this backup if needed.
Verify disk space
Verify the disk space on the REM hosts to be upgraded, by running the
df command on each host using
./orca --hosts <remhost1,remhost2,remhost3,…> run "df -h"
Ensure there is at least 200 megabytes of free disk space. Refer to this section if you need to clean up old backups in order to free disk space.