Configuring Fault Tolerance
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Configuring Ranger Admin HA Without SSL

Set up the load-balancer and enable Ranger Admin on an Ambari-managed cluster.

  1. Use SSH to connect to the cluster node where you will set up the load-balancer. In this procedure, we use the IP address
  2. Use the following command to switch to the /usr/local directory:
    cd /usr/local
  3. Download the httpd file and its dependencies (apr and apr-util):
  4. Extract the contents of these files:
    tar -xvf httpd-2.4.16.tar.gz
    tar -xvf apr-1.5.2.tar.gz 
    tar -xvf apr-util-1.5.4.tar.gz
  5. Run the following commands to move apr and apr-util to the srclib directory under httpd:
    mv apr-1.5.2/ apr
    mv apr httpd-2.4.16/srclib/ 
    mv apr-util-1.5.4/ apr-util
    mv apr-util httpd-2.4.16/srclib/
  6. Install PCRE (Perl-Compatible Regular Expressions Library):
    yum install pcre pcre-devel

    Here we are using yum install, but you can also download the latest bits from

  7. Install gcc (ANSI-C Compiler and Build System):
    yum install gcc
  8. Run the following commands to configure the source tree:
    cd /usr/local/httpd-2.4.16
  9. Run the following command to make the build:
  10. Run the install:
    make install
  11. Run the following commands to confirm the preceding configuration steps:
    cd /usr/local/apache2/bin
    ./apachectl start
    curl localhost

    This should return:

    <html><body><h1>It works!</h1></body></html>
  12. Run the following commands to create a backup conf file.
    cd /usr/local/apache2/conf
    cp httpd.conf ~/httpd.conf.backup
  13. Edit the httpd.conf file:
    vi /usr/local/apache2/conf/httpd.conf

    Make the following updates:

    • If you are not running the load-balancer on the default port 80, change the default listening port in line Listen 80 to match the port setting.

    • Un-comment the following module entries (remove the # symbol at the beginning of each line):

      LoadModule proxy_module modules/
      LoadModule proxy_http_module modules/
      LoadModule proxy_ajp_module modules/
      LoadModule proxy_balancer_module modules/
      LoadModule slotmem_shm_module modules/
      LoadModule lbmethod_byrequests_module modules/
      LoadModule lbmethod_bytraffic_module modules/
      LoadModule lbmethod_bybusyness_module modules/
    • Update the ServerAdmin email address, or comment out that line.

    • At the end of the httpd.conf file, add the following line to read the custom configuration file:

      Include conf/ranger-cluster.conf
  14. Create a custom conf file:
    vi ranger-cluster.conf

    Make the following updates:

    • Add the following lines, then change the <VirtualHost *:88> port to match the default port you set in the httpd.conf file in the previous step.

      # This is the Apache server configuration file providing SSL support.
      # It contains the configuration directives to instruct the server how to
      # serve pages over an https connection. For detailing information about these
      # directives see <URL:>
      # Do NOT simply read the instructions in here without understanding
      # what they do.  They're here only as hints or reminders.  If you are unsure
      # consult the online docs. You have been warned.
      #Listen 80
      <VirtualHost *:88>
              ProxyRequests off
              ProxyPreserveHost on
              Header add Set-Cookie "ROUTEID=.%{BALANCER_WORKER_ROUTE}e; path=/" env=BALANCER_ROUTE_CHANGED
              <Proxy balancer://rangercluster>
                      BalancerMember loadfactor=1 route=1
                      BalancerMember loadfactor=1 route=2
                      Order Deny,Allow
                      Deny from none
                      Allow from all
                      ProxySet lbmethod=byrequests scolonpathdelim=On stickysession=ROUTEID maxattempts=1 failonstatus=500,501,502,503 nofailover=Off
              # balancer-manager
              # This tool is built into the mod_proxy_balancer
              # module and will allow you to do some simple
              # modifications to the balanced group via a gui
              # web interface.
              <Location /balancer-manager>
                      SetHandler balancer-manager
                      Order deny,allow
                      Allow from all
             ProxyPass /balancer-manager !
             ProxyPass / balancer://rangercluster/
             ProxyPassReverse / balancer://rangercluster/

    The URLs listed in the BalancerMember entries are the IP addresses of the Ranger Admin hosts. In this example, the Ranger Admin host addresses are:
  15. Run the following commands to restart the httpd server:
    cd /usr/local/apache2/bin
    ./apachectl restart

    If you use a browser to check the load-balancer host (with port) as specified in the BalanceMember entries in the ranger-cluster.conf file, you should see the Ranger Admin page.

  16. Enable Ranger Admin HA using Ambari. On the Ambari dashboard of the first Ranger host, select Services > Ranger, then select Service Actions > Enable Ranger Admin HA to launch the Enable Ranger Admin HA Wizard.
  17. On the Get Started page, enter the load-balancer URL and port number (in this example,, then click Next.
  18. On the Select Hosts page, confirm the host assignments, then click Next.
  19. Check the settings on the Review page, then click Next.
  20. Click Complete on the Install, Start, and Test page to complete the installation.
  21. When the installation is complete, the Ranger Admin instances are listed on the Ranger Summary page. Select Actions > Restart All Required to restart all services that require a restart.

    For Oracle, clear the Setup DB and DB user check box under "Advanced ranger-env" to avoid DB setup.

  22. To test the load-balancer and Ranger HA configuration, select Ranger > Service Actions > Stop on one of the Ranger hosts.
  23. Use a browser to check the load-balancer host URL (with port). You should see the Ranger Admin page.