To Configure Load Balancer 1

Before You Begin

• Contact your network administrator to obtain an available virtual IP address for the load balancer you want to configure.

  You must also know the IP address of the load balancer hardware, the URL for the load balancer login page, and a username and password for logging in to the load balancer application.

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  Note –

  The load balancer hardware and software used in the lab facility for this deployment is BIG-IP® manufactured by F5 Networks. If you are using different load balancer software, see the documentation that comes with that product for detailed settings information.

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• You must also have ready the IP addresses for Directory Server 1 and Directory Server 2.

  To obtain these IP addresses, on each Directory Server host, run the following command:

  ifconfig —a

1. Create a Pool.

   A pool contains all the backend server instances.

   1. Go to URL for the Big IP load balancer login page.

   2. Open the Configuration Utility.

      Click “Configure your BIG-IP (R) using the Configuration Utility.”

   3. In the left pane, click Pools.

   4. On the Pools tab, click the Add button.

   5. In the Add Pool dialog, provide the following information:

      Pool Name

      Example: directoryserver-pool

      Load Balancing Method

      Round Robin

      Resources

      Add the IP address of both Directory Server hosts. In this case, add the IP address and port number for DirectoryServer-1:1389 and for DirectoryServer-2:1389.

   6. Click the Done button.

2. Add a Virtual Server.

   If you encounter Javascript errors or otherwise cannot proceed to create a virtual server, try using Microsoft Internet Explorer for this step.

   1. In the left frame, Click Virtual Servers.

   2. On the Virtual Servers tab, click the Add button.

   3. In the Add a Virtual Server dialog box, provide the following information:

      Address

      xxx.xx.69.14 (for LoadBalancer-1.example.com )

      Service

      389

      Pool

      directoryserver-pool

   4. Continue to click Next until you reach the Pool Selection dialog box.

   5. In the Pool Selection dialog box, assign the Pool (DirectoryServer-POOL) that you have just created.

   6. Click the Done button.

3. Add Monitors

   Monitors are required for the load balancer to detect the backend server failures.

   1. In the left frame, click Monitors.

   2. Click the Basic Associations tab.

   3. Add an LDAP monitor for the Directory Server 1 node.

      Three columns exist on this page: Node, Node Address, and Service. In the Node column, locate the IP address and port number DirectoryServer–1:1389. Select the Add checkbox.

   4. Add an LDAP monitor for the Directory Server 2 node.

      In the Node column, locate the IP address and port number for DirectoryServer–2:1389 . Select the Add checkbox.

   5. At the top of the Node column, in the drop-down list, choose ldap-tcp .

   6. Click Apply.

4. Configure the load balancer for simple persistence.

   Simple persistence returns a client to the same node to which it connected previously. Simple persistence tracks connections based only on the client IP address.

   1. In the left frame, click Pools.

   2. Click the name of the pool you want to configure.

      In this example, directoryserver-pool.

   3. Click the Persistence tab.

   4. On the Persistence tab, under Persistence Type, select the Simple.

   5. Set the timeout interval.

      In the Timeout field, enter 300 seconds.

   6. Click Apply.

5. Verify the Directory Server load-balancer configuration.

   1. Log in as a root user to the host of each Directory Server.

   2. On each Directory Server host, use the tail command to monitor the Directory Server access log.

      # cd /var/opt/mps/serverroot/slapd-am-config/logs

      # tail -f access

      You should see connections to the load balancer IP address opening and closing. Example:

      [12/Oct/2006:13:10:20-0700] conn=54 op=-1 msgId=-1 — 
      fd=22 slot=22 LDAP connection from xxx.xx.69.18 to xxx.xx.72.33

      [12/Oct/2006:13:10:20-0700] conn=54 op=-1 msgId=-1 — closing — B1

      [12/Oct/2006:13:10:20-0700] conn=54 op=-1 msgId=-1 — closed.

   3. Execute the following LDAP search multiple times against the Directory Server load balancer:

      # cd /var/opt/mps/serverroot/shared/bin/ # ./ldapsearch -h LoadBalancer-1.example.com -p 389 -b "o=example.com" -D "cn=directory manager" -w d1rm4n4ger "(objectclass=*)"

      The ldapsearch operation should return entries. Make sure the LDAP search operations display in the same Directory Server access log.

   4. Stop Directory Server 1, and again perform the following LDAP search against the Directory Server load balancer:

      # cd /var/opt/mps/serverroot/slapd-am-config # ./stop # cd /var/opt/mps/serverroot/shared/bin/ # ./ldapsearch -h LoadBalancer-1.example.com -p 389 -b "o=example.com" -D "cn=directory manager" -w d1rm4n4ger "(objectclass=*)"

      The ldapsearch operation should return entries. Verify that the Directory Server access entries display in only one Directory Server access log.

      You may encounter the following error message:

      # ./ldapsearch —h LoadBalancer-1.example.com —p 1389 —b “o=example.com“ 
      —D “cn=Directory Manager” —w d1rm4n4ger

      ldap_simple_bind: Cant' connect to the LDAP 
      server — Connection refused

      The load balancer may not fully detect that Directory Server 1 is stopped. Or you may have started the search too soon based on the polling interval setting. For example, if the polling interval is set to 10 seconds, you can wait ten seconds to start the search again. Or you can reset the timeout properties to a lower value.

      1. Click the Monitors tab, and click the ldap-tcp monitor name.

      2. In the Interval field, set the value to 5.

         This tells the load balancer to poll the server every 5 seconds.

      3. In the Timeout field, set the value to 16.

         The default is 16 seconds. You can change this number to any value. In this deployment example, the BigIP documentation recommends the value should be at least three times the interval number of seconds plus one second.

      4. Click Apply.

      Repeat the LDAP search.

   5. Restart the stopped Directory Server 1, and then stop Directory Server 2.

      Confirm that the requests are forwarded to the running Directory Server 2.

   6. Perform the following LDAP search against the Directory Server load balancer.

      # cd /var/opt/mps/serverroot/shared/bin/ # ./ldapsearch -h LoadBalancer-1.example.com -p 389 -b "o=example.com" -D "cn=Directory Manager" -w d1rm4n4ger "(objectclass=*)"

      The ldapsearch operation should return entries. Make sure the directory access entries display in only the one Directory Server access log.