A load-balanced configuration requires that the first application server and database server be installed using the two server configuration model. After that, the Installer can be run again on each additional application server to install only those components. Each additional Web/application server must also meet the required prerequisites.
Make sure that the hardware, software, and network are prepared before beginning to configure and install Blackboard Learn in a load-balanced environment.
Network File Share and Common Internet File System
Clients on UNIX platforms should use a network file share (NFS).
Clients on Windows platforms should use a common Internet file system (CIFS).
Hardware Sizing Information for Windows Dell Environments and Hardware Sizing Information for UNIX Sun Environments detail several different hardware configurations based on performance, cost, and redundancy. Read this document to make sure that the planned hardware configuration meets the needs of the institution.
SPARC hardware is required for to install and run Blackboard Learn under Solaris operating systems.
For the exact versions of the operating systems, databases, and Java SE Developers Kit (JDK™) that are supported, see "Supported Technologies" in the Release Notes for the release that you are installing. It is critical that the software used to host Blackboard Learn meets requirements.
The supported version of the JDK can be downloaded at http://java.sun.com/javase/downloads/index.jsp.
Download and install the JDK on each application server.
Make sure that the server or servers are dedicated to Blackboard Learn. Make sure that the server is not using valuable space and resources running unnecessary applications.
Required Libraries in a Red Hat Environment
- apr-1.2.7-11.el5_3.1 (or similar version)
- e2fsprogs-libs-1.39-23.el5 (or similar version)
- gdbm-1.8.0-26.2.1 (or similar version)
- glibc-2.5-42 (or similar version)
- libaio-0.3.106-3.2 (or similar version)
- libgcc-4.1.2-46.el5 (or similar version)
- libstdc++-4.1.2-46.el5 (or similar version)
Select one of the existing application servers to also act as the collaboration server. Optionally, configure a separate collaboration server. To learn more, see Set Up a Collaboration Server. The collaboration server may not be spread across multiple application servers because all users participating in a collaboration session must share the same resources. A single server must be configured to run the collaboration server. This server must handle collaboration sessions and performance will be unaffected by other requests. The application servers are configured to connect users to one server that handles all the collaboration sessions.
Do not connect the collaboration server to the load-balancer.
Dedicated File System Server
Set aside one server as a dedicated file system server. The content files must be centralized so that all files are available to users regardless of the application server handling the connection. The application servers are configured to find the content files in a directory on the file system server.
Institutions can use the load-balancing method of their choice as long as it adheres to a few basic principles:
- The load-balancing method must use cookie-based session affinity.
- If SSL is used, the same certificate must be shared by all the application servers. More information about SSL can be found in SSL Choice. Do not use the "SSL acceleration" or "SSL off-load" features of the load-balancer.
- The /etc/hosts file must have an entry for the virtual IP’s hostname that points to the localhost (127.0.0.1).
Create a UNIX User for Blackboard Learn
The Installer requires a user with permissions on the directory where Blackboard Learn will be installed. The UNIX user must be created prior to installation with the following parameters.
- The user name must be bbuser.
- bbuser must have a valid home directory. Blackboard recommends using /home/bbuser for Linux operating systems and /export/home/bbuser for Sun Solaris operating systems.
Synchronize Server Clocks
Check the date and time on the system and make sure it is accurate and that the time zone is set correctly. If installing on two servers check that the time on the application server and database server match. Remember that the servers may be in a different time zone than users. The server time zone should be the same as the time zone used by the majority of users, instead of the physical location of the server. Blackboard Learn uses the server date and time to control the availability of time-sensitive materials. It is important that users have a clear expectation of when materials will be available and when assignments are due.
Blackboard Learn requires ports to communicate. Following are the required ports and their default values. Make sure to configure server security and any firewalls to allow communication on the required ports. The port values must be the same for each application server.
- Web server port (default value: 80): This port handles communication between users and the server.
- Web server SSL port (default: 443): This port is the primary web application port when SSL is in use.
- SQL Server Listener port (default value: 1443): This port connects to a database in a Windows environment.
- Oracle TNS Listener port (default value: 1521) This port connects to a database in a UNIX environment
- Internal Tomcat communication port (default value: 8009)
- Collaboration server TCP/IP port (default value: 8010): This port handles TCP communication for the Collaboration server. By default, TCP communication connects users to the Collaboration server.
- Collaboration server HTTP port (default value: 8011): This port handles HTTP communication for the Collaboration server.
- Collaboration server SSL port (default: 8443): This port handles secure communication for the Collaboration server.
Any port higher than 1024 must be open between the application servers so that they can communicate through the peer services framework.
Do not use a firewall to redirect ports. The internal port configured on the server must match the external port on the external firewall.
Keep in mind the following when connecting Blackboard Learn to the network:
- Do not use underscores in the machine name for the server or servers. Some versions of Internet Explorer block cookies if the machine name includes an underscore.
- Set up the DNS server to resolve the hardware load-balancer. The hardware load-balancer will then direct traffic to the application servers. Set up a separate DNS entry for the Collaboration server.
- Check with a network engineer to make sure that the network can handle the anticipated load after Blackboard Learn is made available to users.
- An SMTP server must be available so that the Installer can connect to it.
- An SMTP server has to remain available when the application is running in order to deliver email notifications.