Configure High Availability mode (optional)

To configure the IMSA servers to run in High Availability mode: configure an additional IMSA server or servers; set up a sprayer or load balancer; and, if you want, remove servers from an IMSA pool.

Configuring additional IMSA servers

Procedure

Open the group that holds all your IMSA server cluster-mates (servers in the cluster that have the IBM® mail add-on server installed).
1. Open the Domino® Directory and select Groups.
2. Select the group name you had previously selected when configuring your DB2® server.
3. Add the name of your additional server(s) to the Members field.
4. Click the Save & Close button.
Copy the DB2 jar file from the DB2 server to the added ISMA server(s)
1. On the DB2 server locate the file, db2jcc4.jar, in [db2_install_dir]\sqllib\java\
2. Copy db2jcc4.jar to the ISMA server in the directory [full_Domino_executable_path]\Traveler\lib
Set the enterprise server database administrator's user name and password
1. Open the Domino Administrator client and connect to a server you want to update.
2. Choose the Messaging > Mail tab, then Tools > Microsoft Outlook and select Set Database Password.
3. Enter the user name and password, then click OK.
4. Repeat substeps A through C for every additional server in the group.

Setting up a sprayer or load balancer

About this task

You will need to set up a sprayer to point to the highly available servers in the pool.

Note: IBM mail support for Microsoft Outlook only supports configurations where all servers behind a sprayer are database-complete, in regards to user mail files - i.e., each user must have a replica on each server the sprayer directs to. This requirement can be lifted if logic is added to your sprayer to detect which servers have mail files for a user, and only direct traffic to such servers.

To support a pool of IMSA servers, you will need to provide a single URL entry point for the clients. This can be accomplished by employing an IP sprayer or load balancer, allowing a client to connect to one URL and have the request routed to any of the IMSA servers in the pool.

IMSA has minimal requirements for an IP sprayer:

Provides a single URL entry point and supports the proxying of device requests to two or more IMSA servers
"Round-robin" load balancing. This will spread the load evenly across the Domino HTTP tasks. The IBM mail add-on provides its own load balancing based on server load characteristics, after it has received the requests from Domino HTTP.
Ability to detect when an IMSA server is no longer responding, to allow for failover.

Procedure

After configuring an IP sprayer, you must update the IBM mail add-on external URL to point devices to the URL of the sprayer; the external URL setting can be modified in the server document. The URL must be updated on each IMSA server in the high availability pool. Once the URL is modified, you must restart the IMSA server.

Open the Domino Administrator and select the Configuration tab. Select Server > Configurations.
Open a server and click the Edit Server Configuration button.
Select the NOTES.INI Settings tab, and click the Set/Modify Parameters button:
In the "Item" field, enter NTS_EXTERNAL_URL.

In the "Value" field, enter https://[sprayer address]/traveler,, where [sprayer address] is the address of the IP sprayer. As an example: https://outlookserver.ibm.com/traveler.
Click Add/Update, then click OK.
Click Save & Exit.

You are now ready to connect to your IBM mail via Outlook through the sprayer, and not through the individual servers.

Note: In addition to the IP sprayer required for High Availability, IBM recommends configuring a web proxy (i.e., F5 or Websphere Edge) for client-side SSL termination. If you need access from outside the firewall, IBM recommends using a Secure Access Gateway (i.e., IBM Mobile Connect).

Note: If you choose to use IBM Mobile Connect as a Secure Access Gateway, you will need to configure the Freebusy URL in your environment to point to a specific IMSA server. IBM Mobile Connect will not allow anonymous access for Freebusy lookups.

Removing a server from an IMSA pool

About this task

The IMSA servers in a High Availability pool are all configured to use the same enterprise database; this database contains a table used to track the servers that are participating in the pool. If you want to remove a server from the pool:

Procedure

Update the network configuration and sprayer/load balancer to no longer route requests to the removed server.
Choose one of the following uninstall methods to remove the IBM Mail server add-on from the backend server:
1. Uninstalling from the operating system menu, unless otherwise specified, will remove all files, as well as Notes®.INI settings. This will completely remove IMSA from the server.
2. Using the travelerUtil utility and issuing the db remove command will keep all files and Notes.INI settings, but physically remove the server from the enterprise database. This will keep IMSA on the server as a standalone system.
Run the tell traveler hadr delete [servername] command. This will remove the IMSA server as a member of the High Availability pool from the enterprise database table. You can run the tell traveler hadr show command to verify that you are no longer displaying the server you just removed.