Setting up farm instances with a shared configuration

You maintain only one installation for all members of a farm in a shared configuration. Farm maintenance is easier because it is deployed to only one system. The single installation is shared by multiple servers, which has significant benefits.

About this task

The disadvantage is that there is no ability to apply specific changes on a per-server basis. If you did, the change would be visible through the shared file system and shared database to all members. Most maintenance requires downtime of the farm. Implement a "two lines of production" system to avoid downtime and eliminate the shared installation as a singe point of failure. With this setup, there is a shadow installation of the Farm in an active and passive mode of operation.

The server that is used to maintain the farm installation is referred to as the Farm Master.

There are certain HCL Digital Experience functions that are designed to run on a single node in a cluster; for example: seedlist generation. When you configure a portal farm with a shared file system, all of the farm client members read their configuration information from a single, master server. The enable-farm-mode task prepares the profile to support the shared file system operation. The enable-farm-mode task also disables the functions designed to run on a single node; for example: seedlist generation and subscriptions. Disabling these functions keeps all members from running the same services at the same time. If you plan to use search, configure a dedicated support server to run these tasks. The support server is unique in some of its configurations. However, it must share many of the same configuration as the other farm members, such as database connections and security configurations.

There are multiple ways to create the support server, including taking advantage of multiple profile support or separate installations. When the support server is on its own server, copy the master server profile to the support server. The directory paths must match on both servers (master and support). You can rely on the base HCL Portal and IBM® WebSphere® Application Server binary installation directories shared on the master file system and reference the local file system for the profile. See the Messaging Bus image:

A shared portal farm configuration includes four farm profiles, the networked storage, a support server, and the shared databases.

The following annotations apply to the image labels:
1. Messaging engine
The messaging engine is optional. Run the create-wcm-jms-resources task. Go to Setting up farm instances as unique installations for instructions. If not complete, run the create-wcm-jms-resources task on the farm master server to read messages from this server.
2. Subscriber
This server is the syndication subscriber. No action is required on this profile. Read Working with syndicators and subscribers.
3. Search engine
Follow the instructions to set up a remote search server in a cluster. Read Configuring search in a cluster.
4. Shared portal
Shared portal with the filesystem replication or other sharing techniques. Read Configuring a cloned or shared file system.
5. Shared application server
Shared application server with filesystem replication or other sharing techniques. Read Configuring a cloned or shared file system.
6. Unique profile
Unique profile with filesystem replication or multiple profiles support. This profile is configured differently than the farm master. It is isolated from the farm workers to support operations in this list.
7. JCR database domain
The JCR database domain is inherited from the initial farm profile configuration. There is no need to change the database domains.
8. Customization database domain
The Customization database domain is inherited from the initial farm profile configuration. There is no need to change the database domains.
9. Communication database domain
The Communication database domain is inherited from the initial farm profile configuration. There is no need to change the database domains.
10. Release database domain
The Release database domain is inherited from the initial farm profile configuration. There is no need to change the database domains.

Complete the following tasks to set up your farm instance with a shared configuration: