Using relays

Relays can significantly improve the performance of your installation. Relays lighten both upstream and downstream burdens on the server. Rather than communicating directly with a server, clients can instead be instructed to communicate with designated relays, considerably reducing both server load and client and server network traffic. Relays work by:

• Relieving downstream traffic. The IBM Endpoint Manager server has many tasks, one of the most cumbersome being the distribution of files, such as patches or software packages, and Fixlet messages to the Clients. Relays can be set up to ease this burden, so that the Server does not need to distribute the same file to every Client. Instead, the file is sent once to the Relay, which in turn distributes it to the Clients. In this model, the Client connects directly to the Relay and does not need to connect to the Server.
• Reducing upstream traffic. In the upstream direction, relays can compress and package data (including Fixlet relevance, action status, and retrieved properties) from the clients for even greater efficiency.
• Reducing congestion on low-bandwidth connections. If you have a server communicating with computers in a remote office over a slow connection, designate one of those computers as a relay. Then, instead of sending patches over the slow connection to every client independently, Server sends only a single copy to the relay (if it needs it). That relay, in turn, distributes the file to the other computers in the remote office over its own fast LAN. This effectively removes the slow connection bottleneck for remote groups in your network.
• Reducing the load on the server. The IBM Endpoint Manager server has many tasks including handling connections from clients and relays. At any given instant, the server is limited in how many connections it can effectively service. Relays, however, can buffer multiple clients and upload the compressed results to the server. Relays also distribute downloads to individual clients, further reducing the workload of the server and allowing the program to operate faster and more efficiently.

Relays are an absolute requirement for any network with slow links or more than a few thousand clients. Even with only a few hundred clients, relays are recommended: they make downloads faster by distributing the load to several computers rather than being constricted by the physical bandwidth of the server.

IBM Endpoint Manager is quite powerful; it is easy to deploy an action causing hundreds of thousands of clients to download very large files. Windows XP SP2 alone is more than 200MB and it is not uncommon to distribute software packages that are gigabytes in size. Without relays, even network pipes as fast as T1 (or faster) lines can be overwhelmed by many clients requesting large, simultaneous file downloads.

Establishing the appropriate relay structure is one of the most important aspects of deploying IBM Endpoint Manager to a large network. When relays are fully deployed, an action with a large download can be quickly and easily sent out to tens of thousands of computers with minimal WAN usage.

In an effort to ease deployment burdens and reduce the total cost of ownership, the relays run on shared servers such as file and print servers, domain controllers, SMS servers, AV distribution servers, and so on. As a consequence, a typical installation has less than 1% of its relays running on dedicated computers.

Generally, a relay uses minimal resources and does not have a noticeable impact on the performance of the computer running it. The IBM Endpoint Manager Clients can be set to automatically find their closest relay. These features allows for significant savings in both hardware and administrative overhead.