BES Relays

BES Relays allow an N-tier hierarchy to be created for the transmission of information from the BES Clients to the BES Server in the BigFix Enterprise.

Below are some frequently asked questions about BES Relays

What do BES Relays do?

BES Relays will "relay" information to and from the BES Client and another BES Relay or the BES Server.
BES Relays allow BES Clients to gather the latest information about new Fixlet messages, new actions, or new downloads.
BES Relays allow the BES Clients to pass status messages to the BES Server including action results, retrieved properties, and relevant Fixlet messages.
BES Relays allow BES Clients to register their last known IP address so they can be "pinged" later if there is new information to gather.
BES Relays allow BES Clients to download patches and other files.

Do I need to find/buy a separate dedicated computer to be a BES Relay?

No! BES Relays are specially designed to work on shared systems.
Any BES Client (on a supported BES Relay OS) can be a BES Relay.
Most customers will deploy BES fully without purchasing a single BES Relay (even the largest deployments with over 3000 BES Relays).
It is very common to deploy the BES Relay on server computers that already exist in the enterprise infrastructure. AV distribution servers, file servers, print servers, Active Directory servers, and more are all commonly used as BES Relays. Server computers make a good choice because servers tend to exist in the same places you want to place a BES Relay and they are rarely turned off; however, a server class computer is not a requirement of a BES Relay.
The BES Relay uses minimal computer resources and is idle most of the time and it is designed to have minimal impact on a computer so there are no conflicts with other applications/services running on the same computer.
BES Relays do not need server-class fault-tolerant hardware because the nature of the BES architecture makes the system fault-tolerant (because BES Clients will automatically fail-over to other near-by BES Relays in the event of a problem).
BES Relays can also be deployed on standard desktop computers with no problems. Examples from current customers include BES Relays on secretarys' computers, kiosk computers in retail stores, IT administrators' computers, and deprecated old desktop hardware that would have been thrown away but instead were used as BES Relays.
BES Relays require no additional 3rd party software (e.g., SQL Server, IIS, and other applications are not required for the BES Relay).

Why use BES Relays?

Bandwidth Savings - Often the BES Clients are not in the same geographic location as the BES Server, and often the different locations are connected by thin network pipes. By downloading from a BES Relay instead of the main BES Server, the information about the action and -- more importantly -- any files associated with the actions only need to be transferred across the thin pipe one time to the BES Relay instead of one time per BES Client. The BES Relay then distributes the information over the LAN to the BES Clients. The result is a substantial bandwidth savings. Without BES Relays, it would often be impossible to administer remote computers because of the bandwidth limitations.
BES Server Scaling - The BES Server has a database and a webserver and is the central communication piece of the whole system. A single computer can only accept so many inbound connections from BES Clients, BES Consoles, etc. Without using BES Relays, even a very powerful computer could easily be overwhelmed by only a few thousand BES Clients. By using BES Relays, you effectively distribute the load from the BES Server to the BES Relays allowing for the BES Server to scale to handle much more BES Clients, use less expensive hardware, and be more efficient.

How do BES Relays work?

BES Relays are simply BES Clients that are running two extra services (BESGather and BESRelay).
BES Relays act as a mini BigFix-specific webserver.
BES Clients connect using standard HTTP on the specified port number (default 52311).
BES Clients will request downloads, the latest Fixlet sites, and the latest action sites from the BES Relay.
If the BES Relay does not have the latest information, it gets the data from another BES Relay or from the BES Server.
BES Clients will send action results and retrieved property reports to the BES Relay, which will bundle and compress them and send them to another BES Relay or to the BES Server (the bundling and compression also saves network bandwidth).
BES Relays will cache downloaded files so that it will not have to re-download the files if they are needed later. BES Relays (default cache size is 1 GB, but is configurable) use a least-recently-used (LRU) cache replacement scheme for when the cache fills up.

How do you administer BES Relays?

Installing BES Relays is done by using an "Install BES Relay" task in the BES Console to designate a BES Client as a relay.
To uninstall the BES Relay, you simply run the "Uninstall BES Relay" task in the BES Console.
BES Clients can be told which BES Relay to point to by using the BES Console to set a BES Client (or groups of BES Clients based on properties like subnet, location, etc.) to use a primary and secondary relay.
BES Clients can also be set to automatically find their closest BES Relays based upon network hops.
BES Relays can be manually set to create a hierarchy or the BES Relays can establish a hierarchy automatically.

How does the BES Client/BES Relay Auto Selection work?

BES Clients will choose their closest BES Relay by periodically "pinging" each BES Relay to determine which relay is the closest based upon the number of network hops. The default BES Relay selection period is 6 hours and is configurable.
Each BES Client will make a list of their closest BES Relays. If they cannot reach their closest BES Relay because it is off or down, they will try the second closest, and so on.
If a BES Client cannot find any BES Relays or they are all down, the BES Client will connect directly with the main BES Server.
If more than one BES Relays are the same distance away from a BES Client, the BES Client will randomly choose amongst them.

What are the system requirements to be a BES Relay?

BES Relays must be Windows 2000, Windows XP, Windows NT SP6a, or Windows 2003 Server.
Internet Explorer 4.01 or higher must be installed.
Minimum CPU: Pentium 2, 400 Mhz.
Minimum RAM: 128 MB.
Minimum Free HD Space: 2 GB.
BES Relays should be computers that are likely to be powered on all the time.
BES Relays can be desktop computers that are generally in use by a user, but this configuration is not recommended because the BES Relay will add addition load to the system which might bother the user.
File servers, print servers, domain controllers, SMS servers, application servers, etc. are all very good candidates for BES Relays because they are generally already deployed in the appropriate locations, they are server-class computers, and they can generally easily handle the minimal additional load from the BES Relays.
It is recommended that you have at least one BES Relay per 500-1000 BES Clients (you normally deploy BES Relays on shared computers that already exist in your current infrastructure). The BES Relay is accepting many incoming connections and often distributing large files so even a powerful computer will get overwhelmed quickly by more than a few thousand BES Clients (because of bandwidth limitations). If there are more than a thousand computers in a particular location, simply choose another BES Client to become a BES Relay and the BES Clients will distribute themselves equally amongst the different BES Relays (if auto-selection is enabled).
If you have several levels of BES Relays in a hierarchy, you will need more powerful computers towards the top of the hierarchy than towards the bottom. The exact specifications of the BES Relay computers depends heavily on the specifics of each network. Contact your support technician for information for your particular deployment.

Here are some examples of computers that are top-level BES Relays and how many computers they can support (sum of all of the computers reporting to them plus all computers reporting to BES Relays lower in the hierarchy):

Top Level BES Relay Requirements * (These numbers have been revised to reflect BES 5.1 enhancements)

System Specs	Supported BES Clients (for child relays)
Dual 2.8 Ghz P4, 2 GB RAM	100,000
Dual 2.0 Ghz P4, 2 GB RAM	70,000
Dual 1.8 Ghz P4, 1 GB RAM	30,000
Dual 1.4 Ghz P4, 512 MB RAM	20,000
2.4 Ghz P4, 512 MB RAM	15,000
1.3 Ghz PIII, 256 MB RAM	10,000

Note: These are just examples for reference, contact your BigFix support technician for more information on requirements for your network.

Do you have a "best practices" list for maintaining a healthy BES Relay deployment?

Yes. Please see the BES Relay Health page for more information.