The simplest configurations consist of single standalone boxes that have a feed
handler and an application. In reality, very few production systems are
configured in this way, because of the customer's need for resilience. In the real world, Dataworks Enterprise boxes are duplicated at each layer in
the network. The Dataworks Enterprise cache has built-in support for "hot
standby" sources. Note, that Dataworks Enterprise resilience is
implemented at the level of logical sources as well as at the connection level.
If a source fails, irrespective of the cause, The Dataworks Enterprise cache
will attempt to mount an alternative source supplied by another route. The diagram above is the simplest configuration of Dataworks Enterprise Systems
and, currently, the most common. Typically, the remote client boxes are running
IIS servers and the remote server are running the feed handlers used by the Web
Site. The IIS are accessed by some distribution system such as an ArrowPoint. If one of the Remote Server boxes fails (or any source or other component on
that box), Dataworks Enterprise Cache in the Remote Client boxes will fail over
automatically to the other Remote Server box. Dataworks Enterprise cache does
not support "fail-back", so if the Remote Server box recovers, it
will become the standby. Note also there is no load balancing involved. If you are looking for a solution that includes load-balancing and automatic
recovery, then the module to look at is Hydra. Hydra load balances symmetric
Dataworks Enterprise sources and creates a new composite source. Suppose that
the Remote Client boxes in the above diagram also had a Hydra installed. This
system could be configured so that the Hydra ingests data from the Remote
Clients and make a composite load-balanced source for feeding to the IIS
processes. However, there are limitations. You need to have one Hydra for each
composite source. Also, Hydra only implements load-balancing on a "fair
share" basis. There is no notion of "cost analysis" or similar. At the next level, Dataworks Enterprise networks can become quite complex,
simply through using larger numbers of Remote Clients and Servers. The diagram above is a simplified version of part of the TFP Hub layout. Systems
can become very large and very complex, especially in terms of configurations.
The long term plan is to build and maintain a central TFP hub network to
support many clients. This will reduce the number of configurations and
construct a more stable network. Freeway can also be used to reduce the number of configurations by virtue of the
fact that it is a more self-configuring network architecture. The above
illustrates the combination of feed handlers (at the top), the Freeway network
and tail circuits built on remote client/servers and publishing client/servers. This layout extends the previous one by showing a similar layout using a thrid
party distribution system.Some Sample Network Layouts
This document is meant to illustrate some basic possible
network layouts for Dataworks Enterprise Installations. These layouts do not
necessarily exist, but they could. It is hoped that these diagrams will clarify
the intended use of various Dataworks Enterprise Components.
