Linux Enterprise Cluster: Build a Highly Available Cluster with Commodity Hardware and Free Software
The cluster node manager, the NAS device, the Thin Client server, the SQL server, and the high-availability serial solution we've built all sit outside the cluster, as shown in Figure 20-7.
The Cluster Environment
As you can see, both PC clients and LTSP Thin Clients can access the cluster services, using a web browser, for example. (For telnet access to Linux from a Windows PC, see the free telnet client called PuTTY.) Notice in this figure that all of the servers used to support the applications that run on the cluster are built with no single point of failure.
| Note | Figure 20-7 does not show the underlying network infrastructure that the cluster is built on top of. If your budget permits, you should also build this network infrastructure with no single point of failure and split each server and half of the cluster nodes on to separate network hardware components (separate network switches). Also not shown in Figure 20-7 is the disaster recovery data center that contains a mirror copy of the hardware, software, and critical data. |