SMQ Round Robin Clustering Example
Round Robin DNS provides a low cost alternative to traditional cloud services. We recommend reading the DZone article Cheaper Alternatives to IoT Cloud Services if you are new to Round Robin DNS.
We have selected a low cost Virtual Private Server (VPS) provider for our example, and we have the servers located in: Portland, Los Angeles, Phoenix, and Denver. The geographical dispersion provides strong redundancy. The yearly lease for each server is $11.99, thus the total cost for our example cluster is $47.96 per year.
We have four html frames below, and each html frame opens the IoT LED example on a separate server. The domain name simplemq.com translates to four IP addresses (four online servers) and you randomly get one of these IP addresses when navigating to simplemq.com. However, we have also configured the DNS such that you can navigate directly to a specific cluster node.
Notice that clicking a button in any frame window below is synchronized among all four frame windows. Not only does the SMQ protocol provide synchronization between multiple HTML5 clients, SMQ also automatically synchronizes between the servers in the cluster.
Before clicking any of the LED buttons below, make sure to select the same device in each window. You do this by clicking the same IP address in the left pane for each window below.