In this example, we will show you how to build your failover cluster system. We will setup Ozeki NG SMS Gateway on two computers, and create the system that will move the SMS service from one computer to another. Please note that you can configure any windows service, not just Ozeki NG SMS Gateway in a similar way as in this example.
In a failover cluster setup only one of the Ozeki NG SMS Gateway nodes operate at a time.
We distinguish the master node and the slave node. The master node serves ALL the clients at any given time, the slave node serves NONE.
The master node is connected to ALL the SMS service providers, the slave node is NOT connected to any provider.
During normal operation the master node is 'On-line' the slave node is 'Off-line' (Figure 1).
Figure 1 - Normal operation
In case the master node goes down because of a hardware failure, the slave node is automatically activated.
It picks up the configuration and the message queues from the shared disk, and continues to provide the service where the master node left off (Figure 2).
Please note that this configuration requires persistent message queues.
Figure 2 - After failover
Figure 3 shows the network configuration of our example setup. The cluster IP address must be different from any other IP address used on the network.
Figure 3 - Example network configuration
Step 1 - Setup the Cluster IP address
On the home page, click on 'Edit' (Figure 4).
Figure 4 - Click on 'Edit' button
In the Cluster IP address menu, (Figure 5) you need to add the cluster's IP address. It must differ from any used IP address on the network. The netmask, gateway, and DNS fields are filled automatically. If you are finished, click 'Ok'.
Figure 5 - Provide the IP address of the Cluster
Now it's time to set up the Slave node(s) on the cluster. As a remark, the Master node is already configured automatically.
Step 2 - Navigate to the 'Computers' page.
On the home page select 'Computers' on the right hand side panel (Figure 6).
Figure 6 - Navigate to the 'Computers' page
Step 3 - Configure the Slave node(s)
Click on the 'Add computer' button in order to see the 'Computer' window to the right.
In this pop-up window you need to add the details of the Slave node.
Host - The Slave computer's IP address.
Port - OZEKI Cluster's port number on the Slave computer
Role - In this case, the role is set to Slave.
Finally click the 'Ok' button to save the configuration. (Figure 7)
If you would like to add more slave nodes, just repeat Step 3. You can change the Master node configuration as well, if needed.
Figure 7 - Configure the Slave node
Let's add some services to our cluster!
Step 4 - Navigate to the 'Services' page
Select 'Services' from the right panel (Figure 8) to add a service to the Cluster.
Figure 8 - Navigate to the 'Services' page
Step 5 - Add Ozeki NG
On the left hand side list, select a service for example OZEKI NG. Then click the 'Add' button in the middle of the screen (Figure 9).
Figure 9 - Adding a service e.g. OZEKI NG
The service should now appear in the 'Selected Services' list (Figure 10).
Figure 10 - OZEKI NG in the 'Selected services' list
If you would like to add more services, just repeat Step 5 with another service.
Step 6 - Set the boot delay (Optional)
You can set the boot delay according to the boot time of the slowest booting node. Therefore if the slowest node is not turned on by the time Cluster has already started running then it will result in unavailability of that node. We have already set up a default boot delay time which is 120 sec. You can set this function easily by clicking on the 'Configuration' menu and choose 'Boot delay' submenu. A diagram is also shown on this page which represents you the situation. (Figure 11).
Figure 11 - Setting boot delay
Step 7 - Synchronize the configuration settings of the nodes (Optional)
This feature can be useful in cases when one of the nodes stops working or any modifications happen. You can add the settings of the shutdown or modified node to the other ones therefore the configs will be the same on every computer. If you click on the 'Configuration' menu you will find 'Service configs' submenu where you can setup this solution. Then click the 'Add' button and a box will appear in which you can give the access path of the directory including the settings of the service you would like to synchronize. (Figure 12) For more information please read the: File synchronization page
Figure 12 - File synchronization
Step 8 - Start the cluster
If you have followed this guide thoroughly, you will see a similar result as shown in the pictures below.
Finally, click the 'Start' button to start the cluster (Figure 13).
Figure 13 - Starting the cluster
If everything went fine, you should see all of the selected services running (Figure 14).
Figure 14 - Cluster is running
Once we are done we can set up different services like the real time folder transfer. Read our detailed guide here: Setting up file transfer from folders with the Ozeki Cluster.