More than 95% of our customers use the LoadMaster in pairs. This is quite obvious, especially if it’s not only all about performance and scalability, but also about availability when the LoadMaster should not be a “Single Point of Failure”. This combination of two load balancers is usually referred to as HA-Setup (HA = High Availability).

Default settings

The default setting for this example is the system I have described in the previous “cookbook” article.

Warning:  If you own a HA-2 appliance or have received the VLM licence please leave them switched off for now.

First you need to make sure that an existing Default Gateway is entered.  This doesn’t need to be a router just a system the LoadMaster can access in the local network. In my case I am just using my Laptop’s IP, the same laptop the VLM is running on.

Please enter a working NTP server.

If your existing system is already HA-1 configured (for example a licensed hardware LoadBalancer or a HA-1 VLM license), please continue with the chapter Adding a HA-2 LoadMaster.

If you don’t have a HA-2 license already, I recommend applying for it now:
- start a second VLM LoadMaster as explained in the “Cookbook” article “Installing a Virtual LoadMaster”.

Now let’s go back to the already existing LoadMaster. First we check the interface settings.

Clicking “Home” shows the address of the LoadMaster.

Have a look at the grey bar. There is nothing to see yet next to the LoadMaster Vitals. We will come back to this later...

Changing the LoadMaster to HA-1

Now we want to change the existing system to HA-1. Please go to “HA Parameters” and switch from “Non HA Mode to “HA (First) Mode” (also called HA-1).

Now confirm the necessary reboot.

Subsequently confirm the browsers warning about the non-certified signature. Note the changes that happened. You should see the red/green boxes in the already mentioned grey bar and a reduced menu on the left-hand side.

Now it is getting serious, we are going to do the actual cluster settings.

Some preliminary thoughts first:

Until now we used the same IP for all access to the LoadMaster.
With a combination of two LoadMasters we need to differentiate:

1. There are activities relating to all Loadmasters, for example changes to the virtual service or alarm settings.
2. Activities relating only to one LoadMaster, for example reboots, changes to the IP address or software updates.

For the latter ones you can access the LoadMaster by its own IP. We have done just this right now and therefore can see on the menu on the left-hand side “Local Administration”. This allows us the activities described at b).

For a) we use the overall access via a shared IP, which affects both LoadMasters in the cluster. Therefore we need an additional “virtual” IP address. This is used for managing the whole HA-Cluster. Here we are talking about a “Shared IP” or a “Managed IP”.

Let’s summarise:

• “Physical” IP for the first LoadMaster (“HA-1”) – 192.168.69.251 in this example
• “Physical” IP for the second LoadMaster (“HA-2”) – 192.168.69.252 in this example
• “Shared” IP for the LoadMaster cluster - 192.168.69.250 in this example

Now we enter this into the eth0 configuration and confirm each value clicking the related button.

Then we reboot to activate this configuration. By now little has changed, except you can see the “shared” IP next to the “physical” IP.

From now on you can use the “Shared IP” to manage the cluster, as we have considered before. Access the cluster via https://192.168.69.250 (confirm the browser warning about the unofficial certificate). And voila – we have got back the familiar menu on the left-hand side.

You have now finished configuring the LoadMaster to HA. This setup will appear as a LoadMaster cluster with one knot switched off. All Virtual Services should work as usual.

Adding the “HA-2” LoadMaster

Next we need a second LoadMaster with HA-2 license.

• Owning the hardware you most likely will have the appropriate “HA-2” license installed already.
• Working with a VLM you should now start the second instance and enter the license according to the article about VLM-Setup.If you haven’t done so already, please order a license as described in the mentioned article. Doing so select “HA-2”.

After entering the HA-2 license in the new VLM – and forced password change – we will access the Loadmaster using the keyboard and VGA screen for a change.

Doing so we enter the standard informations:

The new VLM will now connect with its partner:

Tip: In a VMware environment it might happen that the initial step might not work immediately (“Failed to receive configuration...”) caused by timing problems. But there is a reliable workaround:

<N>o – no entry
<C>ancel – cancel quick setup
7 – Utilities
1 - Software Upgrade (confirm warning)
3 – Reset to factory defaults (confirm warning)

Careful: The pass word will NOT be reset for security reasons. Use the changed password to log in again. From here onwards things should work smoothly.

Finally we reboot the LoadMaster.

After the reboot the access via the shared IP should show two green squares:

And now the “HA-2” cluster is up and running – enjoy testing!

Before you go live there are a few fine-tuning arrangements to consider which are explained in the next “cookbook” article.
Important Note: To react robustly in every situation the LoadMasters needs two independent connections (for example via eth0 and eth1).
Multiple LoadMaster interfaces must NOT be in the same network (eth0 and eth1). Details can be found in the LoadMaster documentation.

Still having problems with the cluster configuration? Then the article about troubleshooting a HA-setup should help.

Also the KEMP-support will be happy to help.
As always we are looking forward to your feedback.

This manual is based on the LoadMaster Firmware Version 5.1-45.