Normally, you should just install the Qlik Sense server, making sure that it is set as a central node during the installation. Then, you will get a single node installation. However, sooner or later you need to ask yourself a question about clustering, "How many servers do you want in your cluster?" This book is not a comprehensive guide to clustering issues; it will only point out the basics and the questions you need to ask.

In a standard installation, all seven services run on the same computer, and this works fine as long as the load on the server doesn't become too heavy. However, as soon as your installation starts to grow, you may need more computers to handle the load. If so, you can set up a cluster so that you have additional computers running only some of the services and still manage the entire cluster as if it was only one computer.

By far, the most common case is that Qlik Sense engine (the QIX engine) has a very large load, either due to many users or because some applications are large. Then, it might be a good idea to add one or several computers and use a separate Qlik Sense engine on each computer.

Another case is that you have several physical locations and want one node in each location, with the same content on each node. This way, the users always use the local node.

One of the computers must be set as the central node, that is, as the master. Here, you enter your license key and manage the entire cluster. Data will be synchronized from this node to other nodes.

It is possible to use the same entry point—the Qlik Sense proxy—for the entire cluster so that users don't notice that there are, in fact, several computers.

On the central node, it is recommended that you have a dedicated QPS and QIX that are used specifically for the QMC and not for the hub.

In addition, the central node must have the QSS installed even if other nodes with schedulers are added. This is because the scheduler on the central node is considered to be the master scheduler, which coordinates all scheduler activities within the site.

Hence, when defining your deployment strategy, you should try to answer some questions:

The answers will help you decide whether you need a cluster of Qlik Sense servers. If you don't know, or if it is your first server in a cluster, you should just install the Qlik Sense server making sure that it is set as the central node during the installation.

The first thing you need to do after installing Qlik Sense is to enter the license key and make sure that you get a valid License Enabling File (LEF) from the Qlik license activation server. However, this is not enough to get going. You also need to assign a license to yourself. Alternatively, to express this in the correct terminology, you need to allocate a token as a user access pass for yourself.

This is done by navigating to License and tokens | User access. Here, you can click on the Allocate button, select a user, and click on Allocate. This means you have given this user unlimited access to the Qlik Sense server. Unlimited means unlimited from a license perspective—you may still define restrictions on this user from a security perspective.

User access has been granted to one of the authors

The reason for this procedure is Qlik Sense's flexible licensing model. In the QlikView license model, you bought Named CALs or some other license from Qlik, and that was then the license you had. To convert from one type of CAL to another was not possible, unless you contacted Qlik.

In the Qlik Sense model, you have a greater degree of freedom. Here, you decide how you want to allocate the licenses you bought. Some are allocated to the equivalent of a Named CAL, while some are allocated to another license type. As a consequence, you don't buy licenses. Instead you buy tokens, which is a kind of currency that you can convert into licenses at a later stage. In the initial configuration, no tokens are assigned to be used and hence, the need to allocate a token to yourself.

Another consequence is that the terminology has changed. A Named CAL is no longer called Named CAL. Instead, it is called a user access pass. So in the preceding case, you have effectively given yourself a Named CAL.

The Qlik Sense user access pass—and the QlikView Named CALs for that matter—is a general unlimited license that should be given to frequent users, that is, users that analyze data regularly, many times every month or perhaps even daily.

In Qlik Sense, there is a second license type that is designed to cover the needs of infrequent users. It is similar to the Usage CAL that exists in QlikView. It is called login access pass. A login access pass is equivalent to one login per month, that is, the login counter is refreshed so that a new login is possible every 28th day.

You can create login access passes in batches of 10, and 10 login access passes cost 1 token. These 10 logins can be used anyway you want. They can, for example, be used by 10 different people that log in once per month or by one single user who logs in 10 times every month.

Login access passes can be created in pools for different groups of people

Typically, you would use several tokens to create a pool of logins that can be dedicated for a group of people within your domain. You can create access rules both for user access passes and login access passes, and you should do this for your own benefit. This means that you can, for instance, say that anyone in the finance department will get a user access pass when logging on, whereas the users of another department will share the login access passes of a specific pool.

Hence, when you create the user and login accesses you want, you can get an overview of the License usage summary page, where you can clearly see the number of used tokens and how many you have left to allocate.

You can clearly see how many tokens you allocated to licenses, and how these are distributed over the two access types in the following screenshot:

The License usage summary in QMC