You can configure how many QlikView Engines can be launched simultaneously, giving you control over the load of the server. However, there are two settings available for this:
Max Number of Simultaneous QlikView Engines for Distribution and Max Number of Simultaneous QlikView Engines for Administration.
What's the difference?
Max Number of Simultaneous QlikView Engines for Distribution
This governs how many engines can be used for reloads and distributions.
To set the number of QVBs that the QDS can send tasks to simultaneously, enter the desired number in this text box.
When the QDS detects that a task is to run (either manually or triggered), the QDS adds the task at the end of a queue that is based on the “first come, first served” principle. The QDS then goes through the queue and starts up the needed number of QVBs. If there are more tasks in the queue than QVB engines allowed by this setting, the QDS waits until a currently running QVB finishes and then starts up a new QVB to handle the outstanding tasks in the queue. The default value is 4.
Note that in a QDS Cluster, the settings will be applied pernode and not for the whole cluster.
Max Number of Simultaneous QlikView Engines for Administration
This setting refers to the number of available QVB engines for QlikView Publisher task creation or management when it is necessary to open the document - such as when configuring a reduction and the Open Document (Fig 2) button needs to be clicked. The default value is 20 and further configuration of this setting isn't typically necessary.