Assigning engines to improve app performance
When you open an application, Qlik Cloud automatically selects an engine based on app size, reload memory usage, and available system resources. You can manually assign a larger engine to gain more control or improve performance. Manual assignments use Large app capacity.
Engine types and sizes
Qlik Cloud provides two types of engines: shared and dedicated.
Shared engines
Shared engines can run multiple apps concurrently and the default for smaller or less complex applications. They cannot be assigned manually and do not require Large app capacity.
Example specification:
-
60 GB RAM
-
Up to 14 CPU cores
Dedicated engines
Dedicated engines run a single app at a time and suited for larger or compute-intensive applications. They require Large app capacity and can be manually assigned.
Example specifications:
| Engine type | Memory | Up to cores* |
|---|---|---|
| Large-40 | 40 GB | 10 cores |
| Large-60 | 60 GB | 14 cores |
| Large-80 | 80 GB |
20 cores |
| Large-120 | 120 GB |
30 cores |
| Large-160 | 160 GB |
40 cores |
| Large-200 | 200 GB |
50 cores |
* “Up to” means resources are provisioned as needed. Not all CPU cores are used simultaneously for every calculation.
When to manually assign a larger engine
You may want to override the default engine placement when:
-
Your app has heavy visualizations or complex calculations that require more CPU.
-
Your app size or complexity exceeds the default engine allocation.
-
You want to test and validate performance gains using the built-in evaluation tool.
Manual assignments use Large app capacity, so always balance performance benefits against capacity usage.
Manually assigning engines to apps
You can manually assigna specific engine size to an app using the placement API. Manual overrides are available through API calls only, and require Tenant Admin or Analytics Admin permissions.
With the placement API, you can:
-
Assign an engine size to an app
-
Check which engine size is currently assigned
-
Remove an engine size override
For instructions and API details, see Qlik Developer: Pin applications to engine sizes.
Comparing app performance across engine sizes
The app performance evaluation tool in Qlik Cloud helps developers assess app performance during user interaction. It measures how efficiently app objects—such as charts, sheets, and KPIs—are calculated and rendered when the app is opened.
This tool is especially useful if you assign a larger engine to an application and want to verify whether the change improves performance.
What you can do with the evaluation tool
-
Measure how long it takes for specific charts, sheets, or objects to calculate.
-
Compare app performance across engine sizes to see whether assigning a larger engine improves speed and responsiveness.
Running a performance evaluation
You can run an application performance evaluation in several ways:
-
Directly from the activity center
-
As part of a Qlik Automate workflow
-
Via the Qlik Cloud APIs
This makes the tool accessible to developers working interactively as well as to those automating app testing.
For more information, see App performance evaluation.
Capacity consumption considerations
Manual engine assignments affect how much Large app capacity your app uses. The following rules apply:
-
Capacity used = engine size ÷ 4
-
Example: Assigning a 3 GB app to an 80 GB engine consumes 20 GB of Large app capacity at runtime.
-
-
Qlik does not reduce usage if the app doesn’t fully use the assigned engine.
-
If the app grows and is later automatically assigned to a larger engine, Qlik updates the capacity usage accordingly.
For more information, see Large app support.