Services

The Qlik Sense services are the cornerstones of the Qlik Sense site architecture. The services can be deployed in different ways to suit different deployment purposes. For information on different deployments, see Deployment.

The Qlik Sense services are:

• The Qlik Sense Repository Service (QRS) manages persistence and synchronization of Qlik Sense apps, licensing, security, and service configuration data. The QRS attaches to a repository database and is needed by all other Qlik Sense services to run and serve Qlik Sense apps. The QRS also manages the synchronization used within multi-node Qlik Sense sites. In addition, the QRS stores the Qlik Sense app structures and the paths to the binary files (that is, the app data stored in the local file system).

• In a default Qlik Sense installation, a Qlik Sense Repository Database (QRD) service is created specifically for use by the Qlik Sense Repository Service (QRS). The QRS connects to the QRD to read and write data in the repository database. A PostgreSQL database is used by default.

• The Qlik Sense Proxy Service (QPS) manages the Qlik Sense site authentication, session handling, and load balancing.

• The Qlik Sense Scheduler Service (QSS) manages the scheduled reloads of Qlik Sense apps as well as other types of reload triggering (for example, task chaining) based on other task events.

• The Qlik Sense Engine Service (QES) is the application service, which handles all application calculations and logic.

The Qlik Sense services have the following dependencies:

• Repository database: The QRS connects to the repository database to store and retrieve data necessary for the Qlik Sense services on the node on which the QRS is running. In a default Qlik Sense installation, a Qlik Sense Repository Database (QRD) service is created specifically for use by the Qlik Sense Repository Service (QRS). The QRS connects to the QRD to read and write data in the repository database. A PostgreSQL database is used by default.
• File system: The file system contains the binary files for the Qlik Sense apps.
• Directory service: The QRS and QPS communicate with a configured directory service (for example, Microsoft Active Directory) using, for example, LDAP or ODBC.
• Start and restart of services: In a default Qlik Sense installation, the Qlik Sense Repository Service (QRS) depends on the Qlik Sense Repository Database (QRD) to be running. This means that the QRD must be the first Qlik Sense service that starts and that it should only be stopped when restoring a central node as described in Restoring a Qlik Sense site. The rest of the Qlik Sense services can be started in any order.