This is a pre-release of updated documentation which covers Qlik Sense and NAS devices. The documentation will be updated later in the year.
A Qlik Sense site will store data to both a repository database for system & app metadata and file share for the binary application data (such as data models and app content). In a single-node deployment, both of these are usually on the name machine as the Sense services. In a multi-node site a cluster is formed around a single repository database and file share. In many cases, it may be required to separate these out such as for resilience or performance.
Below are the requirements for each element of persistence in Qlik Sense.
For best performance, we recommend that you locate all your Qlik Sense servers in the same geographic location or data centre or that network latency between machines is below 4 milliseconds to avoid any performance degradation.
In a Qlik Sense site, a file share is used to the store the binary app data including the data models in the apps and the app content. It can be located on one of the nodes in the Sense site or located on a dedicated server for better resilience and performance. You create this folder before you install Qlik Sense.
The requirements for the share are as follows:
The Sense nodes in the cluster must have network latency of 4ms or better to the file share server, beyond this performance can degrade
The bandwidth to the file share must be appropriate for the amount of traffic in the site – the frequency and size of apps being saved after reloading and opened into memory drives this. 1 Gbit networking is suggested
The file share can run from:
A Windows Server OS (this option is most common) - this windows device may have storage allocated to it from a SAN, use local disks or virtual storage in the case of a virtual machine
A non-windows device such as a Linux server or Hardware NAS device that supports SMB 3.0 (see additional notes below)
The file storage must have a single read/write master, while the storage can be replicated to standby storage only one location can be used for all reads and all writes
Note: Qlik cannot verify support for all storage vendors and Qlik recommends that customer’s test their preferred infrastructure. In the event of an issue arising that is attributed to storage Qlik Support may request customers replicate the issue on a Windows hosted file share.
In a Qlik Sense site, a PostgreSQL repository database is used to storage all data for the Sense Repository service including system and meta data. It can be located on one of the nodes in the Sense site or located on a dedicated server for better resilience and performance. You create this folder before you install Qlik Sense.
You have two options for the repository database:
Install as a local database on a central node - This is an option in both single-node and multi-node sites and is covered in the Qlik Sense Installer
The Sense nodes in the cluster must have network latency of 4ms or better to the database share server, beyond this performance can degrade
If Qlik Sense uses a PostgreSQL database on a dedicated infrastructure then it can use PostgreSQL version 9.6. You can run the instance of PostgreSQL on platforms including Windows, Linux or cloud hosted services such as Amazon RDS. However, Qlik will only offer configuration support when PostgreSQL is running on Windows. If you use Linux or Amazon RDS, it is your own responsibility to install and configure a running instance of PostgreSQL for Qlik Sense to use.