Best Practices of Qlik Sense Multi-Node Setup, Load Balancing & Maintenance(Let's Discuss Here)

[rohitk1609]

Hello Everyone,

First of all, thanks for reading! I found it is amazing to connect myself to people around the world and communicate with my writings.

This page is indented to discuss best practices for  Multi-Node Setup & Load Balancing primarily, You may drop your use case or problem in comment, we will provide you best possible solution instantly.

Below content guide you to set up Multi-Node Qlik Setup & Load Balancing. It will help you to know Qlik technical terms, ask question more precious way which will help usor anyoe to provide solution more accurately.

Business intelligence is an agile process, gradually BI solution changes and updates. Enterprise grows so are data and end users.

When data grows and business logic gets complex, we need more resources to calculate the result and serve to users. Afterwards, Single Node (small) site performance decreases with time which could lay down the credibility and quality of BI solution.

Multi node site is  Qlik site(could have multiple Qlik servers ) where load is getting managed between more than one system and could have more than one  Fai-lover Candidate which takes charge in absence of central node automatically.

Note: we can have multiple fail-over candidates in one site, we call it passive central.

There are certain parameter which help you to take decision whether we should move to multi node site or remain on single node.

https://help.qlik.com/en-US/sense/June2018/Subsystems/PlanningQlikSenseDeployments/Content/Deploymen...

So below content is for such users who have made mind to upgrade their Qlik site to multi node.

Few naming conventions we will follow in below content:

1. Consumer node: which must has proxy service enable
2. Scheduler node: which has scheduler and engine services are enabled
3. Central: which is controlling whole Qlik site.
4. Failover Candidate(Passive central)
5. Resources: RAM and Cores(virtual cores)

Since June 2017 , installation setup has shared persistence way only where Apps and RepoDB data stay at persistence layer and both are shared with other nodes (rim or child).

Now why do we need to share Apps and Repository data with child or rim nodes?

Answer: to manage load in simple

Next Question: what exactly we share to balance the load practically?

Answer: Resources in Qlik site.

Next Question: what will be achieved if we share the resources?

Answer: Reduce the resource consumption while end users are accessing apps from one node i.e. central to consumer node (proxy service is must) and reduce the resource consumption and distribute it to scheduler node (scheduler and engine service is must) while any app reloads.

There could be many scenario how you would design your multi node site:

1. You want one central and one consumer and one scheduler node.
2. Two scheduler and two consumer and central
3. Central and scheduler node.

Ideally: Two scheduler and two consumer and central node comes in best practice for extra large enterprise.

You can read about single node, small, medium , large and extra large Qlik shared site in detail:

https://help.qlik.com/en-US/sense/February2019/Subsystems/PlanningQlikSenseDeployments/Content/Sense...

Multi node site would increase your Qlik Sense site availability, how?

We have a concept fail-over candidate, which is one of the scheduler node or such node which has all services and take charge automatically while Central node is down. We can manipulate the sensing time of failover candidate to central node in latest version.

Solutions which will guide you to deply multi node side

1. How to Install multi node site:

Installation of Multi Node site

Installing Qlik Sense in a multi node site - Qlik Sense

Qlik Sense September 2017 - Installing Qlik Sense in a multi-node site

1. How to configure multi-node site:

         Configure a multinode installatio

       2.  Load balancing:

      Adding load balancing

       Load balancing

       Configuring load balancing to isolate development nodes

          3. Fail-over candidate

Fail- candidate or we can call it passive central node which is ping in a set time(you can customize it below 10 minutes) to central or master node and when it doesn't get response it will take charge and become active central or master node.

Note: Where you install your postgresDB during installation that server has one extra service Qlik Repository Database which is running the postgresDB. So in case you don't have a dedicated persistence layer and installed Repo DB on central node(any server which has Qlik Sense too) then if your central node get down due to power failure or blue screen then fail-over node won't take charge. 

Primary condition of fail over concept needs QlikSenseRepositoryDatabase to be run all time. if QlikSenseRepositoryDatabase is down then whole site is down. 

One important application is attached to article which helps you to review your Qlik site. If you  have any concern over Qlik repository size, QLogs DB size or any component which is accessing excess size than expected, then download the app, import to your Qlik Sense, open it on HUB, there will be three connection which come along with application i.e. PostgreSQL_postgres, PostgreSQL_QLogs and PostgreSQL_QSR. Update password with your super user password of postgresDB which you entered during installation and save it. 

If your user name added as postfix after updatation of connections , go to QMC and make it as they were earlier.

Please do above activities by RDP not from end user side. Reload the app and share it with me so I can review it.

After utilizing above solutions, please post your queries in comment section what is your use case i.e. how many servers are available, how your user comes to site, network load balancer is available or not, reloads are executing on scheduler nodes etc.

In general, multi node or load balancing concept is vast and vary with client to client, so I do believe you may ask question much better when you understand the right terms of Qlik, went through above articles and requirements are clear.

Consider this resource as a open form where we all can post our queries on load balancing and multi node site.

There are few other documents which would help you in Qlik administration

1.Dynamic Sheet Exception With Stream and App Level Security

2.Sheet or App Object Level Security Qlik Sense

Reach to me if there is need of any clarification or need assistance with kumar.rohit1609@gmail.com

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Thanks,
Rohit Kumar

[rohitk1609]

drop an note at kumar.rohit1609@gmail.com. let me look into it

[mjperreault]

Hi @rohitk1609 ,

We are experiencing an interesting issue after changing our environment from one single node to a three node setup. 

The three nodes are 

1. Central / Scheduler Node which has all services

2. Consumption Nodes which have repository service, engine service and proxy service.

Each node has its own virtual proxy which connects to its own proxy service.

Users will only access the two consumption nodes, not the central node. Randomly users are getting a no access pass error which seems to be related to too many active sessions.  This will happen when users open and close there browser.  We are confused as to how users are getting too many sessions when they are only accessing to different virtual proxies. Please let me know if you have any thoughts.

Thanks!
Mark

[rohitk1609]

This would help you https://support.qlik.com/articles/000047225

If a post helps to resolve your issue, please mark the appropriate replies as "Accept as Solution" or Like it.
Best,
Rohit

[LikhithSMK]

Hello All,

We have a requirement to install a QlikSense cluster for RND purpose.

We have 2 servers one for CENTRAL and another for ENGINE. We do not have a Service account or a user account in common to these two servers. Can we still install the cluster by creating local administrator accounts in each server?

[rohitk1609]

I believe using a common service account for Qlik server is best practice. You can try with different user but I don't recommend it

[prasanthanr]

Qlik Sense Multinode Deployment, Load Balancing and Fail Over Configuration

Qlik Sense Site has 4 servers and all those 4 servers are used as follows;

1.  Central Node – Host the applications
2.  Proxy Node – To work as a load balancer
3.  Dedicated server to host the Database & File share
4. Fail over Node – For high availability

I am trying to do the High Availability solutions here!!! and regarding this I have few queries and It will much helpful if you could assist me. My queries are;

1) We have a single qlik sense site license and how do we configured Failover as a passive candidate? 

2) How do we make sure whether the configured failover is in active state or Passive state?

3) Load balancing configuration for the above scenario?

[rohitk1609]

Hi Prasanthanr,

Answers to your questions::

1. No you don't need any new licenses. you can create a cluster of 12 servers in which failover candidate is one among them.

2. Stop central node services and check fail over candidate becomes master node. You can check by going to nodes=> select column Master Type.

3. Depends on your requirement what do you want to achieve  

If a post helps to resolve your issue, please mark the appropriate replies as "Accept as Solution" or Like it.
Best,
Rohit

[prasanthanr]

Dear Rohit,

We are trying on a load balancing + high availability  and a solution entirely focusing on high availability. Below are the tests that we have done.

Testing 1 - HA and Load balancing solution  

In this solution we are having a proxy node dedicatedly for the purpose to load balancing the Central Node and the Failover Node. Dedicated server to run the database and for the files hare.

1. Central Node – Host the applications
2.  Proxy Node – To work as a load balancer 
1. This proxy node has a public domain and public IP
2. We have added both these IP and domain to the host white list of the default "Virtual Proxy of Proxy Node"
3. Also "Central Node" and "Fail-over Node" added as  the Load Balancing nodes in the default "Virtual Proxy of Proxy Node"
3. Fail over Node – Running all the services
4. Dedicated server to host the Database & File share

when we tried accessing the  "Qlik Hub" and "QMC" using the white listed public IP or domain, Hub is functioning perfectly but when accessing the QMC it is showing an error that "Request to the Server was aborted".

My queries are;

1) We couldn't access QMC via the public domain or IP via the virtually proxy of the proxy node. However, we could access the QMC locally in the central node server via the virtual proxy of the central node using the hostname. What might be the reason for this? We have removed and reinstalled the certificates also.

Testing 2 - HA Solution  

In this scenario we have just removed the "Proxy Node"  and altogether we have now three nodes including the failover and the central.

1. Central Node - 
1. This Central node has a  public IP
2. We have added the public IP to the host white list of the default "Virtual Proxy of the Central Node"
3. Also "Central Node" and "Fail-over Node" added as  the Load Balancer on the default "Virtual Proxy  of the Central Node"
2. Fail over Node – Running all the services.
3. Dedicated server to host the Database & File share

In this above scenario we also could able to access  the "QMC" & "Hub" via public IP listed in the "Host white list" under the default virtual proxy of  the Central node.  

Failover Testing:

Once after shutting down all the services of the Central Node, after 10 minutes failover node is taking over but at that time we couldn't able to access the qlik sense site via the white listed IP of the central node proxy. However, we could access the Qlik Sense site via the IP of the virtual proxy of the failover node. Is it mandatory to use an external load balancer for this scenario?... Please explain the internal process how the failover takes over when the central node goes down.

Kindly read out these above mentioned tried solutions, guide us on what could be done further

[rohitk1609]

@prasanthanr 

Answer to your query: 1) We couldn't access QMC via the public domain or IP via the virtually proxy of the proxy node. However, we could access the QMC locally in the central node server via the virtual proxy of the central node using the hostname. What might be the reason for this? We have removed and reinstalled the certificates also.

Answer: When you say you couldn't access QMC from virtual proxy, Here, can you access hub? if not , did you check your public DNS, did you add virtual proxy IP address or DNS host name to white list host ids in virtual proxy section of Proxy server?

Testing 2 - HA Solution  

Load balancing says, when you current master or central node is down , failover server takes change but shut down proxy server is not the right way of testing. You should stop central node services and test faillover candidate takes charge or not? This is how to check load balancing.

If a post helps to resolve your issue, please mark the appropriate replies as "Accept as Solution" or Like it.
Best,
Rohit

[BeeGees]

Hi Rohit,

I have site with just central * 1x rim node. Only on central node reloads are performed, rim node is just for user-driven traffic.

I would like to know if it is possible to distribute load unevenly? Right now users are 50% on Central node & 50% on Rim node. Would 80/20 be possible? Since central is handling reloads i would like to take off some work of his shoulders with user traffic.

Thanks for info!