Failover candidate

[vajid4525]

Hi Team,

I need your help to clarify a query on Failover candidate.

As far as I understood a failover node should be a scheduler node also, else if all services are enabled, tasks will start running in that node which can't be restricted without any additional custom load balancing rules. Even though proxy service is enabled in failover node, end users can be restricted to another node by virtual proxy load balancing. .

Please let me know whether my understanding is correct or not.

Thank you

[Chip_Matejowsky · Accepted solution]

Hi @vajid4525,

For a node to be a failover candidate, it must run the following services:

• Qlik Sense Repository Service
• Qlik Sense Engine Service
• Qlik Sense Proxy Service
• Qlik Sense Scheduler Service

If the failover candidate becomes the active central node, it will also automatically become the manager scheduler.  Because the scheduler service must be active, the failover candidate will function as a worker scheduler and will receive reload jobs.

Correct, if you have VP load balancing rules in place, you can restrict end users to specific nodes.

See the following Qlik documentation from the online Help and Knowledgebase:

• Configuring failover for central node resiliency
• Qlik Sense Failover Central Node:  Requirements and Considerations

Best Regards

[Steve_Nguyen]

For Replicate install on Cluster, the cluster need to be Active/Passive .

[giociva]

My 2 cents on this, as I'm facing that situation these days...

In an typical enterprise-scaled scenario, I tend to have dedicated Central / Failover nodes and use them just for management purpose (= I do not want reload task being started on failover central node)

Now, with default LB Rules you cannot exclude the failover central node from running reload task

Something like  isFailoverCandidate = "true" would be useful for this purpose, but unfortunately is not a valid condition for a node.

To achieve this I create I Custom Property @isFailoverCandidate with value True and assigned this to both central and failover. Then I created the LB Rule and configured the Active Central as Scheduler Manager. In case of failover, the LB Rule will exclude the new failovered central node from reload tasks.

Best,

[TusharDev_Qlik]

@giociva can't we set it failover node as only Manager and not (Manager and Worker) similar to Central so that it will only be used to manage reload tasks and not run them.

[TusharDev_Qlik]

Thank you for your solution here. Only one doubt I have is how do we acheive the QMC url failover? When the central server goes down, the fqdn used to access qmc will not be functional so how can we manage same fqdn for both Central and Failover node so the end user will not face any issue if central goes down.