1. What is the recommended Load balancer for Qlikview in clustered environment . do we need to install external Load balancer ?
2. Attached Qlikview document in relation to san / nas. If you see the doc, references “Windows based NAS” all over the place which basically means a file share that windows servers can access.
I think we need to define what they mean by “Windows based NAS” as that is really only implying that they support CIFS / SMB and not NFS because windows clients can do NFS as well too. There is nothing in the document that is clearly spelling out that a NAS that can provide windows file shares won’t work and the statement below doesn’t provide much technical detail.
QLIKVIEW SERVER FILE STORAGE CONFORMITY
QlikView Server currently only conforms with Windows File Shares. This means that storage must be owned, governed and shared by a Windows instance. The underlying storage type should not matter.
For the load balancer, depending on the load you expect and the sizing of the servers, I would go for the external load balancer. But it's not a requirement.
For thousands of users I have deployed an AWS ELB (it's a blackbox with very limited resources and configuration) and it works well.
For the storage part, read "Windows based" not even as CIFS/SMB but rather "only NTFS", the native Windows filesystem. It could be a LUN, as long as it runs NTFS.
It does not say it doesn't work because it does work, but it is not supported, so if there is an issue with QlikView, which is highly sensitive to hiccups in network latency (depending on the version, extremely highly sensitive), Qlik Support may ask you to deploy on a NTFS file share to see whether the issue can be reproduced or it was due to the network storage.
In my experience, few small files will work just fine over a network, as long as the connection is good, basically the storage device and the QlikView server are on the same LAN. And in theory, any size of files with any concurrency scenario would work (concurrency is very important, basically every click users do and every login that happen is stored into PGO or Shared files).
Also in my experience, using a NAS made the system crash under heavy load with either thousands of users or files using several GBs, while using local disks didn't.