NPrinting erratic behavior. Publishing works flawlessly, then keeps hanging. Help?

[Maarten_Bitmetric]

We have recently migrated from NPrinting 16 to Qlik NPrinting May 2022 SR4. Unfortunately after a great start we are experiencing erratic behavior:

At certain points the reports all run perfectly. At some moments it will take a long time to run and at certain points we kill them, since they seem to be running forever:

What could cause this? We are seeing the following in the event log:

Faulting application name: Qv.exe, version: 12.20.21200.0, time stamp: 0x5f31048c
Faulting module name: Qv.exe, version: 12.20.21200.0, time stamp: 0x5f31048c
Exception code: 0xc0000409
Fault offset: 0x0000000001acd06c
Faulting process id: 0x39e8
Faulting application start time: 0x01d979f394ac0141
Faulting application path: C:\Program Files\QlikView\Qv.exe
Faulting module path: C:\Program Files\QlikView\Qv.exe
Report Id: bbcd51ba-b892-490d-b7e9-21e1dfd07592
Faulting package full name:
Faulting package-relative application ID:

Or:

Faulting application name: Qv.exe, version: 12.20.21200.0, time stamp: 0x5f31048c
Faulting module name: Qv.exe, version: 12.20.21200.0, time stamp: 0x5f31048c
Exception code: 0xc0000409
Fault offset: 0x0000000001acd06c
Faulting process id: 0xa2ec
Faulting application start time: 0x01d97b0b7e014c72
Faulting application path: C:\Program Files\QlikView\Qv.exe
Faulting module path: C:\Program Files\QlikView\Qv.exe
Report Id: 389abf69-5fee-406b-94e1-14ab881fc1ea
Faulting package full name:
Faulting package-relative application ID:

So it seems there are problems with opening QV. 

If we try to restart the services when it is hanging the NPrinting Engine is unresponsive, so we have to restart the server. After the restart everything works perfectly again. Sending all reports in a few minutes. 

What could cause this or where to start looking? How come that one moment all reports (+- 30 publish tasks) are send in a matter of minutes, and the next moment they keep running for hours.

[Lech_Miszkiewicz]

Hi @Maarten_Bitmetric 

You say: What we noticed is that the QlikView server is running out of memory at times, although why is not clear yet.  Are you experiencing this when NPrinting is running its task? How many CPU cores do you have on your new NPrinting server. Asking that as it will determine number of parallel sessions to QlikView NPrinting will be able to establish hence put parallel intensive pressure on QlikView server resources. 

Given how NPrinting works it is quite possible that you have qvw files unoptimized for its use. Note that NPrinting will clear all selections and may try to preview objects in cleared state which are also present on hidden sheets. This can cause huge resource consumption if those object are not optimal from typical QV development point of view. 

In other words:

• make sure your qvw does not have any unsupported objects as document on help website
• make sure you can browse through all QlikView sheets (also hidden ones) without worry that you will have any resource or calc time issues
• make sure you dont have any hidden objects which have the same problem
• all NPrinting objects which are not required for users should be minimized which will allow for much faster NPrinting performance and possibly much smaller resource consumption

Your last sentence is again unclear: "After setting the server service on the qlikview server, the memory went down and everything started to run again, including the new NPrinting." Having a NPrinting on the QlikView server is not supported and you will have issues in the future if that is the case you are describing. Apologies if I misunderstood you though.

cheers

[Lech_Miszkiewicz]

In addition - I would say you should have dedicated user account as well. If for some reason you are using the same QV app (using QVP connection) from old and new NPrinting your sessions will be interrupted - same as you would try to open QlikView app from access point using the same account from 2 different machines.

[Maarten_Bitmetric]

Hi Lech,

I meant after resetting/restarting the qlikview server service on the qlikview machine. All nprintings and qlikview are hosted on separate machines. The new NPrinting server has 16 cores, the Qlikview server has 32. 

I understand what everyone is saying about optimizing the QVW, but I cannot see if they are unoptimized how one moment all reports are send in a matter of minutes, while the other moment it causes the Qlikview machine to run out of memory. To me it seems the problem lies in the Qlikview machine running out of memory and the erraticness of this behavior. 

[Maarten_Bitmetric]

This sound logical, however the new NPrinting uses open in server, while the old one opens directly. Does this also conflict?

[Lech_Miszkiewicz]

In theory it shouldn't conflict, but!!! Since your old one opens document locally it can cause resources issues which can explain why you are running out of resources.

The situation you are currently in is hard to troubleshoot as you have many potential factors causing issues. There is no way you can have supported configuration to run both NPrinting version supported due to QlikView version compatibility. Either one or another is not meeting supported setup criteria so to me it is a starting point of troubleshooting. I never allow for unsupported configuration and if I am forced to be in one I take no responsibility as simply it is wrong.

[Frank_S]

Hi @Maarten_Bitmetric 

Your comment "Both NPrintings are on different machines, although they share the same services account. However I don't think that will interfere with anything."

However this WILL interfere with everything and cause the very issue you are experiencing.

This is mentioned in the Migration playbook and also here as well.

Dedicated NPrinting Server & Engine Service Accoun... - Qlik Community - 1716056

I strongly urge you to configure a dedicated NP service account for one each of your NP environments. (and ensure that service account is also NOT used by any other QlikView or NPrinting environment).

Kind regards...

[Maarten_Bitmetric · Accepted solution]

Thanks for all the suggestions. We have not yet upgraded, since some essential reporting is still needed by the customer for this week. However we have found that the QlikView server running out of memory might have been (part of) the problem. Last week we scheduled a task which restarts all Qlikview services every night to stop it from running out of memory and haven't had any issues since...