QlikView tasks / reloads are stuck for an infinite time. Manual intervention kills them and kicks them off again to retry. The behavior is not consistent and stalling happens randomly.
The tasks stall at a STORE command while writing to QVDs.
The failing tasks include reloads that write to QVDs and the issue is normally an indication of insufficient disk I/O performance. Qlik is investigating improvements to the default save process (internal ID ID QV-20266).
In 12.50 we introduced Asynchronous Write as a feature to speed up the storing of .qvds. However, we have noticed that in disks that perform less well, the mentioned issue can happen.
Resolution
Upgrade to the latest version of QlikView.
Workaround
A setting can be introduced which makes the QVB save writing process less aggressive. This has been successfully tested, but does come with a performance impact. The cost of applying the setting are slower reloads as the file writing speed drops to save disk functions.
To implement:
- Stop the QlikView Distribution Service and ensure that no QVB.exe is currently running
- Locate the QlikView Batch (QVB) settings.ini: C:\Windows\System32\config\systemprofile\AppData\Roaming\QlikTech\QlikViewBatch
- Open and edit the file, adding the following value under the [Settings 7] section:
EnableQvdAsyncWrite=0
- Save and close the file
- Start the Distribution Service
Note: As a workaround, in QlikView 12.50 SR3 the default has been set to 0, disabling the Asynchronous Write feature. This will result in slower, but more stable, performance.
Asynchronous Write can been enabled back by setting the value to 1, if the performance of the disk has been tested and verified to be able to handle the higher load.
QlikView 12.50 SR4 will include some improvements that should make the feature more reliable even of less-performing hardware.
We have seen a couple of places where the above fix doesn’t seem to help.
If you are experiencing this, please check the following
Is there a file called Initial.ini in the below folder,
C:\Users\<service account>\AppData\Roaming\QlikTech\QlikViewBatch\initial.ini
If there are, you need to perform the steps below. This file should have been cleaned up by the installer but under some special circumstances this doesn’t happen
Stop the distribution server service.
- Copy the content of C:\Users\<serviceaccount>\AppData\Roaming\QlikTech\QlikViewBatch\initial.ini
- Paste the content to C:\Windows\System32\config\systemprofile\AppData\Roaming\QlikTech\QlikViewBatch\Settings.ini, make sure that you still have the EnableQvdAsyncWrite=0 set.
- Save
- Rename the initial.ini (example: initial.old)
- Restart the service
Information provided on this defect is given as is at the time of documenting. For up to date information, please review the most recent Release Notes, or contact support at support.qlik.com with the ID QV-20266 for reference.
Environment:
QlikView 12.50 (April 2020) IR, SR1 and SR2
