NP scheduler or Messenger (RabbitMQ) Service not starting, NPrinting Run Verification Designer Preview issue, NPrinting Engine Offline

[Sonja_Bauernfeind]

Symptoms:

• Scenario A: When installing or upgrading  the Run Verification will not run after creating an App Connection.
• Scenario B: The Engine Service stops immediately after a restart or it works but the Engine in the NPrinting web console stays offline.
• Scenario C: NPrinting Services (NP Engine, Web Engine, Scheduler services are not starting or fail to remain in a started state.

Scenario A:  All NPrinting services 'may' be are running normally.

• Related error found: in Web Engine log: "Close: Error closing compress writer section=compress type=gzip error="

Scenario B: The Engine in NPrinting Web Console is offline and the activation fails on adding the password for the certificate. In some cases the Engine service stops immediately after a restart, in some others it keeps running. The Web Engine logs shows this error:

• The Web Engine logs show this message:
  Exception serving the request http://localhost:4996/npe/engines/bf417c4a-4ad7-4d52-9edd-65f5390fe98f/certificate System.Security.Cryptography.CryptographicException: Invalid provider type specified.↵

Scenario C: (Most Common) NP Engine may be found to be in an 'Offline' status and or NP Scheduler service not starting for fails to remain in a 'started' state

• in the NP Engine, Web Engine and or Scheduler logs check for error "Web Engine client certificate not found in store. Generating a new certificate from RabbitMQ CA key"

Environment discovered in:

• Qlik NPrinting April 2019 and later versions

Affecting:

• Any NPrinting version

What is the Cause?

• cookie mismatch due to a different user installing the NPrinting server and engine that is not the current NPrinting service account.
• a missing RabbitMQ user.  ie: client_scheduler.
• NPrinting server certificates are missing or need updating.
• The NPrinting Engine Service users has not full access to the C:\ProgramData\Microsoft\Crypto\RSA\MachineKeys folder.

Resolution:

Please upgrade to June 2020 or newer versions of NPrinting. If the issue persists, please check the steps below:

 

Part 1: Check Rabbit MQ User Permissions

Diagnosis:

• Open a new command prompt as an Administrator
• Navigate to the RabbitMQ sbin folder: %ProgramFiles%\NPrintingServer\rabbitmq_server-3.x.x\sbin

navigate manually to %ProgramFiles%\NPrintingServer\rabbitmq_server-3.x.x to determine to determine the values for 'x'

For example: %ProgramFiles%\NPrintingServer\rabbitmq_server-3.7.24 (if NPrinting June 2020)

• Run the following command: rabbitmqctl.bat list_permissions
• Ensure the output looks similar to the following:

remote  .*      .*      .*
client_engine   .*      .*      .*
client_scheduler        .*      .*      .*   
client_webengine        .*      .*      .*

If November 2020 and later versions, you should also see:
client_audit    .*      .*      .*

• If the output of the rabbitmqctl.bat list_permissions test appear as shown above, then NPrinting is running normally. if the test does not show the above information but rather shows node errors or access denied or other errors, proceed to next point

 

The solution to Part 1:

• Copy the .erlang.cookie file from the %SystemRoot% folder (C:\WINDOWS\system32\config\systemprofile) and place it in the %USERPROFILE% folder (ie "C:\Users\installer_user_account') of the domain account used to install NPrinting.
• Restart all NPrinting services and retest to check if the issue is resolved. If not resolved and there are still missing Rabbit users as per above, proceed to the next part below:
• As a precaution, back up/make a copy of any .erlang.cookie files that will be overwritten

 

Part 2: Insert missing Rabbit MQ users, permissions and repair certificates

Diagnosis:

• Perform the diagnosis step found in Part 1 above again
• If the output of the rabbitmqctl.bat list_permissions test is missing any of the four rows shown below, proceed to "Solution" in next point to insert the missing rows/permissions as needed,
• Open Windows certificates manager by clicking on Windows start and writing "Manage Computer Certificates". Notice any missing NPrinting client user (engine, scheduler, web engine). The  certificates are in  "Certificates-Local Computer>Personal>Certificates.

remote  .*      .*      .*
client_engine   .*      .*      .*
client_scheduler        .*      .*      .*   
client_webengine        .*      .*      .*

If November 2020 and later versions, you should also see:
client_audit    .*      .*      .*

 

The solution to Part 2:

• Log on to the machine as the NPrinting Engine user and check that this user has full access to the C:\ProgramData\Microsoft\Crypto\RSA\MachineKeys folder. This step is necessary to proceed with the solution. The certificates can't be recreated if the users has not the correct access level to the folder.
• Find the path to the RabbitMQ folder by navigating to "C:\Program Files\NprintingServer"
• Replace 3.x.x below with your version of RabbitMQ. (For example Nov. 2020 NPrinting rabbitmq is 3.8.3 and June 2020 is 3.7.24)
• Run the following commands to insert the missing rabbit users and repair certificates in the local computer certificates repository and the NPrinting server PEM certificates: 

RabbitMQCertificatesGenerator.exe -p "C:\Program Files\NPrintingServer\rabbitmq_server-3.x.x" -c "C:\ProgramData\NPrinting\certificates" --generate-ec -f

Final Steps:

• Uninstall and reinstall the NPrinting Engine software (make sure to write down the certificate password that you use when installing the NP engine. You will need it in the next step).
• Next, delete and re-add the NPrinting Engine in the NPrinting Web Console (Admin>Engine Manager) and click resend the certificate. This will send the certificate to the Windows local computer certificate repository. Notice that the Engine may stay offline until the machine is rebooted.
• Reboot the NPrinting Engine server.

Notes:

• Some older NPrinting versions lost RabbitMQ users or may not have been inserted normally. This behavior has been resolved in June 2020 and later versions of NPrinting
• If upgrading from older versions of NPrinting (April 2020 and earlier), in some edge case situations, this issue may be experienced.

remote  .*      .*      .*
client_engine   .*      .*      .*
client_scheduler        .*      .*      .*   
client_webengine        .*      .*      .*

If November 2020 and later versions, you should also see:
client_audit    .*      .*      .*​

Related Information:

If the above resolves NP Engine issues but does not restore normal operation of the NPrinting Messenger service, please check the following help page which describes how to remove and reinstall the RabbitMQ service.

• https://help.qlik.com/en-US/nprinting/Content/NPrinting/Troubleshooting/Qlik-NPrinting-Messaging-Ser...