Manage NLINK ADC to SAP Solution Timeouts

Owned by Darcy Curtin
Last updated: Apr 20, 2017 by Rakesh
3 min read

Problem - The processing of ADC Event takes a long time and users are getting error.

  • On the device (browser), get error "Please report the following error: Server Error" and users need to restart the application.
  • There is error in NLINK event log: "Timeout occurred while waiting for processing to be completed"

Solution

The problem typically occurs when a specific ADC Event takes a long time complete processing and send back a response to the scanner. The processing of the NLINK Event has to occur within the time specified in the "Synchronous Message Timeout" value. This setting is found in the NLINK Management Module (NMM) or NLINK Configuration Module (NCM) under the System Properties. By default it is set to be 60 seconds.

If processing of the Event takes longer than this time period, then change the value to a suitably higher value. But it is recommended that the underlying reason for the Event taking a long time be addressed rather than simply changing this value to be higher.

This value indicates the upper bound for the timeout if the Event does not complete. If the Event takes a lesser time to process, then the timeout will not be used.

Problem - Users sessions are getting terminated after some idle time

Users are getting terminated and reset back to logon page with error message. Message on logon page can vary

  • Message on logon screen says "Your Session has expired[Status code 440]! Session Expired" message.
  • Message on logon screen says "Error posting data [Page]: The request failed with HTTP status 401: Unauthorized.Status: Unauthorized"
    • There can be corresponding entry in NLINK Event log  "User 'XYZ' has been automatically logged off due to inactivity". 

Solution

The NLINK ADC to SAP Solution will automatically log users off if there is no activity for a specified period of time. If this timeout is not managed and set properly, users can be logged-off sooner than they would like. There are 3 separate timeout values in the NLINK ADC to SAP Solution that need to be set properly. The first is set using NMM or NCM and the other two are set through Microsoft’s IIS Manager. 


NLINK Idle Session Timeout (minutes) 

This setting is found in the NMM or NCM under System Properties. By default it is set to 60 minutes.

IIS Session State Timeout (minutes)

Use the Microsoft IIS Manager, find the ADC Website/Application (under the default website).

  1. Select the ADC web site under “websites” and then select "Session State" and open session settings.
  2. Set the Session Timeout value

IIS Application Pool Idle Timeout (minutes)

Find out which Application Pool is being used for the ADC Website/Application under the IIS Manager Advanced Settings. Locate this Application Pool under the Applications Pool tree. Under its Advanced Settings, set this timeout value.

  1. Click on the Advanced settings of the Application Pool used for ADC 
  2. Set the “Idle Timeout” value under the “Process Model” 

If, for some reason, any other web sites/applications are using this Application Pool, a new Application Pool can be created and assigned to ADC.

Be sure to set the IIS Session State Timeout and the IIS Application Pool Idle Timeout less than or equal to the NLINK Idle Session Timeout