Troubleshooting Timeout Issues with PI Data Archive: The Impact of MaxConnIdleTime

PI System administrators and users sometimes face mysterious disconnection issues when working with client applications like PI System Management Tools (SMT), PI ICU, or PI DataLink. A common scenario involves working seamlessly in a client application, only to find out—after a period of inactivity—that the application can no longer connect to the PI Data Archive. If this happens consistently, especially after a fixed idle period (such as 20 minutes), a key suspect emerges: the server-side idle connection timeout setting.

Understanding the Problem

Users report that after working in a PI client application and leaving it idle (without closing it), they return after 20 minutes to find the application unable to connect to the PI Data Archive 2015 R2. This issue also affects entire teams and has persisted over several months, pointing to a systemic, configuration-related trigger rather than isolated client-side problems.

Investigating Server Timeout Settings

A helpful suggestion is to check the PI Data Archive server's Net Manager - MaxConnIdleTime tuning parameter. This setting instructs the PI Net Manager (PINetMgr) how long to wait before closing idle client connections.

• Default Behavior: The MaxConnIdleTime parameter should be set to blank (interpreted as 0), indicating that idle client connections are never closed automatically.
• Changed Value: If you find that this parameter has a numeric value (such as 1200 seconds, or 20 minutes), then the server is set to disconnect idle clients after that time.

How to Check and Adjust MaxConnIdleTime

1. Open PI System Management Tools (SMT): Navigate to the relevant PI Data Archive server.
2. Find Tuning Parameters: Expand the list and look under [PI Server] > Tuning Parameters.
3. Locate MaxConnIdleTime: Look under the 'Net Manager' section.
4. Adjust the Value: If there is a value (other than blank/0), clear the field (blank it).
5. Save Changes and Restart Server:
   • Changes only take effect after a restart!
   • Use the scripts pisrvstop.bat and pisrvstart.bat in the PI\adm folder to restart the PI Server.
6. Verify Functionality: Monitor client applications to ensure the issue is resolved.

⚠️ Important: Check with other admins before changing tuning parameters—there may be intentional reasons for the previous setting.

Additional Troubleshooting Using Logs

If adjusting the timeout parameter does not resolve the problem, export and review the PI Message logs (available through PI SDK Utility or SMT) after reproducing the issue. Look for specific disconnect messages that can further narrow down root causes.

Real-World Example

One user investigated their settings and was surprised to find that a timeout value had indeed been set, contrary to their expectations. Simply reverting to the default blank value resolved the persistent disconnect issues for their entire team.

Conclusion

Timeouts between PI client applications and the PI Data Archive are often traceable to the MaxConnIdleTime setting. Maintaining the default configuration usually ensures smoother user experiences. Always document and communicate any changes to server parameters with your administration team to avoid unintended consequences for other systems or users.

Have you encountered similar PI system timeout issues? Share your experiences and solutions below!