Skip to main content

This content has been archived and is no longer being updated. Links may not function; however, this content may be relevant to outdated versions of the product.

Support Article

PEGA0026 alerts display after deadlock on external database



After a deadlock occurs on an external database, PEGA0026 alerts display and connections pile up on the database .

Error Messages

Not Applicable

Steps to Reproduce

  1. Launch the System Management Application (SMA) node.
  2. Navigate to the database management.Select pega_work.
  3. Click Database details. This displays 40-50 connections in the Pega managed connection column.

Root Cause

A defect or configuration issue in the operating environment. 
Pega managed the external data source The application server did not manage the external data source and the connections. Hence, connection pooling and validation were not used.


Make the following change to the operating environment: 
  1. Add the external data source to the Tomcat context.xml similar to how it is added for the jdbc/PegaRULES data source. Set the minimum and maximum connections
  2. Add the connection validation in the pool using the below:


For Tomcat 8, the default Database Connection Pool (DBCP) factory is problematic. The below factory is used with Tomcat 8. 


Published January 4, 2019 - Updated October 8, 2020

Was this useful?

0% found this useful

Have a question? Get answers now.

Visit the Collaboration Center to ask questions, engage in discussions, share ideas, and help others.

Did you find this content helpful?

Want to help us improve this content?

We'd prefer it if you saw us at our best.

Pega Community has detected you are using a browser which may prevent you from experiencing the site as intended. To improve your experience, please update your browser.

Close Deprecation Notice
Contact us