Issue

A compatibility issue might affect certain near-zero downtime update scenarios involving environments running Pega Platform '24.x or earlier releases when updating to Pega Platform ’25.1.x or Pega Platform ’26.1 releases.

During the transition period, users might experience intermittent issues with case processing until all nodes have been restarted.

Symptoms and Impact

During the update process, the keystore data format changes from JKS to BCFKS as part of the data update phase. In environments that are undergoing a rolling restart, Constellation application nodes may start looking for a keystore format that earlier releases of the Pega Platform engines do not support.

During this transition period, users might experience intermittent issues with case processing until all nodes have been restarted. The issue is limited to the period between completion of the data update and the restart of all cluster nodes. Once nodes are restarted on the target release, normal processing resumes.

Solution

Until hotfixes become available on the source Pega Platform release, perform the near-zero downtime update during a maintenance window where the system is not used until the rolling restart is completed on all nodes. This approach avoids the transitional compatibility gap and ensures uninterrupted operation.