Summary

Inconsistencies in rule resolution results were reported with rule resolution caching across multiple JVMs. If you installed HFix-6861, a problem can occur if, on the Harness form, in the Completing Scripts and Styles tab, you have selected Generate harness-specific CSS to generate the style sheet based on CSS selectors used by the harness. This setting is intended to boost performance when custom styles are applied. However, a thread deadlock can occur that causes inconsistent, partial results in the rule resolution cache. Applying HFix-7038 corrects this problem along with resolving issues with Application-based Assembly Cache invalidation.

Details, HFix-7038

HFix-7038 corrects the thread deadlock issue introduced by HFix-6861 and delivers the changes provided by HFix-6861 to resolve problems with invalidation of assemblies during Rule Import or rule editing. The hotfix delivers new versions of the System Management Application WAR and EAR files, prsysmgmt.war and prsysmgmt.ear, which now provide a button that allows you to clear the memory cache of the Application-Based Assembly cache. This is convenient if you discover that the system did not properly invalidate an assembly from memory. This hotfix affects:

• Java code for Rule Application Conclusion
• Application Centric Cache Management
• Application Centric Assembly Cache
• Rule Assembly Cache
• Overridden PegaRULES Conclusion Implementation
• System Management Application

HFix-7038 has two parts:

• HFix-7038.jar, downloadable from Hotfix Self-Service and installable by Update Manager
• HFix-7038.zip, obtainable from Pegasystems Global Customer Support (GCS)

When you download HFix-7038 from Hotfix Self-Service, the DL-####.zip that you receive contains the HFix-7038.jar file and the JAR files of its dependent hotfixes (Additional Related Hotfixes). You install the DL-####.zip file using Update Manager.

The HFix-7038.zip file that you receive from GCS contains updated PegaRULES System Management Application (SMA) files for all supported application servers:

The HFix-7038.jar and HFix-7038.zip files provide the following improvements to functionality:

• A change to invalidation logic that eliminates the scenario causing the thread deadlock in Application-based Assembly caching, a defect introduced by HFix-6861.
• A new Clear Memory Cache button on the Application Centric Cache Management main screen of the System Management Application to clear the memory cache without restarting the JVM.
• Correct sizing of the overridden conclusion cache, for which symptoms were seen in the System Management Application.

Installing HFix-7038

To install the HFix-7038.jar file and deploy the components delivered in the HFix-7038.zip file:

1. Back up the system, as advised before installing any hotfix.
2. Go to Hotfix Self-Service, select HFix-7038, and download the DL file.
3. Install the DL file using the Update Manager via the menu choice Install Hotfix.
4. Do NOT select Perform Auto Commit. You will have a chance to commit the selected hotfixes after you have tested them.

   

5. After you have installed the hotfix, restart each server node.
6. In the System Management Application, open the "Application Centric Cache Management Version 1.0" window to see the existing options:
7. Remove the cached prsysmgmt module on the application server.
   1. Be sure to do this before proceeding to the next step because old versions of prsysmgmt EAR and WAR files that are cached on the application server will interfere with the deployment of the new prpsysmgmt module.
   2. Check the work directory in the Pega application server profile for old versions of cached prweb and prsysmgmt EAR and WAR files.
   • For example, JBoss EAP 5.1.2 caches some of the WAR and EAR file contents in a work directory.
     • If you discover old versions of the EAR and WAR files cached in the work directory in the Pega application server profile, you must stop the application server, remove the old directories corresponding to the newly deployed WAR or EAR files, and restart the application server.
     • If you fail to find all old cached WAR and EAR files, the new System Management Application buttons described in Step 9 will not display.
   • Apply any alternative best practices for the application server regarding removing/clearing deployed artifacts and redeploying artifacts. Do this to ensure that old deployed WAR and EAR files are cleared or fully removed so that the new System Management Application will work as expected after you apply the hotfix.
8. Deploy the new prsysmgmt.war or prsysmgmt.ear for your application server that was delivered in the HFix-7038.zip file.
9. After you deploy the new prsysmgmt module, you see the new buttons, Clear Cache and Clear Memory Cache, in the Application Centric Cache Management Version 1.0 screen:

The new Clear Memory Cache button allows you to clear out the memory cache without restarting the JVM.

With these changes to Application Centric Cache Management, you should not need to restart the JVM or use the Clear Memory Cache button. However, this button has been added to the System Management Application to provide a consistent set of features to manage the Application Centric Cache. 

Be sure to test your system thoroughly. Contact GCS if you have any questions or concerns.

Additional Information

When to use - and when not to use - ABA mode for application performance

Harness form, Completing the Scripts and Styles tab

Understanding caching