SA-21946

Summary

During performance and load testing, when number of concurrent users reach above 90, system stops responding and shows errors in the logs: "Error while decoding access group (reqURI_Not_Found) " .

Pega has HTTP Context URL rewrite enabled.
 

Error Messages

[2016-03-23 12:37:03] 2016-03-23 12:37:03,762 [fault (self-tuning)'] [ STANDARD] [ ] [ ] (ernal.authorization.ContextMap) ERROR vg04f4xr.dc-ratingen.de|vg04a9xr.dc-ratingen.de - Error while decoding access group (reqURI_Not_Found)
[2016-03-23 12:37:03] javax.crypto.IllegalBlockSizeException: Input length must be multiple of 8 when decrypting with padded cipher
[2016-03-23 12:37:03] at com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:750)
....

Steps to Reproduce

1. Start load testing.
2. Enable HTTPS offloading on Apache.
3. Observe that when load goes above 90 concurrent users, the error starts appearing.

Root Cause

A software use or operation error.

Resolution

Here’s the explanation for the reported behavior.

The load testing tool is sending incorrect HTTP request such as:
 
POST /prweb/PRServlet/action_Not_Found/!STANDARD HTTP/1.1"
 
This generates the following error message:
 
ERROR vg050fxr.dc-ratingen.de|vg04a9xr.dc-ratingen.de  - Error while decoding access group (action_Not_Found)
 
The URL is supposed to be like this:
 
POST /prweb/PRServlet/reJPeuyFEJ5ZQPkDNZN_kZbtLcvzKR1a*/!TABTHREAD0?pyActivity=ReloadSection…
 
The bold part being a hash code representing the access group.

PRPC fails to decode the access group as “action_Not_Found” is not a valid hash code to be decoded.

The load testing tool must be reconfigured to send expected PRPC HTTP request.