SA-14820

Summary

Errors - doWithRequestorOrThreadLocked error and RequestorLockException are periodically generated in the log file. Errors with "Connection to http://pdn.pega.com refused" are also observed.

Error Messages

com.pega.pegarules.pub.PRRuntimeException: doWithRequestorOrThreadLocked could not obtain requestor instance from H1234567890ABCDEF
~~~
com.pega.pegarules.pub.context.RequestorLockException: Unable to synchronize on requestor within H1234567890ABCDEF 120 seconds
~~~
com.pega.pegarules.pub.services.ConnectorException: Caught unhandled exception: com.pega.apache.http.conn.HttpHostConnectException: Connection to http://pdn.pega.com refused
CAUSED BY: Caused by: java.net.ConnectException: Connection timed out
 

Steps to Reproduce

Not Applicable

Root Cause

A defect or configuration issue in the operating environment.  The server in question is behind a firewall.  Each requestorLockException generates a thread dump and indicates the thread that is locked. The thread locked in this case is waiting for a response from a Connect-REST to the PDN, but is not receiving a response (including an HTTP response halting the connection) due to firewall configuration.
Any system behind a firewall should be configured not to make external connections in this manner.

Resolution

Perform the following local-change: 

Alter the dynamic system setting, AllowAccessToExternalSystem, which determines whether the Pega 7 platform instance attempts to access the PDN.
​The default value is "true". A value of false will configure Pega to not attempt this connection, and therefore the connection does not time out and create errors in the logfile.