Bad written integration WebServices can block all browsing for a PeopleSoft Application on a bad configured Application Server.
When an Pub/Sub Application server is configured with a timeout equal to zero for the PSAPPSERV service, it can be blocked and not recycling process will happen. Then you can reach a point with not PSAPPSERV available for navigation.
You can check the App server state on tuxedo command line, it shows an integration service event:
A session query on the DB shows a “JavaClient” (Java application used to WebServices test) on the CLIENT_INFO column.
Andrés Caro
PeopleSoft Skilled Professional 