Control panel is not loading. All core and UI services are running on the management node and UI servers. In the
pui.log file on the UI nodes it is seen that suddenly requests stopped being responded:
12:17:45.190 [default task-182] INFO EJB - ProxyFileManagerRemote::listProxyFiles >>> entry 12:19:21.907 [default task-58] INFO EJB - ConfigurationManagerRemote::getParam <<< exit [1959279 ms] 12:19:21.908 [default task-58] INFO EJB - NavServiceRemote::getLatestChanges >>> entry 12:19:21.908 [default task-185] INFO EJB - ConfigurationManagerRemote::getParam >>> entry 12:19:21.923 [default task-101] INFO EJB - BrandingManagerRemote::getBrand <<< exit [1946093 ms]
The root cause of the OA panel outage is on the management node side and related to PAU/Jboss services.
OA 7.0/7.1 has a pool of 10 EJB threads, which are used by OA tasks and serving UI requests at the same time. In case all the threads are busy, UI requests cannot be properly processsed.
This behavior was changed since OA 7.2: background tasks and UI requests now use different thread pools. In order to avoid the issue in the future, it is recommended to upgrade OA to 7.2 version or higher.