Symptoms

Oracle Goldengate monitor instance is not able to register with the Jagent with the below error:

[2025-09-23T17:11:01.063+10:00] [JAGENT] [ERROR] [OGGMON-20272] [com.goldengate.monitor.jagent.jmx.MBeansContainerImpl] [tid: StatusCollector] [ecid: 0000P_WUnVbF^64_zTO5yW1cnElJ000003,0] unable to register the OGG instance. Due to null
[2025-09-23T17:11:11.063+10:00] [JAGENT] [ERROR] [OGGMON-20498] [com.goldengate.monitor.jagent.comm.ws.NotificationsCollector] [tid: StatusCollector] [ecid: 0000P_WUnVbF^64_zTO5yW1cnElJ000003,0] Exception thrown is: [[
java.lang.NullPointerException
        at com.goldengate.monitor.jagent.comm.impl.ManagerFacadeImpl.getCachedInstances(ManagerFacadeImpl.java:299)
        at com.goldengate.monitor.jagent.comm.ws.NotificationsCollector.checkAndDeleteProcess(NotificationsCollector.java:162)
        at com.goldengate.monitor.jagent.comm.ws.NotificationsCollector.checkAndPublishRegisteredAndDeletedProcess(NotificationsCollector.java:150)
        at com.goldengate.monitor.jagent.comm.ws.NotificationsCollector.run(NotificationsCollector.java:80)
        at java.lang.Thread.run(Thread.java:750)

]]

Solution

1. Check Jagent config file as per “GGMON-20272:OGG Monitor Instance Is Unable To Register The OGG Instance Due To Null (Doc ID 2618440.1)”
   
2. If step 1 is not working and the Monitor Agent is used by Enterprise Manager (OEM).
   
   Make sure to bounce the Manager, then restart JAGENT and PMSRVR.

GGSCI > stop JAGENT
GGSCI > stop PMSRVR 
GGSCI > stop *
GGSCI > stop manager
GGSCI > info all       # all should be stopped    
GGSCI > start manager
GGSCI > info all       # all are up running
GGSCI > start JAGENT
GGSCI > info all       # PMSRVR should be running as well