Repeated DFW-99998 errors in OBIEE 12c? Some of them you can ignore

On OBIEE 12.2.1.1.0, you may get repeated DFW-99998 errors, such as:

<Feb 20, 2020, 3:22:08,281 PM EST> <Emergency> <oracle.dfw.incident> <BEA-000000> <incident 9116 created with problem key "DFW-99998 [java.io.IOException][oracle.bi.security.filter.BISecurityFilter.handleAnonymousSubject][analytics]">

[2019-11-15T14:40:27.643-05:00] [bi_server1] [NOTIFICATION] [DFW-40101] [oracle.dfw.incident] [tid: [ACTIVE].ExecuteThread: '12' for queue: 'weblogic.kernel.Default (self-tuning)'] [userId: <WLS Kernel>] [ecid: b98a9e33-00a2-4167-ad51-74caa842b8e3-000f2a7d,0] [partition-name: DOMAIN] [tenant-name: GLOBAL] An incident has been signalled with the incident facts: [problemKey=DFW-99998 [java.io.IOException][oracle.bi.security.filter.BISecurityFilter.handleAnonymousSubject][analytics] incidentSource=SYSTEM incidentTime=Fri Nov 15 14:40:27 EST 2019 errorMessage=DFW-99998 executionContextId=b98a9e33-00a2-4167-ad51-74caa842b8e3-000f2a75]

[2019-11-15T14:40:28.099-05:00] [bi_server1] [INCIDENT_ERROR] [DFW-40104] [oracle.dfw.incident] [tid: [ACTIVE].ExecuteThread: '12' for queue: 'weblogic.kernel.Default (self-tuning)'] [userId: <WLS Kernel>] [ecid: b98a9e33-00a2-4167-ad51-74caa842b8e3-000f2a7d,0] [errid: 4263] [detailLoc: /u01/middleware/user_projects/domains/obiee/servers/bi_server1/adr/diag/ofm/obiee/bi_server1/incident/incdir_4263] [probKey: DFW-99998 [java.io.IOException][oracle.bi.security.filter.BISecurityFilter.handleAnonymousSubject][analytics]] [partition-name: DOMAIN] [tenant-name: GLOBAL] incident 4263 created with problem key "DFW-99998 [java.io.IOException][oracle.bi.security.filter.BISecurityFilter.handleAnonymousSubject][analytics]"

Now keep in mind that DFW errors are diagnostic framework errors, and particularly DFW-99998 could mean anything, so you don't want to simply ignore all DFW-99998 errors.

But in this specific case, the error is a Java I/O exception on some OBIEE security filter:

[java.io.IOException][oracle.bi.security.filter.BISecurityFilter.handleAnonymousSubject]

After two SRs with Oracle Support, we've confirmed that these can be safely ignored.

The annoying problem is that we've been getting 0-10 entries of these in the logs on a daily basis, and the OEM Agent picks them up and alerts on them.

The only possible solution is to filter these errors out using standard WebLogic filters.