In some databases on my site (all of them on Linux host and 11.2.0.4 version) I noticed that SECOND_IN_WAIT column from V$SESSION or V$SESSION_WAIT has impossible high values. To be more precise, more then 47 years.
This only happens on background sessions (SESSION_TYPE='BACKGROUND').
I have some monitoring scripts that are been raised due this problem.
When I focus on DB Writers I see that all of them are normally waiting for rdbms ipc message. Ok, this is the normal behaviour. My monitoring script are not been raised in this situation.
[11g]> @dbwr_waits
PROGRA SID SPID EVENT SEQ# wait_time (s) SECONDS_IN_WAIT STATE
------ ----- --------- ------------------------------ ---------- ------------- --------------- -------------------
(DBWA) 6021 66809 rdbms ipc message 193 0,00 1528903014 WAITING
(DBWB) 6322 66811 rdbms ipc message 46961 0,00 1528903014 WAITING
(DBWC) 6623 66813 rdbms ipc message 5592 0,00 1528903014 WAITING
(DBWD) 6924 66815 rdbms ipc message 7218 0,00 1528903014 WAITING
...
But If I get some write on db file I got this situation:
[11g]> @dbwr_waits
PROGRA SID SPID EVENT SEQ# wait_time (s) SECONDS_IN_WAIT STATE
------ ----- --------- ------------------------------ ---------- ------------- --------------- -------------------
(DBWA) 6021 66809 rdbms ipc message 3893 1,99 1528903205 WAITED KNOWN TIME
(DBWB) 6322 66811 rdbms ipc message 50603 1,64 1528903205 WAITED KNOWN TIME
(DBWC) 6623 66813 rdbms ipc message 9322 1,46 1528903204 WAITED KNOWN TIME
(DBWD) 6924 66815 rdbms ipc message 10765 2,22 1528903205 WAITED KNOWN TIME
(DBWE) 7225 66817 rdbms ipc message 31151 0,40 1528903203 WAITED KNOWN TIME
(DBWF) 7526 66819 rdbms ipc message 3027 1,69 1528903205 WAITED KNOWN TIME
(DBWG) 7827 66821 rdbms ipc message 24244 2,64 1528903206 WAITED KNOWN TIME
(DBWH) 8128 66823 rdbms ipc message 18634 2,76 1528903206 WAITED KNOWN TIME
(DBWI) 8429 66825 rdbms ipc message 61980 1,79 1528903205 WAITED KNOWN TIME
(DBWJ) 8730 66827 rdbms ipc message 38905 2,84 1528903206 WAITED KNOWN TIME
(DBWK) 9031 66829 rdbms ipc message 63753 2,99 1528903206 WAITED KNOWN TIME
(DBWL) 9332 66831 db file parallel write 19677 -0,01 1528903203 WAITED SHORT TIME
(DBWM) 9633 66833 rdbms ipc message 35403 1,48 1528903204 WAITED KNOWN TIME
In this situation my monitoring script thinks I have a stuck write on storage, and the 24/7 DBA is alarmed.
I could not find no doc or bug about this problem, except a very old one, for 8.1.6 RDBMS version.