Some time ago I had an issue with some jobs running for 64 days. Cool han?
All jobs names were AQ$_PLSQL_NTFN_%. All activity of jobs were related to SQLID f7zggdz9p7bhk in wait event “Streams AQ: waiting for messages in the queue”.
# SQLID f7zggdz9p7bhk: begin SYS.SCHEDULER$_JOB_EVENT_HANDLER(context => :1,reginfo => sys.aq$_reg_info(:2, :3, :4, :5, :6, :7),descr => sys.aq$_descriptor(:8, :9, :10, sys.msg_prop_t(:11, :12, :13, :14, :15, :16, :17, :18, sys.aq$_agent(:19, :20, :21), :22, :23), sys.aq$_ntfn_descriptor(:24), :25, :26), payload => :27, payloadl => :28); end;
Reviewing on MOS, found a match to Bug 20528052 – Many AQ$_PLSQL_NTFN jobs executed affecting database performance (Doc ID 20528052.8).
The root cause is procedure SYS.SCHEDULER$_JOB_EVENT_HANDLER keep waiting AQ PL/SQL Notification callbacks associated with scheduler job email notifications for messages in “SYS”.”SCHEDULER$_EVENT_QUEUE” which no longer exist.
From MOS, this can be easily solved with fix for Bug 16623661 – No email notification is sent by scheduler, wich is included in 126.96.36.199 (base) and affect versions 188.8.131.52 and later.
Also from MOS, and which I did, is drop these jobs. The problem is these jobs just restart and have the same problem again after automated recreation.
So, apply the fix or upgrade your database. 😉
Some related references:
Bug 20528052 – Many AQ$_PLSQL_NTFN jobs executed affecting database performance (Doc ID 20528052.8)
AQ$_PLSQL_NTFN Scheduler Jobs Executed in large numbers affecting Database performance (Doc ID 2001165.1)
Bug 21665897: FIX FOR BUG 14712567 CAUSES LARGE NUMBERS OF AQ$_PLSQL_NTFN_% TO BE SPAWNED
Hope it helps!