PMON process consumes large memory while ORA-04030 reported

(Doc ID 1439907.1)

Last updated on NOVEMBER 28, 2016

Applies to:

Oracle Server - Enterprise Edition - Version: 11.2.0.1 and later   [Release: 11.2 and later ]
Information in this document applies to any platform.

Symptoms

The pmon process may grow very large or an ORA-4030 error may occur on pmon process.

The following error occurs:

Errors in file /backup/diag/rdbms/ebcqa9/ebcqa91/trace/ebcqa91_pmon_7361.trc:
ORA-04030: out of process memory when trying to allocate 10024 bytes (pga heap,kzaxins1-alloc encode xml text)
Errors in file /backup/diag/rdbms/ebcqa9/ebcqa91/trace/ebcqa91_pmon_7361.trc:
ORA-04030: out of process memory when trying to allocate 10024 bytes (pga heap,kzaxins1-alloc encode xml text)
Errors in file /backup/diag/rdbms/ebcqa9/ebcqa91/trace/ebcqa91_pmon_7361.trc:
ORA-04030: out of process memory when trying to allocate 10024 bytes (pga heap,kzaxins1-alloc encode xml text)

A Heapdump collected for PMON process show large sub-heap (about 4GB) called "kzaxins1-alloc" :

---> HEAP DUMP heap name="pga heap" desc=0xa9a3ee0
Type Count Sum Average
~~~~ ~~~~~ ~~~ ~~~~~~~
free 65417 303530920 4639.94
freeable 1177636 3981863144 3381.23
perm 27 236184 8747.56
recreate 5 15680 3136.00

BreakDown
~~~~~~~~~
Type Count Sum Average Percent
~~~~ ~~~~~ ~~~ ~~~~~~~ ~~~~~~~
Free(heap.awk) 65417 303530920 4639.94 7.08
KSXP connection 20 4800 240.00 0.00
kzaxLXRegMem 785034 47102072 60.00 1.10
kzaxins1-alloc 392517 3934590408 10024.00 91.81 <<<=== Problem allocation
.
.
.

Total = 4087.11MB


The PMON trace shows repeated errors like this:

kssxdl: error deleting SO: 0x9d6d2730 = session (4)
----------------------------------------
SO: 0x9d6d2730, type: 4, owner: 0x9e589260, flag: INIT/-/-/0x00 ...
proc=0x9e589260, name=session, file=ksu.h LINE:11467, pg=0
ORA-9817: Write to audit file failed.




Cause

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