ORA-4031 or ORA-4030 With Memory Leak In 'koh dur heap d' (Doc ID 850219.1)

Last updated on NOVEMBER 28, 2016

Applies to:

Oracle Server - Enterprise Edition - Version: 10.2.0.4 and later   [Release: 10.2 and later ]
Information in this document applies to any platform.

Symptoms

This issue was observed on a Linux 64-bit server with 10.2.0.4

Symptoms:

- ORA-4031 reported on the Large pool.

- The alert log may show errors similar to this:
   ORA-04031: unable to allocate 24600 bytes of shared memory ("large pool","unknown object","koh-kghu sessi","static frame of inst").

- Increasing the large pool, only delays the return of the ORA-4031.

- This leak can also be seen as ORA-4030

To debug this issue more, we need to get a heapdump and reproduce the 4031.
SQL> ALTER SYSTEM SET EVENTS '4031 trace name heapdump level 536870944

- The heapdump will show the leak is in heap 'koh dur heap d' with memory tagged as 'kolaGetRfcHeap'

- A search of the trace file will show that XDB functions are being used.

- The function stack usually shows a LOB was being used:

kghalp
kghsupmm
kghssgmm
kghssagptr 
kolasaWrite
kolaslWrite
kolaWrite
koklwrite
koklc_write
koleswrite
kghscbcwall
kghscbcwrite2
kghsccwrite
kghsos_write
qmudx_LobCopy2

 


Cause

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