Home » RDBMS Server » Server Administration » Out of Memory - Runaway Memory, not releasing ORA-04036: PGA memory used by the instance exceeds (12c Release 2, Linux 7, Peoplesoft Tool 8.56)
Out of Memory - Runaway Memory, not releasing ORA-04036: PGA memory used by the instance exceeds [message #678257] Wed, 20 November 2019 17:46 Go to next message
oraclefan12345
Messages: 1
Registered: November 2019
Junior Member
We set PGA_AGGREGATE_LIMIT to 2 up to 6 when running data warehouse extraction on 2 databases(Peoplesoft); however, we still went over the limit and used up all swap space. This crashed both databases on server, pretty bad. We received ORA-04036: PGA memory used by the instance exceeds.
We open a ticket with Oracle and they had us set the limit to 0 but still max out on memory and crashed server and DBS.

I am thinking this must bugs on release 2.

Oracle mentioned that max_map_count should be at least 200000 but our is 65530.

Anyone ran into runaway memory issues? It could be either Oracle bugs, or server configuration.

Interesting same processes ran fine on 12c R1 on the same server so it must be something on Release 2.






From Oracle Support.

1) check current map count value.
eg: more /proc/sys/vm/max_map_count

2) if its lower than 200000, raise it:

vm.max_map_count - should at least be 200000 .
  1. sysctl -w vm.max_map_count=200000
Our server has 65530. Should we increase to at least 200000?

clbdev790::/tmp $ more /proc/sys/vm/max_map_count
65530

From google


From the Linux kernel documentation: max_map_count: This file contains the maximum number of memory map areas a process may have. Memory map areas are used as a side-effect of calling malloc, directly by mmap and mprotect, and also when loading shared libraries.Nov 11, 2017

Re: Out of Memory - Runaway Memory, not releasing ORA-04036: PGA memory used by the instance exceeds [message #678258 is a reply to message #678257] Wed, 20 November 2019 20:41 Go to previous messageGo to next message
BlackSwan
Messages: 26640
Registered: January 2009
Location: SoCal
Senior Member
Welcome to this forum

Please read and follow the forum guidelines, to enable us to help you:
OraFAQ Forum Guide
How to use {code} tags and make your code easier to read

https://docs.oracle.com/database/121/ADMIN/memory.htm#ADMIN11233
Re: Out of Memory - Runaway Memory, not releasing ORA-04036: PGA memory used by the instance exceeds [message #678260 is a reply to message #678257] Thu, 21 November 2019 02:18 Go to previous message
John Watson
Messages: 8076
Registered: January 2010
Location: Global Village
Senior Member
Why would you not do as you have been advised: adjust max_map_count ?

Apart from that, I would consider tuning the code in this "extraction" process so that it needs less PGA.
Previous Topic: Location of alert log file
Goto Forum:
  


Current Time: Mon Dec 09 09:56:46 CST 2019