Re: Out of Memory errors are frustrating as heck! - Mailing list pgsql-performance

From Jeff Janes
Subject Re: Out of Memory errors are frustrating as heck!
Date
Msg-id CAMkU=1wNtOsh1+mbTuR=O+Qk1aUXNN6Z0jabY-RX12Ay=CZZ5g@mail.gmail.com
Whole thread Raw
In response to Re: Out of Memory errors are frustrating as heck!  (Gunther <raj@gusw.net>)
List pgsql-performance
On Mon, Apr 15, 2019 at 12:34 PM Gunther <raj@gusw.net> wrote:
Breakpoint 2, AllocSetAlloc (context=0x1168230, size=8272) at aset.c:715
715     {
(gdb) p context->name
$8 = 0x96ce5b "ExecutorState"


I think that the above one might have been the one you wanted.
 

I guess I should run this for a little longer. So I disable my breakpoints 

it went up pretty quick from 1.2 GB to 1.5 GB, but then it stopped growing fast, so now back to gdb and break:

Unfortunately, I think this means you missed your opportunity and are now getting backtraces of the innocent bystanders.

Particularly since you report that the version using nested loops rather than hash joins also leaked, so it is probably not the hash-join specific code that is doing it.

What I've done before is compile with the comments removed from 
src/backend/utils/mmgr/aset.c:/* #define HAVE_ALLOCINFO */ 

and then look for allocations sizes which are getting allocated but not freed, and then you can go back to gdb to look for allocations of those specific sizes.  This generates a massive amount of output, and it bypasses the logging configuration and goes directly to stderr--so it might not end up where you expect.


Thanks for the view definition.  Nothing in it stood out to me as risky.

Cheers,

Jeff

pgsql-performance by date:

Previous
From: Tom Lane
Date:
Subject: Re: Out of Memory errors are frustrating as heck!
Next
From: Gunther
Date:
Subject: Re: Out of Memory errors are frustrating as heck!