From: | Alvaro Herrera <alvherre(at)commandprompt(dot)com> |
---|---|
To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
Cc: | Nick <t32(at)2thebatcave(dot)com>, Kevin Grittner <kevin(dot)grittner(at)wicourts(dot)gov>, pgsql-admin <pgsql-admin(at)postgresql(dot)org> |
Subject: | Re: autovacuum launcher process eating up 17G+ of ram? |
Date: | 2010-11-08 15:01:51 |
Message-ID: | 1289227352-sup-6579@alvh.no-ip.org |
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Thread: | |
Lists: | pgsql-admin |
Excerpts from Tom Lane's message of lun oct 25 16:57:10 -0300 2010:
> It looks to me like the problem is that get_database_list()
> intentionally pushes its result into a long-lived context, and then the
> result is never cleaned up. It doesn't help any that it does a lot of
> leaky things like heap_beginscan with CurrentMemoryContext totally
> unnecessarily pointing at the long-lived context.
>
> I'm not sure what the intent was here, but it's pretty broken as-is.
> Alvaro, what did you have in mind? Should this be using a less
> long-lived context, or do we need code to free an avw_dbase list?
Sorry for not noticing this earlier. Seems my mail filters are broken
:-( Thanks Tom for the ping via private email.
Yes, get_database_list is clearly broken as is. I don't remember why
it's coded like this; this memcxt shuffling was introducing in the 9.0
rewrite to read pg_database directly instead of the flat file.
The right way for it to work seems to be to allocate the output list in
the caller's context; both current callers are in a throwaway context and
so the allocated list will go away automatically when they're done with
the list.
Patch for this is attached (applies cleanly to 9.0 and HEAD; 8.4 doesn't
need to be patched, but I'll run the test case now just to be sure.)
--
Álvaro Herrera <alvherre(at)commandprompt(dot)com>
The PostgreSQL Company - Command Prompt, Inc.
PostgreSQL Replication, Consulting, Custom Development, 24x7 support
Attachment | Content-Type | Size |
---|---|---|
0001-Fix-permanent-memory-leak-in-autovacuum-launcher.patch | application/octet-stream | 2.8 KB |
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