Re: BUG #11264: Auto vacuum wraparound job blocking everything

Alvaro Herrera wrote:

> > (gdb) bt
> > #0  0x00007fb9740eb5b3 in __select_nocancel () from /lib64/libc.so.6
> > #1  0x000000000075ad7a in pg_usleep ()
> > #2  0x00000000004ae2d4 in GetMultiXactIdMembers ()
> > #3  0x000000000047f6cc in heap_prepare_freeze_tuple ()
> > #4  0x000000000057d036 in lazy_vacuum_rel ()
>
> This stall in GetMultiXactIdMembers should only occur when somebody is
> writing the multixact immediately following.  It certainly should not
> sleep for long.  I'm not sure what's happening here but this is probably
> where the problem is.  While waiting, it holds the buffer content lock
> in exclusive mode.
>
> Can you install debug symbols and pageinspect?

If you have debug symbols, please attach to this process, then do in
GDB:
  bt full

--
Álvaro Herrera                http://www.2ndQuadrant.com/
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