Re: BUG #14180: Segmentation fault on replication slave

> On 2016-06-07 19:41, Andres Freund wrote:
> > > > Program received signal SIGSEGV, Segmentation fault.
> > > > _bt_restore_page (page=0x7f816fce2b40 "", from=0x55a0945abb70
> > > > "\036", len=<optimized out>) at
> > > > /build/postgresql-9.5-xp9utH/postgresql-9.5-
> > > 9.5.3/build/../src/backend/access/nbtree/nbtxlog.c:57
> > > > 57
> > > > /build/postgresql-9.5-xp9utH/postgresql-9.5-
> > > 9.5.3/build/../src/backend/access/nbtree/nbtxlog.c:
> > > > No such file or directory.
> > > > (gdb) bt
> > > > #0 _bt_restore_page (page=0x7f816fce2b40 "", from=0x55a0945abb70
> > > > "\036", len=<optimized out>) at
> > > > /build/postgresql-9.5-xp9utH/postgresql-9.5-9.5.3/build/../src/bac
> > > > kend
> > > > /access/nbtree/nbtxlog.c:57
> > > > #1 0x0000000000000000 in ?? ()
> > > > (gdb) p from
> > > > $1 = 0x55a0945abb70 "\036"
> > > > (gdb) p end
> > > > $2 = 0x55a0945ac928 "\305cO"
> > > > (gdb) p i
> > > > $3 = 3324
> > > > (gdb) p len
> > > > $4 = <optimized out>
> > > > (gdb) p &itupdata
> > > > $5 = (IndexTupleData *) 0x7ffe83ea84e0
> > > > (gdb) p items
> > > > $6 = {0x0 <repeats 408 times>}
> > > > (gdb) p &items
> > > > $7 = (Item (*)[408]) 0x7ffe83ea8820
> > > > (gdb) p itemsz
> > > > $8 = <optimized out>
> > >
> > > Uhm, this is a bit odd. There's no backtrace, but types and such are
> > > known? I guess you do have the debug symbols installed?
> >
> > Yeah, it's confusing. I installed the result of ./list-dbgsym-packages-v2.1.sh -
> p $pid which gave:
> >
> > libcomerr2-dbg libffi6-dbg libgcc1-dbg libicu55-dbg libldap-2.4-2-dbg
> > libsqlite3-0-dbg libssl1.0.0-dbg libxml2-dbg postgresql-9.5-dbg
> > zlib1g-dbg
> >
> > Not sure what else I can do short of recompiling postgresql mysql.
>
> Any chance the running version of postgres is out of date with the installed
> binaries / debug symbols?

You mean that I upgraded without restarting postgres before the segfault?

Before this I have had the same problem with Ubuntu 14.04 with postgresql 9.5.3 from a ppa. I then tried building a new VM based on Ubuntu 16.04 on the 3rd of June to see if there was something wrong with the slave VM. So it's a clean install where I installed latest postgresql once and ran it. I've reproduced the problem three times since that happened with one reboot in between. Of course what hasn't changed during all of this is the master.

The version of postgresql-client-9.5, libpq5, postgreql-9.5, postgresql-contrib-9.5 and postgresql-9.5-dbg are all at 9.5.3-0ubuntu0.16.04.

Regards,
Bo Ørsted Andresen