Re: Scaling XLog insertion (was Re: Moving more work outside WALInsertLock)

On 15.02.2012 18:52, Fujii Masao wrote:
> On Thu, Feb 16, 2012 at 1:01 AM, Heikki Linnakangas
> <heikki(dot)linnakangas(at)enterprisedb(dot)com> wrote:
>> Are you still seeing this failure with the latest patch I posted
>> (http://archives.postgresql.org/message-id/4F38F5E5.8050203@enterprisedb.com)?
>
> Yes. Just to be safe, I again applied the latest patch to HEAD,
> compiled that and tried
> the same test. Then unfortunately I got the same failure again.

Ok.

> I ran the configure with '--enable-debug' '--enable-cassert'
> 'CPPFLAGS=-DWAL_DEBUG',
> and make with -j 2 option.
>
> When I ran the test with wal_debug = on, I got the following assertion failure.
>
> LOG: INSERT @ 0/17B3F90: prev 0/17B3F10; xid 998; len 31: Heap -
> insert: rel 1663/12277/16384; tid 0/197
> STATEMENT: create table t (i int); insert into t
> values(generate_series(1,10000)); delete from t
> LOG: INSERT @ 0/17B3FD0: prev 0/17B3F50; xid 998; len 31: Heap -
> insert: rel 1663/12277/16384; tid 0/198
> STATEMENT: create table t (i int); insert into t
> values(generate_series(1,10000)); delete from t
> TRAP: FailedAssertion("!(((bool) (((void*)(&(target->tid)) != ((void
> *)0))&& ((&(target->tid))->ip_posid != 0))))", File: "heapam.c",
> Line: 5578)
> LOG: xlog bg flush request 0/17B4000; write 0/17A6000; flush 0/179D5C0
> LOG: xlog bg flush request 0/17B4000; write 0/17B0000; flush 0/17B0000
> LOG: server process (PID 16806) was terminated by signal 6: Abort trap
>
> This might be related to the original problem which Jeff and I saw.

That's strange. I made a fresh checkout, too, and applied the patch, but
still can't reproduce. I used the attached script to test it.

It's surprising that the crash happens when the records are inserted,
not at recovery. I don't see anything obviously wrong there, so could
you please take a look around in gdb and see if you can get a clue
what's going on? What's the stack trace?

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com