maria-developers team mailing list archive

[kentoku <kentokushiba@xxxxxxxxx>]

Hi Sergey,

> The above should have been fixed back in the beginning of 2012. Which
MariaDB
revision are you testing with?
It's same as lp:~kentokushiba/maria/10.0.4-spider-3.0.
By the way, I found a problem point in Spider. Currently it is fixed and
pushed. And I can't reproduce assertion failure. Can you reproduce this
failure yet?

Thanks,
Kentoku




2013/9/24 Sergey Vojtovich <svoj@xxxxxxxxxxx>

> Hi Kentoku,
>
> On Thu, Sep 19, 2013 at 11:47:33PM +0900, kentoku wrote:
> > Hi Sergey,
> >
> > > I'm afraid fixing rnd_end() callers in the server may stall for a long
> > time.
> > O.K. No need to fix it if it is not easy. This request is not high
> priority
> > request.
> >
> > > Is it accaptable for spider to use bulk updates and deletes API instead
> > > (see handler.h: start_bulk_update/start_bulk_delete).
> > Spider use it already. This API is not used if target table has after
> > trigger. I understand why this API is not used in this case, but it
> > sometimes causes performance problem. So, I thought it is better to
> prepare
> > other choice for something wrong. Anyway, I will disable bulk
> > updating/deleting feature without using API.
> I see. Hope it is acceptable.
>
> >
> > > Nope, it looks like a bug in thread pool. MDEV-4739 has different
> trace,
> > how
> > did you get this one? Just executed given test?
> > I got this trace when I try to reproduce MDEV-4739. I did as the
> followings.
> >
> > 1. start mysqld
> > 2. log in mysqld
> > 3. mysql> CREATE TABLE t1 (a INT) ENGINE=InnoDB;
> > 4. mysql> XA START 'xa1';
> > 5. mysql> INSERT INTO t1 (a) VALUES (1),(2);
> > 6. mysql> XA END 'xa1';
> > 7. mysql> XA PREPARE 'xa1';
> > 8. kill -9 mysqld_safe and mysqld from another terminal
> > 9. start mysqld on gdb
> >
> > At that time, InnoDB and Spider were enabled and log-bin was disabled. So
> > probably "total_ha_2pc > 1" was true, "opt_bin_log" was false.
> > Does it help you?
> We couldn't reproduce it yet. :(
>
> Looking through the code I noticed that call to thd_wait_begin() looks as
> following:
>
> static void scheduler_wait_sync_begin(void) {
>   thd_wait_begin(NULL, THD_WAIT_SYNC);
> }
>
> Note that thd is always NULL. And it must be NULL at this point, because
> we're
> booting. But according to your trace thd is not NULL.
>
> #0  0x00000000005eabf6 in thd_wait_begin (
>     thd=0x29da060, wait_type=10)
>     at /ssd1/mariadb-10.0.4/sql/sql_class.cc:4277
> #1  0x000000000072a114 in scheduler_wait_sync_begin ()
>     at /ssd1/mariadb-10.0.4/sql/scheduler.cc:59
> ...
>
> The above should have been fixed back in the beginning of 2012. Which
> MariaDB
> revision are you testing with?
>
> Thanks,
> Sergey
>
>
>
> >
> > Thanks,
> > Kentoku
> >
> >
> >
> > 2013/9/19 Sergey Vojtovich <svoj@xxxxxxxxxxx>
> >
> > > Hi Kentoku,
> > >
> > > I'm adding MariaDB developers to CC.
> > >
> > > On Thu, Sep 19, 2013 at 01:19:13AM +0900, kentoku wrote:
> > > > Hi Sergey,
> > > >
> > > > > But what kind of errors are possible in your case? Other storage
> > > engines
> > > > doesn't
> > > > seem to suffer from this API violation.
> > > >
> > > > Spider support bulk updating and deleting for avoiding network
> roundtrip
> > > > between data node. Some times, last bulk updating is executed in
> > > rnd_end()
> > > > function. So rnd_end() has possibility getting errors from data node.
> > > I'm afraid fixing rnd_end() callers in the server may stall for a long
> > > time.
> > > Is it accaptable for spider to use bulk updates and deletes API instead
> > > (see handler.h: start_bulk_update/start_bulk_delete).
> > >
> > > > By the way, about MDEV-4739. I get the following stack trace.
> > > > Program received signal SIGSEGV, Segmentation fault.
> > > > 0x00000000005eabf6 in thd_wait_begin (thd=0x29da060,
> > > >     wait_type=10)
> > > >     at /ssd1/mariadb-10.0.4/sql/sql_class.cc:4277
> > > > 4277      MYSQL_CALLBACK(thd->scheduler, thd_wait_begin, (thd,
> > > wait_type));
> > > > (gdb) print thd
> > > > $1 = (THD *) 0x29da060
> > > > (gdb) bt
> > > > #0  0x00000000005eabf6 in thd_wait_begin (
> > > >     thd=0x29da060, wait_type=10)
> > > >     at /ssd1/mariadb-10.0.4/sql/sql_class.cc:4277
> > > > #1  0x000000000072a114 in scheduler_wait_sync_begin ()
> > > >     at /ssd1/mariadb-10.0.4/sql/scheduler.cc:59
> > > > #2  0x0000000000d6dc20 in my_sync (fd=23, my_flags=0)
> > > >     at /ssd1/mariadb-10.0.4/mysys/my_sync.c:76
> > > > #3  0x0000000000d6b54f in my_msync (fd=23,
> > > >     addr=0x7ffff7ff4000, len=4096, flags=4)
> > > >     at /ssd1/mariadb-10.0.4/mysys/my_mmap.c:27
> > > > #4  0x00000000008bea03 in TC_LOG_MMAP::open (
> > > >     this=0x16e6a00, opt_name=0xe19c87 "tc.log")
> > > >     at /ssd1/mariadb-10.0.4/sql/log.cc:7735
> > > > #5  0x00000000005751cb in init_server_components ()
> > > >     at /ssd1/mariadb-10.0.4/sql/mysqld.cc:4797
> > > > #6  0x0000000000575a07 in mysqld_main (argc=30,
> > > >     argv=0x1f204d0)
> > > >     at /ssd1/mariadb-10.0.4/sql/mysqld.cc:5208
> > > > #7  0x000000000056d884 in main (argc=11,
> > > >     argv=0x7fffffffe3a8)
> > > >     at /ssd1/mariadb-10.0.4/sql/main.cc:25
> > > > (gdb) print thd->scheduler
> > > > $2 = (scheduler_functions *) 0x8f8f8f8f8f8f8f8f
> > > > (gdb) print thd_wait_begin
> > > > $3 = {void (THD *,
> > > >     int)} 0x5eaba4 <thd_wait_begin(THD*, int)>
> > > > (gdb) print wait_type
> > > > $4 = 10
> > > >
> > > > It is looks that "thd->scheduler" is not initialized. What do you
> think?
> > > > Must storage engine set it?
> > > Nope, it looks like a bug in thread pool. MDEV-4739 has different
> trace,
> > > how
> > > did you get this one? Just executed given test?
> > >
> > > Regards,
> > > Sergey
> > >
>