From: Eric Bergen
Date: November 7 2007 9:37pm
Subject: Re: Changing lock output in InnoDB status (bug #29126)
List-Archive: http://lists.mysql.com/internals/35160
Message-Id: <28fd48f00711071337r6b19c80aq3140748b7a989d00@mail.gmail.com>
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I would rather see verbosity options be something that can be changed
at runtime instead of compile time.

On 11/6/07, Baron Schwartz <baron@stripped> wrote:
> One of my feature requests for InnoDB
> (http://bugs.mysql.com/bug.php?id=29126) is to disable the verbose lock
> output in SHOW INNODB STATUS.  It looks to me like it can be done very
> easily in innobase/lock/lock0lock.c by changing this code:
>
> 4172    for (i = 0; i < lock_rec_get_n_bits(lock); i++) {
> 4173
> 4174       if (lock_rec_get_nth_bit(lock, i)) {
> 4175
> 4176          fprintf(file, "Record lock, heap no %lu ", (ulong) i);
> 4177
> 4178          if (page) {
> 4179             rec_t*   rec
> 4180                = page_find_rec_with_heap_no(page, i);
> 4181             offsets = rec_get_offsets(rec, lock->index,
> 4182                offsets, ULINT_UNDEFINED, &heap);
> 4183             rec_print_new(file, rec, offsets);
> 4184          }
> 4185
> 4186          putc('\n', file);
> 4187       }
> 4188    }
>
> I could easily comment that out, but it'd be nice to make a patch others
> could use.  I think all I need to do is add a #ifdef around that.  But
> what should I #ifdef with?  I see UNIV_SYNC_DEBUG in lots of places in
> the source, but maybe there's something better.
>
> The other part of that feature request is to always print the locks for
> each transaction, as is done when the innodb_lock_monitor is enabled.
> This way I can see locks held, without filling the error log with them.
>   I think the best way to do that is to add a server variable that will
> allow that to be configurable, but I doubt that's as easy as the
> following patch against the 5.0.45 source, which accomplishes both of my
> desired changes, plus changes the number of locks printed from 10 to 50:
>
> baron@tigger mysql-5.0.45 $ diff -ur innobase/lock/lock0lock.c{.orig,}
> --- innobase/lock/lock0lock.c.orig      2007-11-06 16:50:26.000000000 -0500
> +++ innobase/lock/lock0lock.c   2007-11-06 17:07:23.000000000 -0500
> @@ -4169,6 +4169,7 @@
>   #endif /* UNIV_SYNC_DEBUG */
>          }
>
> +#ifdef UNIV_SYNC_DEBUG
>          for (i = 0; i < lock_rec_get_n_bits(lock); i++) {
>
>                  if (lock_rec_get_nth_bit(lock, i)) {
> @@ -4186,6 +4187,7 @@
>                          putc('\n', file);
>                  }
>          }
> +#endif /* UNIV_SYNC_DEBUG */
>
>          mtr_commit(&mtr);
>          if (UNIV_LIKELY_NULL(heap)) {
> @@ -4357,11 +4359,6 @@
>                  }
>          }
>
> -       if (!srv_print_innodb_lock_monitor) {
> -               nth_trx++;
> -               goto loop;
> -       }
> -
>          i = 0;
>
>          /* Look at the note about the trx loop above why we loop here:
> @@ -4414,9 +4411,9 @@
>
>          nth_lock++;
>
> -       if (nth_lock >= 10) {
> +       if (nth_lock >= 50) {
>                  fputs(
> -               "10 LOCKS PRINTED FOR THIS TRX: SUPPRESSING FURTHER
> PRINTS\n",
> +               "50 LOCKS PRINTED FOR THIS TRX: SUPPRESSING FURTHER
> PRINTS\n",
>                          file);
>
>                  nth_trx++;
>
>
> Advice is appreciated.  I'll do this one way or another, as I really
> need to see the locks and not the locked records for day-to-day
> troubleshooting and admin jobs.  But doing it "the right way" would be
> nice :-)
>
> Thanks
> Baron
>
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>


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