MySQL Bugs: #25835: Falcon: assertion on startup

Bug #25835	Falcon: assertion on startup
Submitted:	24 Jan 2007 17:14	Modified:	5 Feb 2007 15:52
Reporter:	Peter Gulutzan	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: Falcon storage engine	Severity:	S1 (Critical)
Version:	5.2.1-falcon-alpha-debug	OS:	Linux (SUSE 10.0 / 64-bit)
Assigned to:	Guilhem Bichot	CPU Architecture:	Any

Description:
I am using the latest Falcon, 'bk changes' says:
ChangeSet@1.2418.2.1, 2007-01-23 12:55:24-05:00 ...

Before trying to start mysqld, I deleted all files
on datadir, except what's in mysql database.

When I try to start mysqld, I get an assertion:
mysqld: log.cc:4457: virtual int TC_LOG_MMAP::open(const char*):
Assertion `opt_name && opt_name[0]' failed.

How to repeat:
Try to start mysqld.

Thank you for the bug report. Verified on Ubuntu 6.10 32-bit.

InnoDB: Creating foreign key constraint system tables
InnoDB: Foreign key constraint system tables created
070124 14:46:40  InnoDB: Started; log sequence number 0 0
mysqld: log.cc:4457: virtual int TC_LOG_MMAP::open(const char*): Assertion `opt_name && opt_name[0]' failed.
mysqld got signal 6;
This could be because you hit a bug. It is also possible that this binary

Crash also occurs with Ubuntu 32-bit.

Crash also occurs with BUILD/compile-pentium-max, i.e. non-debug version.

Since the crash is due to calling open(opt_bin_logname)
with opt_bin_log_name=0 from mysqld.cc, the workaround
is simple: always start mysqld with --log-bin=something.

Hi.
I suggest this patch. Please consider it. Contact me if want to discuss it.
[gbichot@production mysql-5.1-falcon]$ bk diffs -c sql
===== sql/log.cc 1.253 vs edited =====
*** /tmp/bk_log.cc-1.253_0xIoqm 2007-02-03 21:29:26 +01:00
--- edited/sql/log.cc   2007-02-03 21:24:02 +01:00
***************
*** 4537,4543 ****
        goto err;
      if (using_heuristic_recover())
        return 1;
!     if ((fd= my_create(logname, O_RDWR, 0, MYF(MY_WME))) < 0)
        goto err;
      inited=1;
      file_length= opt_tc_log_size;
--- 4537,4543 ----
        goto err;
      if (using_heuristic_recover())
        return 1;
!     if ((fd= my_create(logname, CREATE_MODE, O_RDWR, MYF(MY_WME))) < 0)
        goto err;
      inited=1;
      file_length= opt_tc_log_size;
===== sql/mysqld.cc 1.589 vs edited =====
*** /tmp/bk_mysqld.cc-1.589_ODQwsm      2007-02-03 21:29:26 +01:00
--- edited/sql/mysqld.cc        2007-02-03 21:21:45 +01:00
***************
*** 3317,3323 ****
                                 (TC_LOG *) &tc_log_mmap) :
             (TC_LOG *) &tc_log_dummy);

!   if (tc_log->open(opt_bin_logname))
    {
      sql_print_error("Can't init tc log");
      unireg_abort(1);
--- 3317,3323 ----
                                 (TC_LOG *) &tc_log_mmap) :
             (TC_LOG *) &tc_log_dummy);

!   if (tc_log->open(opt_bin_log ? opt_bin_logname : opt_tc_log_file))
    {
      sql_print_error("Can't init tc log");
      unireg_abort(1);

Notes:
1) even though not specified in the bug report, crash happens only if --log-bin (with or without argument) is not used; in this case, mysqld decides to use a mmap-based log instead of the binary log, to keep track of prepared transactions
2) but the problem was that this mmap-based log was created with the argument
of --log-bin as filename, which is wrong; it should use the --opt-tc-log-file option, which has a non-null default ("tc.log"), and which is meant for that
3) after fixing this, the mmap-based log was created, but unfortunately with wrong umask (due to some wrong argument in my_create()), thus when later mysqld wanted to modify/remove tc.log, it failed to do so.
Patch fixes those two issues. I get several successful start/shutdown of mysqld with it.

Hi Guilhem,

Thanks for looking at the issue and providing the patch! I will ask Sergei to conduct the review and PeterG/Matthias to write some XA test cases with both Falcon and InnoDB XA-enabled.

For the upcoming alpha release, the XA code for Falcon has been ifdefed out. We need to do more testing in this area (with your patch) and then make Falcon XA-enabled in a later alpha.

Thanks,
Calvin

Assign it to Guilhem, who agreed to push the patch into the Falcon tree on Monday. Thanks!

pushed in mysql-5.1-falcon.
https://intranet.mysql.com/secure/mailarchive/mail.php?folder=213&mail=3923
Crash was not possible with first alpha, so nothing to document