| Bug #54605 | Xid_log_event::do_apply_event() should update future_group_master_log_pos | ||
|---|---|---|---|
| Submitted: | 18 Jun 2010 6:22 | Modified: | 2 Nov 2010 21:16 |
| Reporter: | Yoshinori Matsunobu (OCA) | Email Updates: | |
| Status: | Won't fix | Impact on me: | |
| Category: | MySQL Server: Replication | Severity: | S3 (Non-critical) |
| Version: | 5.0, 5.1, 5.5 | OS: | Any |
| Assigned to: | Zhenxing He | CPU Architecture: | Any |
| Tags: | Contribution, replication | ||
[18 Jun 2010 8:06]
Sveta Smirnova
Thank you for the report. Which exact version of MySQL 5.1 do you use?
[18 Jun 2010 8:11]
Yoshinori Matsunobu
@Sveta, The latest (5.5.4, 5.1.47, and 5.0.91).
[22 Jun 2010 7:17]
Sveta Smirnova
Thank you for the feedback. Verified as described. Diff is for 5.5 series.
[28 Jun 2010 12:55]
Kristian Nielsen
I am wondering, what exactly is the bug here? It seems that future_group_master_log_pos is not actually used: $ find . -type f -print0|xargs -0 fgrep future_group_master_log_pos ./sql/log_event.cc: const_cast<Relay_log_info*>(rli)->future_group_master_log_pos= log_pos; ./sql/log_event.cc: const_cast<Relay_log_info*>(rli)->future_group_master_log_pos= log_pos; ./sql/log_event.cc: const_cast<Relay_log_info*>(rli)->future_group_master_log_pos= log_pos; ./sql/rpl_rli.h: ulonglong future_group_master_log_pos; It is assigned in a couple places, but never read (as far as I can determine). Maybe the real fix is to just remove this (old/unused/bogus?) code?
[2 Nov 2010 21:16]
Konstantin Osipov
Won't fix since this is 5.0 only.
[26 Nov 2012 15:20]
Florent Guiliani
As of 5.5.28 the 'problem' is still there. No one seems to make use of future_group_master_log_pos, even though the comment was mentioning InnoDB. I wonder what InnoDB does instead then? I am writing a storage engine and I would need it during the execution of a XID log event.
Description: Currently Xid_log_event::do_apply_event() (::exec_event() in 5.0) does not update rli->future_group_master_log_pos, but it should. Without updating future_group_master_log_pos here, InnoDB gets a position of *before* Xid event (generated by implicit/explicit commit), not *after* xid event. How to repeat: Read Xid_log_event::do_apply_event() in log_event.cc Suggested fix: int Xid_log_event::do_apply_event(Relay_log_info const *rli) { bool res; /* For a slave Xid_log_event is COMMIT */ general_log_print(thd, COM_QUERY, "COMMIT /* implicit, from Xid_log_event */"); + const_cast<Relay_log_info*>(rli)->future_group_master_log_pos= log_pos; if (!(res= trans_commit(thd))) { close_thread_tables(thd); thd->mdl_context.release_transactional_locks(); } return res; }