Hi, nanyi607rao
 
  Can you show me the result of "show variables like 'slave_skip_errors';" ?
 
Best Regards,
dingqi
 

------------------------------------------------------------------发件人:nanyi607rao
 <[email protected]>发送时间:2013年7月16日(星期二) 15:20收件人:Jeremy Cole 
<[email protected]>抄 送:maria-developers 
<[email protected]>; Kristian Nielsen 
<[email protected]>; 丁奇 <[email protected]>主 题:Re: Re: 
[Maria-developers] The funcation of retry_transaction in parallen replication
hi Jeremy,
 
I can not give a test case because I have changed the way of retrying 
transaction in mysql-5.5.30 and then found this problem. The mysql-5.5.30 SQL 
thread's original way that retry failed events group(or a transaction) is 
droping the failed log-event object, then reading group's log events from BEGIN 
in relay log and applying their objects one by one again.for the log-event 
objects is new, the process of retry can get the same result as last time.
But in parallel replication of dingqi's patch the retry-way is changed. It 
reads in all events of a group and build a list of log-event objects in a time 
, then call log events' do_apply_event function from the event-object list head 
to tail. If there is some error happened, the retry-way is calling log events' 
do_apply_event function from the event-object list head again. so a log event 
object could do do_apply_event() twice. I imitated this process in 
mysql-5.5.30, made a log event object do do_apply_event() twice when it first 
time return nozero. then I find this problem that a 
Rows_log_event::do_apply_event() could call twice but return different 
results(first time is nozero, while second is zero). I also find the reason why 
the second time return zero is m_curr_row==m_rows_end in the Rows_log_event 
object. Does it need to set m_curr_row back to its original value before return 
from Rows_log_event::do_apply_event().
 
Regards,
 
Rao
 
 
2013-07-16

nanyi607rao

 

Hi,
 
Do you have a test case (or sequence of SQL statements you could provide in 
email)? Your email is a bit hard to follow, but this sounds interesting.
Regards,
 
Jeremy


On Thu, Jul 11, 2013 at 11:51 PM, nanyi607rao <[email protected]> wrote:


hi,
  In order to test  "retry_transaction" in function 
execute_single_transaction(), I change Relay_log_pos to make SQL thread insert 
Duplicate entry, but I find it successed and do not report error!
 
  so I debug the function execute_single_transaction() and find the reason : at 
first time, the insert Rows_log_event::do_apply_event() return 121, that means 
insert fails. But when retry the insert Rows_log_event::do_apply_event(),it 
return 0, that means insert success! it seems the 
Rows_log_event::do_apply_event() do twice, but return different results. how 
this happened? is it a bug of Rows_log_event::do_apply_event() ?
 
  By the way, I do this test in mysql-5.5.30, do mariaDB has the some problem?
 
 
2013-07-12

nanyi607rao

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