hi,
If character_set in different Query_log_events changed, worker threads may
apply them with wrong character_set. the codes leading this problem is in
Query_log_event::do_apply_event, that is:
if (charset_inited)
{
if (rli->cached_charset_compare(charset))
{
/* Verify that we support the charsets found in the event. */
if (!(thd->variables.character_set_client=
get_charset(uint2korr(charset), MYF(MY_WME))) ||
!(thd->variables.collation_connection=
get_charset(uint2korr(charset+2), MYF(MY_WME))) ||
!(thd->variables.collation_server=
get_charset(uint2korr(charset+4), MYF(MY_WME))))
{
There is a charset[6] in rli, which cached last Query_log_event's charset in
serial replication. But in parallel replication it would lead mistake, because
every worker thread can read and set rli->charset[6], so rli->charset[6] isn't
any worker threads' last Query_log_event charset. but rli->charset[6] can
affect every worker threads' thd->variables.character_set_* setting.
2014-04-17
nanyi607rao
_______________________________________________
Mailing list: https://launchpad.net/~maria-developers
Post to : maria-developers@lists.launchpad.net
Unsubscribe : https://launchpad.net/~maria-developers
More help : https://help.launchpad.net/ListHelp
