双主情况下跳过相同server id Event的方式：

IO线程 通过对比SERVER_ID 进行跳过操作

{mi->set_master_log_pos(mi->get_master_log_pos()+inc_pos);memcpy(rli->ign_master_log_name_end,mi->get_master_log_name(),FN_REFLEN);DBUG_ASSERT(rli->ign_master_log_name_end[0]);rli->ign_master_log_pos_end=mi->get_master_log_pos();}

SQL线程构造一个Rotate_log_event

if(rli->ign_master_log_name_end[0]){/*WegenerateandreturnaRotate,tomakeourpositionsadvance*/DBUG_PRINT("info",("seeinganignoredendsegment"));ev=newRotate_log_event(rli->ign_master_log_name_end,0,rli->ign_master_log_pos_end,exec_relay_log_eventRotate_log_event::DUP_NAME);rli->ign_master_log_name_end[0]=0;mysql_mutex_unlock(log_lock);exec_relay_log_eventif(unlikely(!ev)){errmsg="SlaveSQLthreadfailedtocreateaRotateevent""(outofmemory?),SHOWSLAVESTATUSmaybeinaccurate";gotoerr;}ev->server_id=0;//don'tbeignoredbyslaveSQLthreadDBUG_RETURN(ev);}

这样这些Event不会写入到relay log，SQL线程也不会读取，同时pos 也会做相应的增加。