Commit ce858166 authored by unknown's avatar unknown
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Try to lower the probability of a stall of mysqldump AND most client... 

Try to lower the probability of a stall of mysqldump AND most client connections, when mysqldump does a FLUSH TABLES WITH READ LOCK
(doing FLUSH TABLES first).


client/mysqldump.c:
  try to lower the probability of a stall of mysqldump AND most client connections, when mysqldump does a FLUSH TABLES WITH READ LOCK
  (doing FLUSH TABLES first).
parent d6f7134d

client/mysqldump.c

+11 −1
Original line number Diff line number Diff line
@@ -2050,8 +2050,18 @@ static int do_show_master_status(MYSQL *mysql_con) 


static int do_flush_tables_read_lock(MYSQL *mysql_con)

{

  /*

    We do first a FLUSH TABLES. If a long update is running, the FLUSH TABLES

    will wait but will not stall the whole mysqld, and when the long update is

    done the FLUSH TABLES WITH READ LOCK will start and succeed quickly. So,

    FLUSH TABLES is to lower the probability of a stage where both mysqldump

    and most client connections are stalled. Of course, if a second long

    update starts between the two FLUSHes, we have that bad stall.

  */

  return 

    mysql_query_with_error_report(mysql_con, 0, "FLUSH TABLES WITH READ LOCK");

    ( mysql_query_with_error_report(mysql_con, 0, "FLUSH TABLES") ||

      mysql_query_with_error_report(mysql_con, 0,

                                    "FLUSH TABLES WITH READ LOCK") );

}