List:Commits« Previous MessageNext Message »
From:Luis Soares Date:March 16 2011 4:03pm
Subject:bzr push into mysql-5.1 branch (luis.soares:3616 to 3617) Bug#59717
Bug#11868903
View as plain text  
 3617 Luis Soares	2011-03-16
      Fix for BUG#11868903 (BUG#59717)
            
      There is a race between two threads: user thread and the dump
      thread. The former sets a debug instruction that makes the latter wait
      before processing an Xid event. There can be cases that the dump
      thread has not yet processed the previous Xid event, causing it to
      wait one Xid event too soon, thus causing sync_slave_with_master never
      to resume.
            
      We fix this by moving the instructions that set the debug variable
      after calling sync_slave_with_master.

    modified:
      mysql-test/suite/rpl/r/rpl_stop_slave.result
      mysql-test/suite/rpl/t/rpl_stop_slave.test
 3616 Dmitry Shulga	2011-03-15
      Fixed Bug#11764168 "56976: SEVERE DENIAL OF SERVICE IN PREPARED STATEMENTS".
      
      The problem was that server didn't check resulting size of prepared
      statement argument which was set using mysql_send_long_data() API.
      By calling mysql_send_long_data() several times it was possible
      to create overly big string and thus force server to allocate
      memory for it. There was no way to limit this allocation.
      
      The solution is to add check for size of result string against
      value of max_long_data_size start-up parameter. When intermediate
      string exceeds max_long_data_size value an appropriate error message
      is emitted.
      
      We can't use existing max_allowed_packet parameter for this purpose
      since its value is limited by 1GB and therefore using it as a limit
      for data set through mysql_send_long_data() API would have been an
      incompatible change. Newly introduced max_long_data_size parameter
      gets value from max_allowed_packet parameter unless its value is
      specified explicitly. This new parameter is marked as deprecated
      and will be eventually replaced by max_allowed_packet parameter.
      Value of max_long_data_size parameter can be set only at server
      startup.
     @ mysql-test/t/variables.test
        Added checking for new start-up parameter max_long_data_size.
     @ sql/item.cc
        Added call to my_message() when accumulated string exceeds
        max_long_data_size value. my_message() calls error handler
        that was installed in mysql_stmt_get_longdata before call
        to Item_param::set_longdata.
        
        The error handler then sets state, last_error and last_errno
        fields for current statement to values which correspond to
        error which was caught.
     @ sql/mysql_priv.h
        Added max_long_data_size variable declaration.
     @ sql/mysqld.cc
        Added support for start-up parameter 'max_long_data_size'.
        This parameter limits size of data which can be sent from
        client to server using mysql_send_long_data() API.
     @ sql/set_var.cc
        Added variable 'max_long_data_size' into list of variables
        displayed by command 'show variables'.
     @ sql/sql_prepare.cc
        Added error handler class Set_longdata_error_handler.
        This handler is used to catch any errors that can be
        generated during execution of Item_param::set_longdata().
        
        Source code snippet that makes checking for statement's state 
        during statement execution is moved from Prepared_statement::execute()
        to Prepared_statement::execute_loop() in order not to call
        set_parameters() when statement has failed during
        set_long_data() execution. If this hadn't been done
        the call to set_parameters() would have failed.
     @ tests/mysql_client_test.c
        A testcase for the bug #56976 was added.

    modified:
      mysql-test/r/variables.result
      mysql-test/t/variables.test
      sql/item.cc
      sql/mysql_priv.h
      sql/mysqld.cc
      sql/set_var.cc
      sql/sql_prepare.cc
      tests/mysql_client_test.c
=== modified file 'mysql-test/suite/rpl/r/rpl_stop_slave.result'
--- a/mysql-test/suite/rpl/r/rpl_stop_slave.result	2011-01-18 17:23:49 +0000
+++ b/mysql-test/suite/rpl/r/rpl_stop_slave.result	2011-03-16 15:11:54 +0000
@@ -146,6 +146,7 @@ DROP TABLE t1, t2;
 CREATE TABLE t1 (c1 INT KEY, c2 INT) ENGINE=InnoDB;
 CREATE TABLE t2 (c1 INT) ENGINE=MyISAM;
 INSERT INTO t1 VALUES(1, 1);
+[connection master]
 SET GLOBAL debug= 'd,dump_thread_wait_before_send_xid';
 [connection slave]
 include/restart_slave.inc

=== modified file 'mysql-test/suite/rpl/t/rpl_stop_slave.test'
--- a/mysql-test/suite/rpl/t/rpl_stop_slave.test	2011-01-18 17:23:49 +0000
+++ b/mysql-test/suite/rpl/t/rpl_stop_slave.test	2011-03-16 15:11:54 +0000
@@ -76,11 +76,13 @@ CREATE TABLE t1 (c1 INT KEY, c2 INT) ENG
 CREATE TABLE t2 (c1 INT) ENGINE=MyISAM;
 INSERT INTO t1 VALUES(1, 1);
 
+sync_slave_with_master;
+
+--source include/rpl_connection_master.inc
+
 let $debug_save= `SELECT @@GLOBAL.debug`;
 SET GLOBAL debug= 'd,dump_thread_wait_before_send_xid';
 
-sync_slave_with_master;
-
 --source include/rpl_connection_slave.inc
 source include/restart_slave_sql.inc;
 

No bundle (reason: useless for push emails).
Thread
bzr push into mysql-5.1 branch (luis.soares:3616 to 3617) Bug#59717Bug#11868903Luis Soares16 Mar