BUG#12400221 - 60926: BINARY LOG EVENTS LARGER THAN MAX_ALLOWED_PACKET

Problem
========
            
Replication breaks in the cases if the event length exceeds 
the size of master Dump thread's max_allowed_packet.
              
The reason why this failure is occuring is because the event length is
more than the total size of the max_allowed_packet, on addition of the  
max_event_header length exceeds the max_allowed_packet of the DUMP thread.
This causes the Dump thread to break replication and throw an error.
                      
That can happen e.g with row-based replication in Update_rows event.
            
Fix
====
          
The problem is fixed in 2 steps:

1.) The Dump thread limit to read event is increased to the upper limit
    i.e. Dump thread reads whatever gets logged in the binary log.

2.) On the slave side we increase the the max_allowed_packet for the
    slave's threads (IO/SQL) by increasing it to 1GB.

    This is done using the new server option (slave_max_allowed_packet)
    included, is used to regulate the max_allowed_packet of the  
    slave thread (IO/SQL) by the DBA, and facilitates the sending of
    large packets from the master to the slave.

    This causes the large packets to be received by the slave and apply
    it successfully.

sql/log_event.cc:
  The max_allowed_packet is not evaluated to the new option 
  slave_max_allowed_packet after the fix.
sql/log_event.h:
  Added the new option in the log_event.h file.
sql/mysqld.cc:
  Added a new option to the server.
sql/slave.cc:
  Increasing the session max_allowed_packet to a large value,
  i.e. not taking global(max_allowed) into consideration, for the slave's threads.
sql/sql_repl.cc:
  The dump thread's max_allowed_packet is set to the upper limit
  which makes it independent and it now reads whatever gets 
  logged in the binary log.

4 files changed, 14 insertions, 12 deletions

diff --git a/mysql-test/suite/rpl/r/rpl_log_pos.result b/mysql-test/suite/rpl/r/rpl_log_pos.result
index 91d307008f0..b2224dcd725 100644
--- a/mysql-test/suite/rpl/r/rpl_log_pos.result
+++ b/mysql-test/suite/rpl/r/rpl_log_pos.result
@@ -9,7 +9,7 @@ change master to master_log_pos=MASTER_LOG_POS;
 Read_Master_Log_Pos = '75'
 start slave;
 include/wait_for_slave_io_error.inc [errno=1236]
-Last_IO_Error = 'Got fatal error 1236 from master when reading data from binary log: 'log event entry exceeded max_allowed_packet; Increase max_allowed_packet on master''
+Last_IO_Error = 'Got fatal error 1236 from master when reading data from binary log: 'binlog truncated in the middle of event''
 include/stop_slave_sql.inc
 show master status;
 File	Position	Binlog_Do_DB	Binlog_Ignore_DB
diff --git a/mysql-test/suite/rpl/r/rpl_packet.result b/mysql-test/suite/rpl/r/rpl_packet.result
index 7a7f8141ac8..6d68a094594 100644
--- a/mysql-test/suite/rpl/r/rpl_packet.result
+++ b/mysql-test/suite/rpl/r/rpl_packet.result
@@ -1,7 +1,7 @@
 include/master-slave.inc
 [connection master]
-call mtr.add_suppression("Slave I/O: Got a packet bigger than 'max_allowed_packet' bytes, Error_code: 1153");
-call mtr.add_suppression("Slave I/O: Got fatal error 1236 from master when reading data from binary log:");
+call mtr.add_suppression("Slave I/O: Got a packet bigger than 'slave_max_allowed_packet' bytes, Error_code: 1153");
+call mtr.add_suppression("Log entry on master is longer than slave_max_allowed_packet");
 drop database if exists DB_NAME_OF_MAX_LENGTH_AKA_NAME_LEN_64_BYTES_____________________;
 create database DB_NAME_OF_MAX_LENGTH_AKA_NAME_LEN_64_BYTES_____________________;
 SET @@global.max_allowed_packet=1024;
@@ -30,14 +30,14 @@ include/start_slave.inc
 CREATE TABLE `t1` (`f1` LONGTEXT) ENGINE=MyISAM;
 INSERT INTO `t1`(`f1`) VALUES ('aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa2048');
 include/wait_for_slave_io_error.inc [errno=1153]
-Last_IO_Error = 'Got a packet bigger than 'max_allowed_packet' bytes'
+Last_IO_Error = 'Got a packet bigger than 'slave_max_allowed_packet' bytes'
 include/stop_slave_sql.inc
 include/rpl_reset.inc
 DROP TABLE t1;
 CREATE TABLE t1 (f1 int PRIMARY KEY, f2 LONGTEXT, f3 LONGTEXT) ENGINE=MyISAM;
 INSERT INTO t1(f1, f2, f3) VALUES(1, REPEAT('a', @@global.max_allowed_packet), REPEAT('b', @@global.max_allowed_packet));
-include/wait_for_slave_io_error.inc [errno=1236]
-Last_IO_Error = 'Got fatal error 1236 from master when reading data from binary log: 'log event entry exceeded max_allowed_packet; Increase max_allowed_packet on master''
+include/wait_for_slave_io_error.inc [errno=1153]
+Last_IO_Error = 'Got a packet bigger than 'slave_max_allowed_packet' bytes'
 STOP SLAVE;
 RESET SLAVE;
 RESET MASTER;
@@ -52,6 +52,7 @@ SET @@global.max_allowed_packet= 1024;
 Warnings:
 Warning	1105	The value of 'max_allowed_packet' should be no less than the value of 'net_buffer_length'
 SET @@global.net_buffer_length= 1024;
+SET @@global.slave_max_allowed_packet= 1073741824;
 DROP TABLE t1;
 RESET SLAVE;
 include/rpl_end.inc
diff --git a/mysql-test/suite/rpl/t/rpl_packet-slave.opt b/mysql-test/suite/rpl/t/rpl_packet-slave.opt
index 42d4f94c999..e0a7a203f99 100644
--- a/mysql-test/suite/rpl/t/rpl_packet-slave.opt
+++ b/mysql-test/suite/rpl/t/rpl_packet-slave.opt
@@ -1 +1 @@
--O max_allowed_packet=1024 -O net_buffer_length=1024
+-O max_allowed_packet=1024 -O net_buffer_length=1024 -O slave_max_allowed_packet=1024
diff --git a/mysql-test/suite/rpl/t/rpl_packet.test b/mysql-test/suite/rpl/t/rpl_packet.test
index 3197b6160cd..7fbea87f71e 100644
--- a/mysql-test/suite/rpl/t/rpl_packet.test
+++ b/mysql-test/suite/rpl/t/rpl_packet.test
@@ -11,9 +11,8 @@
 # max-out size db name 
 source include/master-slave.inc;
 source include/have_binlog_format_row.inc;
-call mtr.add_suppression("Slave I/O: Got a packet bigger than 'max_allowed_packet' bytes, Error_code: 1153");
-call mtr.add_suppression("Slave I/O: Got fatal error 1236 from master when reading data from binary log:");
-
+call mtr.add_suppression("Slave I/O: Got a packet bigger than 'slave_max_allowed_packet' bytes, Error_code: 1153");
+call mtr.add_suppression("Log entry on master is longer than slave_max_allowed_packet");
 let $db= DB_NAME_OF_MAX_LENGTH_AKA_NAME_LEN_64_BYTES_____________________;
 disable_warnings;
 eval drop database if exists $db;
@@ -23,6 +22,7 @@ eval create database $db;
 connection master;
 let $old_max_allowed_packet= `SELECT @@global.max_allowed_packet`;
 let $old_net_buffer_length= `SELECT @@global.net_buffer_length`;
+let $old_slave_max_allowed_packet= `SELECT @@global.slave_max_allowed_packet`;
 SET @@global.max_allowed_packet=1024;
 SET @@global.net_buffer_length=1024;
 
@@ -124,8 +124,8 @@ INSERT INTO t1(f1, f2, f3) VALUES(1, REPEAT('a', @@global.max_allowed_packet), R
 
 connection slave;
 # The slave I/O thread must stop after receiving
-# 1236=ER_MASTER_FATAL_ERROR_READING_BINLOG error message from master.
---let $slave_io_errno= 1236
+# 1153 = ER_NET_PACKET_TOO_LARGE
+--let $slave_io_errno= 1153
 --let $show_slave_io_error= 1
 --source include/wait_for_slave_io_error.inc
 
@@ -166,6 +166,7 @@ connection master;
 DROP TABLE t1;
 eval SET @@global.max_allowed_packet= $old_max_allowed_packet;
 eval SET @@global.net_buffer_length= $old_net_buffer_length;
+eval SET @@global.slave_max_allowed_packet= $old_slave_max_allowed_packet;
 # slave is stopped
 connection slave;
 DROP TABLE t1;