Generalized support for auto-updated and/or auto-initialized timestamp
and datetime columns. This patch is a reimplementation of MySQL's
"WL#5874: CURRENT_TIMESTAMP as DEFAULT for DATETIME columns". In order to
ease future merges, this implementation reused few function and variable
names from MySQL's patch, however the implementation is quite different.
TODO:
The only unresolved problem in this patch is the semantics of LOAD DATA for
TIMESTAMP and DATETIME columns in the cases when there are missing or NULL
columns. I couldn't fully comprehend the logic behind MySQL's behavior and
its relationship with their own documentation, so I left the results to be
more consistent with all other LOAD cases.
The problematic test cases can be seen by running the test file function_defaults,
and observing the test case differences. Those were left on purpose for discussion.
This bug had two problems:
P1) Reads out of bounds;
P2) Writes out of bounds.
PROBLEM P1
----------
User_var_log_event unmarshalling from binlog was not performing range
checks when using name_len and val_len variables to walk on event
buffer.
Added range checks to User_var_log_event unmarshalling to prevent
unmarshalling errors.
PROBLEM P2
----------
User_var_log_event value was allocated on thread stack, what caused
stack frame errors when User_var_log_event value was bigger than thread
stack size.
Currently value is allocated on heap memory.
CONSISTENT SNAPSHOT OPTION
A transaction is started with a consistent snapshot. After
the transaction is started new indexes are added to the
table. Now when we issue an update statement, the optimizer
chooses an index. When the index scan is being initialized
via ha_innobase::change_active_index(), InnoDB reports
the error code HA_ERR_TABLE_DEF_CHANGED, with message
stating that "insufficient history for index".
This error message is propagated up to the SQL layer. But
the my_error() api is never called. The statement level
diagnostics area is not updated with the correct error
status (it remains in Diagnostics_area::DA_EMPTY).
Hence the following check in the Protocol::end_statement()
fails.
516 case Diagnostics_area::DA_EMPTY:
517 default:
518 DBUG_ASSERT(0);
519 error= send_ok(thd->server_status, 0, 0, 0, NULL);
520 break;
The fix is to backport the fix of bugs 14365043, 11761652
and 11746399.
14365043 PROTOCOL::END_STATEMENT(): ASSERTION `0' FAILED
11761652 HA_RND_INIT() RESULT CODE NOT CHECKED
11746399 RETURN VALUES OF HA_INDEX_INIT() AND INDEX_INIT() IGNORED
rb://1227 approved by guilhem and mattiasj.
This allows us to avoid calculating variables (including those involving mutex) that doesn't match the given
wildcard in SHOW STATUS LIKE '...'
Removed all references to active_mi that could cause problems for multi-source replication.
Added START|STOP ALL SLAVES
Added SHOW ALL SLAVES STATUS
include/mysql/plugin.h:
Added SHOW_SIMPLE_FUNC
include/mysql/plugin_audit.h.pp:
Updated .pp file
include/mysql/plugin_auth.h.pp:
Updated .pp file
include/mysql/plugin_ftparser.h.pp:
Updated .pp file
mysql-test/suite/multi_source/info_logs.result:
New columns in SHOW ALL SLAVES STATUS
mysql-test/suite/multi_source/info_logs.test:
Test new syntax
mysql-test/suite/multi_source/simple.result:
New columns in SHOW ALL SLAVES STATUS
mysql-test/suite/multi_source/simple.test:
test new syntax
mysql-test/suite/multi_source/syntax.result:
Updated result
mysql-test/suite/multi_source/syntax.test:
Test new syntax
mysql-test/suite/rpl/r/rpl_skip_replication.result:
Updated result
plugin/semisync/semisync_master_plugin.cc:
SHOW_FUNC -> SHOW_SIMPLE_FUNC
sql/item_create.cc:
Simplify code
sql/lex.h:
Added SLAVES keyword
sql/log.cc:
Constant -> define
sql/log_event.cc:
Added comment
sql/mysqld.cc:
SHOW_FUNC -> SHOW_SIMPLE_FUNC
Made slave_retried_trans, slave_received_heartbeats and heartbeat_period multi-source safe
Clear variable denied_connections and slave_retried_transactions on startup
sql/mysqld.h:
Added slave_retried_transactions
sql/rpl_mi.cc:
create_signed_file_name -> create_logfile_name_with_suffix
Added start_all_slaves() and stop_all_slaves()
sql/rpl_mi.h:
Added prototypes
sql/rpl_rli.cc:
create_signed_file_name -> create_logfile_name_with_suffix
added executed_entries
sql/rpl_rli.h:
Added executed_entries
sql/share/errmsg-utf8.txt:
More and better error messages
sql/slave.cc:
Added more fields to SHOW ALL SLAVES STATUS
Added slave_retried_transactions
Changed constants -> defines
sql/sql_class.h:
Added comment
sql/sql_insert.cc:
active_mi.rli -> thd->rli_slave
sql/sql_lex.h:
Added SQLCOM_SLAVE_ALL_START & SQLCOM_SLAVE_ALL_STOP
sql/sql_load.cc:
active_mi.rli -> thd->rli_slave
sql/sql_parse.cc:
Added START|STOP ALL SLAVES
sql/sql_prepare.cc:
Added SQLCOM_SLAVE_ALL_START & SQLCOM_SLAVE_ALL_STOP
sql/sql_reload.cc:
Made REFRESH RELAY LOG multi-source safe
sql/sql_repl.cc:
create_signed_file_name -> create_logfile_name_with_suffix
Don't send my_ok() from start_slave() or stop_slave() so that we can call it for all master connections
sql/sql_show.cc:
Compare wild cards early for all variables
sql/sql_yacc.yy:
Added START|STOP ALL SLAVES
Added SHOW ALL SLAVES STATUS
sql/sys_vars.cc:
Made replicate_events_marked_for_skip,slave_net_timeout and rpl_filter multi-source safe.
sql/sys_vars.h:
Simplify Sys_var_rpl_filter
Changed names of multi-source log files so that original suffixes are kept.
include/my_sys.h:
Added fn_ext2(), which returns pointer to last '.' in file name
mysql-test/extra/rpl_tests/rpl_max_relay_size.test:
Updated test
mysql-test/suite/multi_source/info_logs-master.opt:
Test with strange file names
mysql-test/suite/multi_source/info_logs.result:
Updated results
mysql-test/suite/multi_source/info_logs.test:
Changed to test with complex names to be able to verify the filename generator code
mysql-test/suite/multi_source/relaylog_events.result:
Updated results
mysql-test/suite/multi_source/reset_slave.result:
Updated results
mysql-test/suite/multi_source/skip_counter.result:
Updated results
mysql-test/suite/multi_source/skip_counter.test:
Added testing of max_relay_log_size
mysql-test/suite/rpl/r/rpl_row_max_relay_size.result:
Updated results
mysql-test/suite/rpl/r/rpl_stm_max_relay_size.result:
Updated results
mysql-test/suite/sys_vars/r/max_relay_log_size_basic.result:
Updated results
mysql-test/suite/sys_vars/t/max_relay_log_size_basic.test:
Updated results
mysys/mf_fn_ext.c:
Added fn_ext2(), which returns pointer to last '.' in file name
sql/log.cc:
Removed some wrong casts
sql/log.h:
Updated comment to reflect new code
sql/log_event.cc:
Updated DBUG_PRINT
sql/mysqld.cc:
Added that max_relay_log_size copies it's values from max_binlog_size
sql/mysqld.h:
Removed max_relay_log_size
sql/rpl_mi.cc:
Changed names of multi-source log files so that original suffixes are kept.
sql/rpl_mi.h:
Updated prototype
sql/rpl_rli.cc:
Updated comment to reflect new code
Made max_relay_log_size depending on master connection.
sql/rpl_rli.h:
Made max_relay_log_size depending on master connection.
sql/set_var.h:
Made option global so that one can check and change min & max values (sorry Sergei)
sql/sql_class.h:
Made max_relay_log_size depending on master connection.
sql/sql_repl.cc:
Updated calls to create_signed_file_name()
sql/sys_vars.cc:
Made max_relay_log_size depending on master connection.
Made old code more reusable
sql/sys_vars.h:
Changed Sys_var_multi_source_uint to ulong to be able to handle max_relay_log_size
Made old code more reusable
and small collateral changes
mysql-test/lib/My/Test.pm:
somehow with "print" we get truncated writes sometimes
mysql-test/suite/perfschema/r/digest_table_full.result:
md5 hashes of statement digests differ, because yacc token codes are different in mariadb
mysql-test/suite/perfschema/r/dml_handler.result:
host table is not ported over yet
mysql-test/suite/perfschema/r/information_schema.result:
host table is not ported over yet
mysql-test/suite/perfschema/r/nesting.result:
this differs, because we don't rewrite general log queries, and multi-statement
packets are logged as a one entry. this result file is identical to what mysql-5.6.5
produces with the --log-raw option.
mysql-test/suite/perfschema/r/relaylog.result:
MariaDB modifies the binlog index file directly, while MySQL 5.6 has a feature "crash-safe binlog index" and modifies a special "crash-safe" shadow copy of the index file and then moves it over. That's why this test shows "NONE" index file writes in MySQL and "MANY" in MariaDB.
mysql-test/suite/perfschema/r/server_init.result:
MariaDB initializes the "manager" resources from the "manager" thread, and starts this thread only when --flush-time is not 0. MySQL 5.6 initializes "manager" resources unconditionally on server startup.
mysql-test/suite/perfschema/r/stage_mdl_global.result:
this differs, because MariaDB disables query cache when query_cache_size=0. MySQL does not
do that, and this causes useless mutex locks and waits.
mysql-test/suite/perfschema/r/statement_digest.result:
md5 hashes of statement digests differ, because yacc token codes are different in mariadb
mysql-test/suite/perfschema/r/statement_digest_consumers.result:
md5 hashes of statement digests differ, because yacc token codes are different in mariadb
mysql-test/suite/perfschema/r/statement_digest_long_query.result:
md5 hashes of statement digests differ, because yacc token codes are different in mariadb
mysql-test/suite/rpl/r/rpl_mixed_drop_create_temp_table.result:
will be updated to match 5.6 when alfranio.correia@oracle.com-20110512172919-c1b5kmum4h52g0ni and anders.song@greatopensource.com-20110105052107-zoab0bsf5a6xxk2y are merged
mysql-test/suite/rpl/r/rpl_non_direct_mixed_mixing_engines.result:
will be updated to match 5.6 when anders.song@greatopensource.com-20110105052107-zoab0bsf5a6xxk2y is merged
QUOTING IN REPLICATION
Problem: Misquoting or unquoted identifiers may lead to
incorrect statements to be logged to the binary log.
Fix: we use specialized functions to append quoted identifiers in
the statements generated by the server.
create table t1 (a smallint primary key auto_increment);
insert into t1 values(32767);
insert into t1 values(NULL);
ERROR 1062 (23000): Duplicate entry '32767' for key 'PRIMARY
Now on always gets error HA_ERR_AUTOINC_RANGE=167 "Out of range value for column", independent of
store engine, SQL Mode or number of inserted rows. This is an unique error that is easier to test for in replication.
Another bug fix is that we now get an error when trying to insert a too big auto-generated value, even in non-strict mode.
Before one get insted the max column value inserted.
This patch also fixes some issues with inserting negative numbers in an auto-increment column.
Fixed the ER_DUP_ENTRY and HA_ERR_AUTOINC_ERANGE are compared the same between master and slave.
This ensures that replication works between an old server to a new slave for auto-increment overflow errors.
Added SQLSTATE errors for handler errors
Smaller bug fixes:
* Added warnings for duplicate key errors when using INSERT IGNORE
* Fixed bug when using --skip-log-bin followed by --log-bin, which did set log-bin to "0"
* Allow one to see how cmake is called by using --just-print --just-configure
BUILD/FINISH.sh:
--just-print --just-configure now shows how cmake would be invoked. Good for understanding parameters to cmake.
cmake/configure.pl:
--just-print --just-configure now shows how cmake would be invoked. Good for understanding parameters to cmake.
include/CMakeLists.txt:
Added handler_state.h
include/handler_state.h:
SQLSTATE for handler error messages.
Required for HA_ERR_AUTOINC_ERANGE, but solves also some other cases.
mysql-test/extra/binlog_tests/binlog.test:
Fixed old wrong behaviour
Added more tests
mysql-test/extra/binlog_tests/binlog_insert_delayed.test:
Reset binary log to only print what's necessary in show_binlog_events
mysql-test/extra/rpl_tests/rpl_auto_increment.test:
Update to new error codes
mysql-test/extra/rpl_tests/rpl_insert_delayed.test:
Ignore warnings as this depends on how the test is run
mysql-test/include/strict_autoinc.inc:
On now gets an error on overflow
mysql-test/r/auto_increment.result:
Update results after fixing error message
mysql-test/r/auto_increment_ranges_innodb.result:
Test new behaviour
mysql-test/r/auto_increment_ranges_myisam.result:
Test new behaviour
mysql-test/r/commit_1innodb.result:
Added warnings for duplicate key error
mysql-test/r/create.result:
Added warnings for duplicate key error
mysql-test/r/insert.result:
Added warnings for duplicate key error
mysql-test/r/insert_select.result:
Added warnings for duplicate key error
mysql-test/r/insert_update.result:
Added warnings for duplicate key error
mysql-test/r/mix2_myisam.result:
Added warnings for duplicate key error
mysql-test/r/myisam_mrr.result:
Added warnings for duplicate key error
mysql-test/r/null_key.result:
Added warnings for duplicate key error
mysql-test/r/replace.result:
Update to new error codes
mysql-test/r/strict_autoinc_1myisam.result:
Update to new error codes
mysql-test/r/strict_autoinc_2innodb.result:
Update to new error codes
mysql-test/r/strict_autoinc_3heap.result:
Update to new error codes
mysql-test/r/trigger.result:
Added warnings for duplicate key error
mysql-test/r/xtradb_mrr.result:
Added warnings for duplicate key error
mysql-test/suite/binlog/r/binlog_innodb_row.result:
Updated result
mysql-test/suite/binlog/r/binlog_row_binlog.result:
Out of range data for auto-increment is not inserted anymore
mysql-test/suite/binlog/r/binlog_statement_insert_delayed.result:
Updated result
mysql-test/suite/binlog/r/binlog_stm_binlog.result:
Out of range data for auto-increment is not inserted anymore
mysql-test/suite/binlog/r/binlog_unsafe.result:
Updated result
mysql-test/suite/innodb/r/innodb-autoinc.result:
Update to new error codes
mysql-test/suite/innodb/r/innodb-lock.result:
Updated results
mysql-test/suite/innodb/r/innodb.result:
Updated results
mysql-test/suite/innodb/r/innodb_bug56947.result:
Updated results
mysql-test/suite/innodb/r/innodb_mysql.result:
Updated results
mysql-test/suite/innodb/t/innodb-autoinc.test:
Update to new error codes
mysql-test/suite/maria/maria3.result:
Updated result
mysql-test/suite/maria/mrr.result:
Updated result
mysql-test/suite/optimizer_unfixed_bugs/r/bug43617.result:
Updated result
mysql-test/suite/rpl/r/rpl_auto_increment.result:
Update to new error codes
mysql-test/suite/rpl/r/rpl_insert_delayed,stmt.rdiff:
Updated results
mysql-test/suite/rpl/r/rpl_loaddatalocal.result:
Updated results
mysql-test/t/auto_increment.test:
Update to new error codes
mysql-test/t/auto_increment_ranges.inc:
Test new behaviour
mysql-test/t/auto_increment_ranges_innodb.test:
Test new behaviour
mysql-test/t/auto_increment_ranges_myisam.test:
Test new behaviour
mysql-test/t/replace.test:
Update to new error codes
mysys/my_getopt.c:
Fixed bug when using --skip-log-bin followed by --log-bin, which did set log-bin to "0"
sql/handler.cc:
Ignore negative values for signed auto-increment columns
Always give an error if we get an overflow for an auto-increment-column (instead of inserting the max value)
Ensure that the row number is correct for the out-of-range-value error message.
******
Fixed wrong printing of column namn for "Out of range value" errors
Fixed that INSERT_ID is correctly replicated also for out-of-range autoincrement values
Fixed that print_keydup_error() can also be used to generate warnings
******
Return HA_ERR_AUTOINC_ERANGE (167) instead of ER_WARN_DATA_OUT_OF_RANGE for auto-increment overflow
sql/handler.h:
Allow INSERT IGNORE to continue also after out-of-range inserts.
Fixed that print_keydup_error() can also be used to generate warnings
sql/log_event.cc:
Added DBUG_PRINT
Fixed the ER_AUTOINC_READ_FAILED, ER_DUP_ENTRY and HA_ERR_AUTOINC_ERANGE are compared the same between master and slave.
This ensures that replication works between an old server to a new slave for auto-increment overflow errors.
sql/sql_insert.cc:
Add warnings for duplicate key errors when using INSERT IGNORE
sql/sql_state.c:
Added handler errors
sql/sql_table.cc:
Update call to print_keydup_error()
storage/innobase/handler/ha_innodb.cc:
Fixed increment handling of auto-increment columns to be consistent with rest of MariaDB.
storage/xtradb/handler/ha_innodb.cc:
Fixed increment handling of auto-increment columns to be consistent with rest of MariaDB.
Introduce a new storage engine API method commit_checkpoint_request().
This is used to replace the fsync() at the end of every storage engine
commit with a single fsync() when a binlog is rotated.
Binlog rotation is now done during group commit instead of being
delayed until unlog(), removing some server stall and avoiding an
expensive lock/unlock of LOCK_log inside unlog().
two tests still fail:
main.innodb_icp and main.range_vs_index_merge_innodb
call records_in_range() with both range ends being open
(which triggers an assert)
Problem:
=======
The return value from my_b_write is ignored by: `my_b_write_quoted',
`my_b_write_bit',`Query_log_event::print_query_header'
Most callers of `my_b_printf' ignore the return value. `log_event.cc'
has many calls to it.
Analysis:
========
`my_b_write' is used to write data into a file. If the write fails it
sets appropriate error number and error message through my_error()
function call and sets the IO_CACHE::error == -1.
`my_b_printf' function is also used to write data into a file, it
internally invokes my_b_write to do the write operation. Upon
success it returns number of characters written to file and on error
it returns -1 and sets the error through my_error() and also sets
IO_CACHE::error == -1. Most of the event specific print functions
for example `Create_file_log_event::print', `Execute_load_log_event::print'
etc are the ones which make several calls to the above two functions and
they do not check for the return value after the 'print' call. All the above
mentioned abuse cases deal with the client side.
Fix:
===
As part of bug fix a check for IO_CACHE::error == -1 has been added at
a very high level after the call to the 'print' function. There are
few more places where the return value of "my_b_write" is ignored
those are mentioned below.
+++ mysys/mf_iocache2.c 2012-06-04 07:03:15 +0000
@@ -430,7 +430,8 @@
memset(buffz, '0', minimum_width - length2);
else
memset(buffz, ' ', minimum_width - length2);
- my_b_write(info, buffz, minimum_width - length2);
+++ sql/log.cc 2012-06-08 09:04:46 +0000
@@ -2388,7 +2388,12 @@
{
end= strxmov(buff, "# administrator command: ", NullS);
buff_len= (ulong) (end - buff);
- my_b_write(&log_file, (uchar*) buff, buff_len);
At these places appropriate return value handlers have been added.
client/mysqlbinlog.cc:
check for IO_CACHE::error == -1 has been added after the call to
the event specific print functions
mysys/mf_iocache2.c:
Added handler to check the written value of `my_b_write'
sql/log.cc:
Added handler to check the written value of `my_b_write'
sql/log_event.cc:
Added error simulation statements in `Create_file_log_event::print`
and `Execute_load_query_log_event::print'
sql/rpl_utility.h:
Removed the extra ';'
Fixes for BUG11761686 left a flaw that managed to slip away from testing.
Only effective filtering branch was actually tested with a regression test
added to rpl_filter_tables_not_exist.
The reason of the failure is destuction of too early mem-root-allocated memory
at the end of the deferred User-var's do_apply_event().
Fixed with bypassing free_root() in the deferred execution branch.
Deallocation of created in do_apply_event() items is done by the base code
through THD::cleanup_after_query() -> free_items() that the parent Query
can't miss.
sql/log_event.cc:
Do not call free_root() in case the deferred User-var event.
Necessary methods to the User-var class are added, do_apply_event() refined.
sql/log_event.h:
Necessary methods to avoid destoying mem-root-based memory at
User-var applying are defined.
Keep track of how many pending XIDs (transactions that are prepared in
storage engine and written into binlog, but not yet durably committed
on disk in the engine) there are in each binlog.
When the count of one binlog drops to zero, write a new binlog checkpoint
event, telling which is the oldest binlog with pending XIDs.
When doing XA recovery after a crash, check the last binlog checkpoint
event, and scan all binlog files from that point onwards for XIDs that
must be committed if found in prepared state inside engine.
Remove the code in binlog rotation that waits for all prepared XIDs to
be committed before writing a new binlog file (this is no longer necessary
when recovery can scan multiple binlog files).
Add function to replace arbitrary event with dummy event.
Add code which uses this to fix the bug that enabling row_annotate events
on the master breaks slaves which do not request such events.
Add that slaves set a variable @mariadb_slave_capability to inform the
master in a robust way about which events it can, and cannot, handle.
Add tests.
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.
The constructor for Query_log_event allocated 2 bytes too few for
extra space needed by Query cache. (Not sure if this is reproducible
in practice, as there are often a couple of extra bytes allocated
for unused string zero terminators, but better safe than sorry).
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.
Problem: mysqlbinlog exits without any error code in case of
file write error. It is because of the fact that the calls
to Log_event::print() method does not return a value and the
thus any error were being ignored.
Resolution: We resolve this problem by checking for the
IO_CACHE::error == -1 after every call to Log_event:: print()
and terminating the further execution.
client/mysqlbinlog.cc:
- handled error conditions during event->print() calls
- added check for error in end_io_cache()
mysys/my_write.c:
Added debug code to simulate file write error.
error returned will be ENOSPC=> error no space on the disk
sql/log_event.cc:
Added debug code to simulate file write error, by reducing the size of io cache.
Problem
========
SQL statements close to the size of max_allowed_packet produce binary
log events larger than 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 + max_event_header
length. Now since the event length exceeds this size master Dump
thread is unable to send the packet on to the slave.
That can happen e.g with row-based replication in Update_rows event.
Fix
====
The problem was fixed by increasing the max_allowed_packet for the
slave's threads (IO/SQL) by increasing it to 1GB.
This is done using the new server option included which is used to
regulate the max_allowed_packet of the slave thread (IO/SQL).
This causes the large packets to be received by the slave and apply
it successfully.
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.
Problem: After the fix for Bug#12589870, a new field that
stores the length of db name was added in the buffer that
stores the query to be executed. Unlike for the plain user
session, the replication execution did not allocate the
necessary chunk in Query-event constructor. This caused an
invalid read while accessing this field.
Solution: We fix this problem by allocating a necessary chunk
in the buffer created in the Query_log_event::Query_log_event()
and store the length of database name.
sql/log_event.cc:
Added a new field in the buffer created in the
Query_log_event's constructor and store the length
of database name.
