CHANGE MASTER TO command required the value for RELAY_LOG_FILE to
be an absolute path, which was different from the requirement of
MASTER_LOG_FILE.
This patch fixed the problem by changing the value for RELAY_LOG_FILE
to be the basename of the log file as that for MASTER_LOG_FILE.
rpl_slave_skip fails randomly on PB2. This patch fixes the failure by
setting explicit wait for SQL thread to stop, instead of the
wait_for_slave_to_stop mysqltest command, after a start until command
is executed.
NOTE: Backporting the patch to next-mr.
The fix proposed in BUG#35542 and BUG#31665 introduces a performance issue
when fsyncing the master.info, relay.info and relay-log.bin* after #th events.
Although such solution has been proposed to reduce the probability of corrupted
files due to a slave-crash, the performance penalty introduced by it has
made the approach impractical for highly intensive workloads.
In a nutshell, the option --syn-relay-log proposed in BUG#35542 and BUG#31665
simultaneously fsyncs master.info, relay-log.info and relay-log.bin* and
this is the main source of performance issues.
This patch introduces new options that give more control to the user on
what should be fsynced and how often:
1) (--sync-master-info, integer) which syncs the master.info after #th event;
2) (--sync-relay-log, integer) which syncs the relay-log.bin* after #th
events.
3) (--sync-relay-log-info, integer) which syncs the relay.info after #th
transactions.
To provide both performance and increased reliability, we recommend the following
setup:
1) --sync-master-info = 0 eventually the operating system will fsync it;
2) --sync-relay-log = 0 eventually the operating system will fsync it;
3) --sync-relay-log-info = 1 fsyncs it after every transaction;
Notice, that the previous setup does not reduce the probability of
corrupted master.info and relay-log.bin*. To overcome the issue, this patch also
introduces a recovery mechanism that right after restart throws away relay-log.bin*
retrieved from a master and updates the master.info based on the relay.info:
4) (--relay-log-recovery, boolean) which enables a recovery mechanism that
throws away relay-log.bin* after a crash.
However, it can only recover the incorrect binlog file and position in master.info,
if other informations (host, port password, etc) are corrupted or incorrect,
then this recovery mechanism will fail to work.
vs not null
NOTE: Backporting the patch to next-mr.
The replication was generating corrupted data, warning messages on Valgrind
and aborting on debug mode while replicating a "null" to "not null" field.
Specifically the unpack_row routine, was considering the slave's table
definition and trying to retrieve a field value, where there was nothing to be
retrieved, ignoring the fact that the value was defined as "null" by the master.
To fix the problem, we proceed as follows:
1 - If it is not STRICT sql_mode, implicit default values are used, regardless
if it is multi-row or single-row statement.
2 - However, if it is STRICT mode, then a we do what follows:
2.1 If it is a transactional engine, we do a rollback on the first NULL that is
to be set into a NOT NULL column and return an error.
2.2 If it is a non-transactional engine and it is the first row to be inserted
with multi-row, we also return the error. Otherwise, we proceed with the
execution, use implicit default values and print out warning messages.
Unfortunately, the current patch cannot mimic the behavior showed by the master
for updates on multi-tables and multi-row inserts. This happens because such
statements are unfolded in different row events. For instance, considering the
following updates and strict mode:
(master)
create table t1 (a int);
create table t2 (a int not null);
insert into t1 values (1);
insert into t2 values (2);
update t1, t2 SET t1.a=10, t2.a=NULL;
t1 would have (10) and t2 would have (0) as this would be handled as a
multi-row update. On the other hand, if we had the following updates:
(master)
create table t1 (a int);
create table t2 (a int);
(slave)
create table t1 (a int);
create table t2 (a int not null);
(master)
insert into t1 values (1);
insert into t2 values (2);
update t1, t2 SET t1.a=10, t2.a=NULL;
On the master t1 would have (10) and t2 would have (NULL). On
the slave, t1 would have (10) but the update on t1 would fail.
beyond unsigned long.
BUG#44779: binlog.binlog_max_extension may be causing failure on
next test in PB
NOTE1: this is the backport to next-mr.
NOTE2: already includes patch for BUG#44779.
Binlog file extensions would turn into negative numbers once the
variable used to hold the value reached maximum for signed
long. Consequently, incrementing value to the next (negative) number
would lead to .000000 extension, causing the server to fail.
This patch addresses this issue by not allowing negative extensions
and by returning an error on find_uniq_filename, when the limit is
reached. Additionally, warnings are printed to the error log when the
limit is approaching. FLUSH LOGS will also report warnings to the
user, if the extension number has reached the limit. The limit has been
set to 0x7FFFFFFF as the maximum.
NOTE: this is the backport to next-mr.
This patch addresses the bug reported by checking wether
host argument is an empty string or not. If empty, an error is
reported to the client, otherwise continue normally.
This commit is based on the originally proposed patch and adds
a test case as requested during review as well as refines comments,
and makes test case result file less verbose (compared to previous patch).
NOTE: this is the backport to next-mr.
When using replication, the slave will not log any slow query logs queries
replicated from the master, even if the option "--log-slow-slave-statements"
is set and these take more than "log_query_time" to execute.
In order to log slow queries in replicated thread one needs to set the
--log-slow-slave-statements, so that the SQL thread is initialized with the
correct switch. Although setting this flag correctly configures the slave
thread option to log slow queries, there is an issue with the condition that
is used to check whether to log the slow query or not. When replaying binlog
events the statement contains the SET TIMESTAMP clause which will force the
slow logging condition check to fail. Consequently, the slow query logging will
not take place.
This patch addresses this issue by removing the second condition from the
log_slow_statements as it prevents slow queries to be binlogged and seems
to be deprecated.
NOTE: Backporting the patch to next-mr.
The reason of the bug was incompatibile with the master side behaviour.
INSERT query on the master is allowed to insert into a table without specifying
values of DEFAULT-less fields if sql_mode is not strict.
Fixed with checking sql_mode by the sql thread to decide how to react.
Non-strict sql_mode should allow Write_rows event to complete.
todo: warnings can be shown via show slave status, still this is a
separate rather general issue how to show warnings for the slave threads.
files
NOTE: this is the backport to next-mr.
SHOW BINLOG EVENTS does not work with relay log files. If issuing
"SHOW BINLOG EVENTS IN 'relay-log.000001'" in a non-empty relay
log file (relay-log.000001), mysql reports empty set.
This patch addresses this issue by extending the SHOW command
with RELAYLOG. Events in relay log files can now be inspected by
issuing SHOW RELAYLOG EVENTS [IN 'log_name'] [FROM pos] [LIMIT
[offset,] row_count].
When setting AUTOCOMMIT=1 after starting a transaction, the binary log
did not commit the outstanding transaction. The reason was that the binary
log commit function saw the values of the new settings, deciding that there
were nothing to commit.
Fixed the problem by moving the implicit commit to before the thread option
flags were changed, so that the binary log sees the old values of the flags
instead of the values they will take after the statement.
slave leaves slave unstable
Problem: when replicating from non-transactional to
transactional engine with autocommit off, no BEGIN/COMMIT
is written to the binlog. When the slave replicates, it
will start a transaction that never ends.
Fix: Force autocommit=on on slave by always replicating
autocommit=1 from the master.
If an EVENT is created without the DEFINER clause set explicitly or with it set
to CURRENT_USER, the master and slaves become inconsistent. This issue stems from
the fact that in both cases, the DEFINER is set to the CURRENT_USER of the current
thread. On the master, the CURRENT_USER is the mysqld's user, while on the slave,
the CURRENT_USER is empty for the SQL Thread which is responsible for executing
the statement.
To fix the problem, we do what follows. If the definer is not set explicitly,
a DEFINER clause is added when writing the query into binlog; if 'CURRENT_USER' is
used as the DEFINER, it is replaced with the value of the current user before
writing to binlog.
Slave does not correctly handle "expected errors" leading to inconsistencies
between the mater and slave. Specifically, when a statement changes both
transactional and non-transactional tables, the transactional changes are
automatically rolled back on the master but the slave ignores the error and
does not roll them back thus leading to inconsistencies.
To fix the problem, we automatically roll back a statement that fails on
the slave but note that the transaction is not rolled back unless a "rollback"
command is in the relay log file.
binlog
Mixing transactional (T) and non-transactional (N) tables on behalf of a
transaction may lead to inconsistencies among masters and slaves in STATEMENT
mode. The problem stems from the fact that although modifications done to
non-transactional tables on behalf of a transaction become immediately visible
to other connections they do not immediately get to the binary log and therefore
consistency is broken. Although there may be issues in mixing T and M tables in
STATEMENT mode, there are safe combinations that clients find useful.
In this bug, we fix the following issue. Mixing N and T tables in multi-level
(e.g. a statement that fires a trigger) or multi-table table statements (e.g.
update t1, t2...) were not handled correctly. In such cases, it was not possible
to distinguish when a T table was updated if the sequence of changes was N and T.
In a nutshell, just the flag "modified_non_trans_table" was not enough to reflect
that both a N and T tables were changed. To circumvent this issue, we check if an
engine is registered in the handler's list and changed something which means that
a T table was modified.
Check WL 2687 for a full-fledged patch that will make the use of either the MIXED or
ROW modes completely safe.
In STATEMENT based replication, a statement that failed on the master but that
updated non-transactional tables is written to binary log with the error code
appended to it. On the slave, the statement is executed and the same error is
expected. However, when an "expected error" did not happen on the slave and was
either ignored or was related to a concurrency issue on the master, the slave
did not rollback the effects of the statement and as such inconsistencies might
happen.
To fix the problem, we automatically rollback a statement that should have
failed on a slave but succeded and whose expected failure is either ignored or
stems from a concurrency issue on the master.
If using statement based replication (SBR), repeatedly calling
statements which are unsafe for SBR will cause a warning message
to be written to the error for each statement. This might lead
to filling up the error log and there is no way to disable this
behavior.
The solution is to only log these message (about statements unsafe
for statement based replication) if the log_warnings option is set.
For example:
SET GLOBAL LOG_WARNINGS = 0;
INSERT INTO t1 VALUES(UUID());
SET GLOBAL LOG_WARNINGS = 1;
INSERT INTO t1 VALUES(UUID());
In this case the message will be printed only once:
[Warning] Statement may not be safe to log in statement format.
Statement: INSERT INTO t1 VALUES(UUID())
If the log_bin_trust_function_creators option is not defined, creating a stored
function requires either one of the modifiers DETERMINISTIC, NO SQL, or READS
SQL DATA. Executing a stored function should also follows the same rules if in
STATEMENT mode. However, this was not happening and a wrong error was being
printed out: ER_BINLOG_ROW_RBR_TO_SBR.
The patch makes the creation and execution compatible and prints out the correct
error ER_BINLOG_UNSAFE_ROUTINE when a stored function without one of the modifiers
above is executed in STATEMENT mode.
to wrong result
When using MIXED mode and issuing 'CREATE TEMPORARY TABLE t_tmp',
the statement is logged if the current binlogging mode is
STATEMENT. This causes the slave to replay the instruction and
create the temporary table as well. If there is no switch to ROW
mode, and later on a 'DROP TEMPORARY TABLE t_tmp' is issued, then
this statement will also be logged and the slave will
remove/close the temporary table.
However, if there is a switch to ROW mode between the CREATE and
DROP TEMPORARY table, the DROP statement will not be logged,
leaving the slave with a dangling temporary table.
This patch addresses this, by always logging a DROP TEMPORARY
TABLE IF EXISTS when in mixed mode and a drop statement is issued
for temporary table(s).
binlog
The fix for BUG 43929 introduced a regression issue. In a nutshell, when a
statement that changes a non-transactional table fails, it is written to the
binary log with the error code appended. Unfortunately, after BUG 43929, this
failure was flushing the transactional chace causing mismatch between execution
and logging histories. To fix this issue, we avoid flushing the transactional
cache when a commit or rollback is not issued.
The "get_master_version_and_clock(...)" function in sql/slave.cc ignores
error and passes directly when queries fail, or queries succeed
but the result retrieved is empty.
The "get_master_version_and_clock(...)" function should try to reconnect master
if queries fail because of transient network problems, and fail otherwise.
The I/O thread should print a warning if the some system variables do not
exist on master (very old master)
