is possible):
When skipping the beginning of a transaction starting with BEGIN, the OPTION_BEGIN
flag was not set correctly, which caused the slave to not recognize that it was
inside a group. This patch sets the OPTION_BEGIN flag for BEGIN, COMMIT, ROLLBACK,
and XID events. It also adds checks if inside a group before decreasing the
slave skip counter to zero.
Begin_query_log_event was not marked that it could not end a group, which is now
corrected.
Refactoring code to add parameter to pack() and unpack() functions with
purpose of indicating if data should be packed in little-endian or
native order. Using new functions to always pack data for binary log
in little-endian order. The purpose of this refactoring is to allow
proper implementation of endian-agnostic pack() and unpack() functions.
Eliminating several versions of virtual pack() and unpack() functions
in favor for one single virtual function which is overridden in
subclasses.
Implementing pack() and unpack() functions for some field types that
packed data in native format regardless of the value of the
st_table_share::db_low_byte_first flag.
The field types that were packed in native format regardless are:
Field_real, Field_decimal, Field_tiny, Field_short, Field_medium,
Field_long, Field_longlong, and Field_blob.
Before the patch, row-based logging wrote the rows incorrectly on
big-endian machines where the storage engine defined its own
low_byte_first() to be FALSE on big-endian machines (the default
is TRUE), while little-endian machines wrote the fields in correct
order. The only known storage engine that does this is NDB. In effect,
this means that row-based replication from or to a big-endian
machine where the table was using NDB as storage engine failed if the
other engine was either non-NDB or on a little-endian machine.
With this patch, row-based logging is now always done in little-endian
order, while ORDER BY uses the native order if the storage engine
defines low_byte_first() to return FALSE for big-endian machines.
In addition, the max_data_length() function available in Field_blob
was generalized to the entire Field hierarchy to give the maximum
number of bytes that Field::pack() will write.
using TPC-B):
Problem: A RBR event can contain incomplete row data (only key value and
fields which have been changed). In that case, when the row is unpacked
into record and written to a table, the missing fields get incorrect NULL
values leading to master-slave inconsistency.
Solution: Use values found in slave's table for columns which are not given
in the rows event. The code for writing a single row uses the following
algorithm:
1. unpack row_data into table->record[0],
2. try to insert record,
3. if duplicate record found, fetch it into table->record[0],
4. unpack row_data into table->record[0],
5. write table->record[0] into the table.
Where row_data is the row as stored in the data area of a rows event.
Thus:
a) unpacking of row_data happens at the time when row is written into
a table,
b) when unpacking (in step 4), only columns present in row_data are
overwritten - all other columns remain as they were found in the table.
Since all data needed for the above algorithm is stored inside
Rows_log_event class, functions which locate and write rows are turned
into methods of that class.
replace_record() -> Rows_log_event::write_row()
find_and_fetch_row() -> Rows_log_event::find_row()
Both methods take row data from event's data buffer - the row being
processed is pointed by m_curr_row. They unpack the data as needed into
table's record buffers record[0] or record[1]. When row is unpacked,
m_curr_row_end is set to point at next row in the data buffer.
Other changes introduced in this changeset:
- Change signature of unpack_row(): don't report errors and don't
setup table's rw_set here. Errors can happen only when setting default
values in prepare_record() function and are detected there.
- In Rows_log_event and derived classes, don't pass arguments to
the execution primitives (do_...() member functions) but use class
members instead.
- Move old row handling code into log_event_old.cc to be used by
*_rows_log_event_old classes.
Also, a new test rpl_ndb_2other is added which tests basic replication
from master using ndb tables to slave storing the same tables using
(possibly) different engine (myisam,innodb).
Test is based on existing tests rpl_ndb_2myisam and rpl_ndb_2innodb.
However, these tests doesn't work for various reasons and currently are
disabled (see BUG#19227).
The new test differs from the ones it is based on as follows:
1. Single test tests replication with different storage engines on slave
(myisam, innodb, ndb).
2. Include file extra/rpl_tests/rpl_ndb_2multi_eng.test containing
original tests is replaced by extra/rpl_tests/rpl_ndb_2multi_basic.test
which doesn't contain tests using partitioned tables as these don't work
currently. Instead, it tests replication to a slave which has more or
less columns than master.
3. Include file include/rpl_multi_engine3.inc is replaced with
include/rpl_multi_engine2.inc. The later differs by performing slightly
different operations (updating more than one row in the table) and
clearing table with "TRUNCATE TABLE" statement instead of "DELETE FROM"
as replication of "DELETE" doesn't work well in this setting.
4. Slave must use option --log-slave-updates=0 as otherwise execution of
replication events generated by ndb fails if table uses a different
storage engine on slave (see BUG#29569).
This patch adds functionality to row-based replication to ensure the
slave's column sizes are >= to that of the master.
It also includes some refactoring for the code from WL#3228.
This patch adds the ability to store extra field metadata in the table
map event. This data can include pack_length() or field_lenght() for
fields such as CHAR or VARCHAR enabling developers to add code that
can check for compatibilty between master and slave columns. More
importantly, the extra field metadata can be used to store data from the
master correctly should a VARCHAR field on the master be <= 255 bytes
while the same field on the slave is > 255 bytes.
The patch also includes the needed changes to unpack to ensure that data
which is smaller on the master can be unpacked correctly on the slave.
WL#3915 : (NDB) master's cols > slave
Slave starts accepting and handling rows of master's tables which have more columns.
The most important part of implementation is how to caclulate the amount of bytes to
skip for unknown by slave column.
