The current semi-sync binlog fail-over recovery process uses
rpl_semi_sync_slave_enabled==TRUE as its condition to truncate a
primary server’s binlog, as it is anticipating the server to re-join
a replication topology as a replica. However, for servers configured
with both rpl_semi_sync_master_enabled=1 and
rpl_semi_sync_slave_enabled=1, if a primary is just re-started (i.e.
retaining its role as master), it can truncate its binlog to drop
transactions which its replica(s) has already received and executed.
If this happens, when the replica reconnects, its gtid_slave_pos can
be ahead of the recovered primary’s gtid_binlog_pos, resulting in an
error state where the replica’s state is ahead of the primary’s.
This patch changes the condition for semi-sync recovery to truncate
the binlog to instead use the configuration variable
--init-rpl-role, when set to SLAVE. This allows for both
rpl_semi_sync_master_enabled and rpl_semi_sync_slave_enabled to be
set for a primary that is restarted, and no transactions will be
lost, so long as --init-rpl-role is not set to SLAVE.
MDEV-33546: Rpl_semi_sync_slave_status is ON When Replication Is Not Configured
If a server has a default configuration (e.g. in a my.cnf file) with
rpl_semi_sync_slave_enabled set, on server start, the corresponding
rpl_semi_sync_slave_status variable will also be ON initially, even
if the slave was never configured/started. This is because the
Repl_semi_sync_slave initialization logic (function init_object())
sets the running status to the enabled value during
init_server_components().
This patch fixes this by removing the statement which sets the
semi-sync slave running status from the initialization logic. An
additional change needed from this is to semi-sync recovery: this
status variable was used as a condition to determine binlog
truncation during server recovery. This patch also switches this
condition to reference the global rpl_semi_sync_slave_enabled
variable. Though note, the semi-sync recovery condition is to be
changed entirely with the MDEV-33424 agenda.
Reviewed By:
============
Andrei Elkin <email address hidden>
MDEV-33502: part#4: Dont make redundant extra(HA_EXTRA_[NO]_KEYREAD) calls
In most cases, ha_partition forwards calls to extra() to all
locked_partitions. It doesn't make sense to forward some calls for
partitions that were pruned away.
This patch introduces ha_partition::loop_read_partitions and makes
these calls use it:
MDEV-33508 Performance regression due to frequent scan of full buf_pool.flush_list
buf_flush_page_cleaner(): Remove a loop that had originally been added
in commit 9d1466522ea92963ac6ca16b597392714280c9f1 (MDEV-32029) and made
redundant by commit 5b53342a6a59ae1141b2a46467954fc3836f8e80 (MDEV-32588).
Starting with commit d34479dc664d4cbd4e9dad6b0f92d7c8e55595d1 (MDEV-33053)
this loop would cause a significant performance regression in workloads
where buf_pool.need_LRU_eviction() constantly holds in
buf_flush_page_cleaner().
MDEV-33502 Slowdown when running nested statement with many partitions
This change was triggered to help some MariaDB users with close to
10000 bits in their bitmaps.
- Change underlaying storage to be 64 bit instead of 32bit.
- This reduses number of loops to scan bitmaps.
- This can cause some bitmaps to be 4 byte large.
- Ensure that all not used top-bits are always 0 (simplifes code as
the last 64 bit storage is not a special case anymore).
- Use my_find_first_bit() to find the first set bit which is much faster
than scanning trough things byte by byte and then bit by bit.
Other things:
- Added a bool to remember if my_bitmap_init() did allocate the bitmap
array. my_bitmap_free() will only free arrays it did allocate.
This allowed me to remove setting 'bitmap=0' before calling
my_bitmap_free() for cases where the bitmap's where allocated externally.
- my_bitmap_init() sets bitmap to 0 in case of failure.
- Added 'universal' asserts to most bitmap functions.
- Change all remaining calls to bitmap_init() to my_bitmap_init().
- To finish the change from 2014.
- Changed all usage of uint32 in my_bitmap.h to my_bitmap_map.
- Updated bitmap_copy() to handle bitmaps of different size.
- Removed const from bitmap_exists_intersection() as this caused casts
on all usage.
- Removed not used function bitmap_set_above().
- Renamed create_last_word_mask() to create_last_bit_mask() (to match
name changes in my_bitmap.cc)
- Extended bitmap-t with test for more bitmap functions.
