In wsrep BF we have already took lock_sys and trx
mutex either on wsrep_abort_transaction() or
before wsrep_kill_victim(). In replication we
could own lock_sys mutex taken in
lock_deadlock_check_and_resolve().
Backport pull request #125 from grooverdan/MDEV-8923_innodb_buffer_pool_dump_pct to 10.0
WL#6504 InnoDB buffer pool dump/load enchantments
This patch consists of two parts:
1. Dump only the hottest N% of the buffer pool(s)
2. Prevent hogging the server duing BP load
From MySQL - commit b409342c43ce2edb68807100a77001367c7e6b8e
Add testcases for innodb_buffer_pool_dump_pct_basic.
Part of the code authored by Daniel Black
As galera node (slave) received query log events from an async
replication master, it partially wrote the updates made to replication
state table (mysql.gtid_slave_pos) to galera transaction writeset post
TOI. As a result, the transaction handle, thus created within galera,
was never freed/purged as the corresponding trx did not commit.
Thus, it kept piling up for every query log event and was only reclaimed
upon server shutdown when the transaction map object got destructed.
Fixed by making sure that updates in replication slave state table
are not written to galera transaction writeset and thus, not replicated
to other nodes.
fix innodb auto-increment handling
three bugs:
1. innobase_next_autoinc treated the case of current<offset incorrectly
2. ha_innobase::get_auto_increment didn't recalculate current when increment changed
3. ha_innobase::get_auto_increment didn't pass offset down to innobase_next_autoinc
Analysis: There were two problems. (1) if partition table was
created using lower_case_tables = 1 on windows we did find the
correct table but we did not set share->ib_table correctly.
(2) we did open table on dictionary but did not increase
mysql_open_tables.
Fix: In xtradb allow access to tables with incorrect
lower case names (warning is printed to error log). If
table is opened increase mysql_open_tables count to avoid
crash on flush tables.
Analysis: debug only assertion I_S function (IS is XtraDB feature) is calling
buf_block_get_frame on any page it reads, which debug-asserts that the page is
buffer-fixed, which is not the case in I_S query.
Fixed by holding the buffer page mutex while the fields are read directly.
Analysis: Current implementation will write and read at least one block
(sort_buffer_size bytes) from disk / index even if that block does not
contain any records.
Fix: Avoid writing / reading empty blocks to temporary files (disk).
Analysis: We are alreading holing lock_sys mutex when we call thd::awake.
This could lead mutex deadlock if trx->current_lock_mutex_owner is not
correctly set.
Fix: Make sure that trx->current_lock_mutex_owner is correctly set.
When wsrep is enabled, for any update on innodb tables, the
corresponding keys are appended to galera's transaction writeset
(wsrep_append_keys()). However, for LOAD DATA, this got skipped
if binary logging was disabled or it was non-ROW based.
As a result, while the updates from LOAD DATA on non-partitioned
tables replicated fine as wsrep implicitly enables binary logging
(if not enabled, explicitly), the same did not work on partitioned
tables as for partitioned tables the binary logging gets disabled
temporarily (ha_partition::write_row()).
Fixed by removing the unwanted conditions from the check.
Also backported some changes from 10.0-galera to make sure
wsrep_load_data_splitting affects LOAD DATA commands only.
Analysis: At check_trx_exists function InnoDB allocates
a new trx if no trx is found from thd but this newly
allocated trx is not registered to thd. This is unsafe,
because nothing prevents InnoDB plugin from being uninstalled
while there's active transaction. This can cause crashes, hang
and any other odd behavior. It may also corrupt stack, as
functions pointers are not available after dlclose.
Fix: The fix is to use thd_set_ha_data() when
manipulating per-connection handler data. It does appropriate
plugin locking.
Analysis; Problem is that InnoDB does not have support for generating
CURRENT_TIMESTAMP or constant default.
Fix: Add additional check if column has changed from NULL -> NOT NULL
and column default has changed. If this is is first column definition
whose SQL type is TIMESTAMP and it is defined as NOT NULL and
it has either constant default or function default we must use
"Copy" method for alter table.
Analysis: Problem is that SQL-layer calls handler API after storage
engine has already returned error state. InnoDB does internal
rollback when it notices transaction error (e.g. lock wait timeout,
deadlock, etc.) and after this transaction is not naturally in
correct state to continue.
Fix: Do not continue fetch operations if transaction is not started.
