* MDEV-16509 Improve wsrep commit performance with binlog disabled
Release commit order critical section early after trx_commit_low() if
binlog is not transaction coordinator. In order to avoid two phase commit,
binlog_hton is not registered for THD during IO_CACHE population.
Implemented a test which verifies that the transactions release
commit order early.
This optimization will change behavior during recovery as the commit
is not two phase when binlog is off. Fixed and recorded wsrep-recover-v25
and wsrep-recover to match the behavior.
* MDEV-18730 Ordering for wsrep binlog group commit
Previously out of order execution was allowed for wsrep commits.
Established proper ordering by populating wait_for_commit
for every wsrep THD and making group commit leader to wait for
prior commits before proceeding to trx_group_commit_leader().
* MDEV-18730 Added a test case to verify correct commit ordering
* MDEV-16509, MDEV-18730 Review fixes
Use WSREP_EMULATE_BINLOG() macro to decide if the binlog_hton
should be registered. Whitespace/syntax fixes and cleanups.
* MDEV-16509 Require binlog for galera_var_innodb_disallow_writes test
If the commit to InnoDB is done in one phase, the native InnoDB behavior
is that the transaction is committed in memory before it is persisted to
disk. This means that the innodb_disallow_writes=ON may not prevent
transaction to become visible to other readers before commit is completely
over. On the other hand, if the commit is two phase (as it is with binlog),
the transaction will be blocked in prepare phase.
Fixed the test to use binlog, which enforces two phase commit, which
in turn makes commit to block before the changes become visible to
other connections. This guarantees that the test produces expected
result.
Removed redundant initialisation in unireg_init(): already done by
mysql_init_variables().
Slave threads already check THD::killed, which eliminates the need to
check abort_loop.
Removed unused wsrep_kill_mysql().
Refactored wsrep patch to not use LOCK_thread_count and COND_thread_count anymore.
This has partially been replaced by using old LOCK_wsrep_slave_threads mutex.
For slave thread count change waiting, new COND_wsrep_slave_threads signal has been added
Added LOCK_wsrep_cluster_config mutex to control that cluster address change cannot happen in parallel
Protected wsrep_slave_threads variable changes with LOCK_cluster_config mutex
This is for avoiding concurrent slave thread count and cluster joining operations to happen
Fixes according to Teemu's review
* Removed all references related to wsrep_thd_pool (which was removed)
* Removed unused declarations in wsrep_schema.h
* The following would result invalid reads in
Wsrep_schema::replay_transaction():
```
frag_table->field[4]->val_str(&buf);
Wsrep_schema_impl::end_index_scan(frag_table);
Wsrep_schema_impl::finish_stmt(thd);
ret= wsrep_apply_events(thd, rli, buf.c_ptr_safe(), buf.length());
```
because `buf` was accessed after closing the table. The fix is to
perform storage reads using a different THD.
* In Wsrep_schema::recover_sr_transactions(), cluster_table was opened
for write, however it is only read here. And frag_table was opened
for read, wereas write is potentially needed.
Also, avoid copy caused by String::c_ptr() to zero terminate the c
string, use c_ptr_quick instead.
Global variable wsrep_debug now can be used to filter wsrep-lib messages based on debug level provided.
Type of wsrep_debug is now set to be unsigned int, so tests and configuration files changed accordingly.
If wsrep_load_data_splitting is configured, change streaming replication
parameters internally to match the original behavior, i.e. replicate
on every 10000 rows. After load data is over, restore original
streaming replication settings.
Removed redundant wsrep_tc_log_commit().
Problem was that controlling connection i.e. connection that
executed the query SET GLOBAL wsrep_reject_queries = ALL_KILL;
was also killed but server would try to send result from that
query to controlling connection resulting a assertion
mysqld: /home/jan/mysql/10.2-sst/include/mysql/psi/mysql_socket.h:738: inline_mysql_socket_send: Assertion `mysql_socket.fd != -1' failed.
as socket was closed when controlling connection was closed.
wsrep_close_client_connections()
Do not close controlling connection and instead of
wsrep_close_thread() we do now soft kill by THD::awake
wsrep_reject_queries_update()
Call wsrep_close_client_connections using current thd.
Problem was that controlling connection i.e. connection that
executed the query SET GLOBAL wsrep_reject_queries = ALL_KILL;
was also killed but server would try to send result from that
query to controlling connection resulting a assertion
mysqld: /home/jan/mysql/10.2-sst/include/mysql/psi/mysql_socket.h:738: inline_mysql_socket_send: Assertion `mysql_socket.fd != -1' failed.
as socket was closed when controlling connection was closed.
wsrep_close_client_connections()
Do not close controlling connection and instead of
wsrep_close_thread() we do now soft kill by THD::awake
wsrep_reject_queries_update()
Call wsrep_close_client_connections using current thd.
This is used for controlling whether to use a new/optimized
certification rules or the old/classic ones that could cause more
certification failures - when foreign keys are used and two INSERTs are
done concurrently to the child table from different nodes.
(cherry picked from commit 815d73e6af8daace6262ab63ca6c043ffc4204b3)
If we have a 2+ node cluster which is replicating from an async master
and the binlog_format is set to STATEMENT and multi-row inserts are executed
on a table with an auto_increment column such that values are automatically
generated by MySQL, then the server node generates wrong auto_increment
values, which are different from what was generated on the async master.
The causes and fixes:
1. We need to improve processing of changing the auto-increment values
after changing the cluster size.
2. If wsrep auto_increment_control switched on during operation of
the node, then we should immediately update the auto_increment_increment
and auto_increment_offset global variables, without waiting of the next
invocation of the wsrep_view_handler_cb() callback. In the current version
these variables retain its initial values if wsrep_auto_increment_control
is switched on during operation of the node, which leads to inconsistent
results on the different nodes in some scenarios.
3. If wsrep auto_increment_control switched off during operation of the node,
then we must return the original values of the auto_increment_increment and
auto_increment_offset global variables, as the user has set. To make this
possible, we need to add a "shadow copies" of these variables (which stores
the latest values set by the user).
Adding a FK constraint to an existing table (ALTER TABLE ADD FOREIGN
KEY) causes the applier to fail, if a concurrent DML statement that
violate the new constraint (i.e. a DELETE or UPDATE of record in the
parent table).
For exmaple, the following scenario causes a crash in the applier:
1. ALTER successfully adds FK constraint in node_1
2. On node_2 is UPDATE is in pre_commit() and has certified successfully
3. ALTER is delivered in node_2 and BF aborts DML
4. Applying UPDATE event causes FK violation in node_1
To avoid this situation it is necessary for UPDATE to fail during
certification. And for the UPDATE to fail certfication it is necessary
that ALTER appends certification keys for both the child and the parent
table. Before this patch, ALTER TABLE ADD FK only appended keys for
child table which is ALTERed.
These test can sporadically show mutex deadlock warnings between LOCK_wsrep_thd
and LOCK_thd_data mutexes. This means that these mutexes can be locked in opposite
order by different threads, and thus result in deadlock situation.
To fix such issue, the locking policy of these mutexes should be revised and
enforced to be uniform. However, a quick code review shows that the number of
lock/unlock operations for these mutexes combined is between 100-200, and all these
mutex invocations should be checked/fixed.
On the other hand, it turns out that LOCK_wsrep_thd is used for protecting access to
wsrep variables of THD (wsrep_conflict_state, wsrep_query_state), whereas LOCK_thd_data
protects query, db and mysys_var variables in THD. Extending LOCK_thd_data to protect
also wsrep variables looks like a viable solution, as there should not be a use case
where separate threads need simultaneous access to wsrep variables and THD data variables.
In this commit LOCK_wsrep_thd mutex is refactored to be replaced by LOCK_thd_data.
By bluntly replacing LOCK_wsrep_thd by LOCK_thd_data, will result in double locking
of LOCK_thd_data, and some adjustements have been performed to fix such situations.
Removed including wsrep_api.h from service_wsrep.h. This caused
various kinds of collisions with definitions when wsrep is
not supposed to be built in. Defined functions wsrep_xid_seqno()
and wsrep_xid_uuid() in wsrep_dummy.cc. Replaced wsrep_seqno_t
with long long where wsrep_api.h is not included.
Removed wsrep_xid_seqno() macro from wsrep_mysqld.h and made
wsrep code using wsrep_xid_seqno() in handler.cc to be compiled
in only if WITH_WSREP is ON.
Included wsrep_api.h for mariabackup if WITH_WSREP is ON.
This was done in, among other things:
- thd->db and thd->db_length
- TABLE_LIST tablename, db, alias and schema_name
- Audit plugin database name
- lex->db
- All db and table names in Alter_table_ctx
- st_select_lex db
Other things:
- Changed a lot of functions to take const LEX_CSTRING* as argument
for db, table_name and alias. See init_one_table() as an example.
- Changed some function arguments from LEX_CSTRING to const LEX_CSTRING
- Changed some lists from LEX_STRING to LEX_CSTRING
- threads_mysql.result changed because process list_db wasn't always
correctly updated
- New append_identifier() function that takes LEX_CSTRING* as arguments
- Added new element tmp_buff to Alter_table_ctx to separate temp name
handling from temporary space
- Ensure we store the length after my_casedn_str() of table/db names
- Removed not used version of rename_table_in_stat_tables()
- Changed Natural_join_column::table_name and db_name() to never return
NULL (used for print)
- thd->get_db() now returns db as a printable string (thd->db.str or "")
* changed thd_binlog_format to return configured binlog format in wsrep execution,
regardless of binlogging setting (i.e. with or without binlogging)
* thd_binlog_format is used in innobase::write_row(), and would return confusing
result there when log_bin==OFF
