Problem was that tests select INFORMATION_SCHEMA.PROCESSLIST processes
from user system user and empty state. Thus, there is not clear
state for slave threads.
Changes:
- Added new status variables that store current amount of applier threads
(wsrep_applier_thread_count) and rollbacker threads
(wsrep_rollbacker_thread_count). This will make clear how many slave threads
of certain type there is.
- Added THD state "wsrep applier idle" when applier slave thread is
waiting for work. This makes finding slave/applier threads easier.
- Added force-restart option for mtr to always restart servers between tests
to avoid race on start of the test
- Added wait_condition_with_debug to wait until the passed statement returns
true, or the operation times out. If operation times out, the additional error
statement will be executed
Changes to be committed:
new file: mysql-test/include/force_restart.inc
new file: mysql-test/include/wait_condition_with_debug.inc
modified: mysql-test/mysql-test-run.pl
modified: mysql-test/suite/galera/disabled.def
modified: mysql-test/suite/galera/r/MW-336.result
modified: mysql-test/suite/galera/r/galera_kill_applier.result
modified: mysql-test/suite/galera/r/galera_var_slave_threads.result
new file: mysql-test/suite/galera/t/MW-336.cnf
modified: mysql-test/suite/galera/t/MW-336.test
modified: mysql-test/suite/galera/t/galera_kill_applier.test
modified: mysql-test/suite/galera/t/galera_parallel_autoinc_largetrx.test
modified: mysql-test/suite/galera/t/galera_parallel_autoinc_manytrx.test
modified: mysql-test/suite/galera/t/galera_var_slave_threads.test
modified: mysql-test/suite/wsrep/disabled.def
modified: mysql-test/suite/wsrep/r/variables.result
modified: mysql-test/suite/wsrep/t/variables.test
modified: sql/mysqld.cc
modified: sql/wsrep_mysqld.cc
modified: sql/wsrep_mysqld.h
modified: sql/wsrep_thd.cc
modified: sql/wsrep_var.cc
MDEV-17058: Test failure on wsrep.variables
MDEV-17060: Test failure on galera.galera_var_slave_threads
Fix incorrect calculation of increased applier (slave) threads.
Note that increase change takes effect "immediately" but we should
use proper wait condition to wait it. Reducing the number of
slave threads is not immediate as thread will only exit after a
replication event.
The value of wsrep_affected_rows were not reseted properly for
slave. Now we also wsrep_affected_rows in Xid_log_event::do_apply_event
also , apart from THD::cleanup_after_query().
Signed-off-by: Sachin Setiya <sachin.setiya@mariadb.com>
==== Description ====
Flashback can rollback the instances/databases/tables to an old snapshot.
It's implement on Server-Level by full image format binary logs (--binlog-row-image=FULL), so it supports all engines.
Currently, it’s a feature inside mysqlbinlog tool (with --flashback arguments).
Because the flashback binlog events will store in the memory, you should check if there is enough memory in your machine.
==== New Arguments to mysqlbinlog ====
--flashback (-B)
It will let mysqlbinlog to work on FLASHBACK mode.
==== New Arguments to mysqld ====
--flashback
Setup the server to use flashback. This enables binary log in row mode
and will enable extra logging for DDL's needed by flashback feature
==== Example ====
I have a table "t" in database "test", we can compare the output with "--flashback" and without.
#client/mysqlbinlog /data/mysqldata_10.0/binlog/mysql-bin.000001 -vv -d test -T t --start-datetime="2013-03-27 14:54:00" > /tmp/1.sql
#client/mysqlbinlog /data/mysqldata_10.0/binlog/mysql-bin.000001 -vv -d test -T t --start-datetime="2013-03-27 14:54:00" -B > /tmp/2.sql
Then, importing the output flashback file (/tmp/2.log), it can flashback your database/table to the special time (--start-datetime).
And if you know the exact postion, "--start-postion" is also works, mysqlbinlog will output the flashback logs that can flashback to "--start-postion" position.
==== Implement ====
1. As we know, if binlog_format is ROW (binlog-row-image=FULL in 10.1 and later), all columns value are store in the row event, so we can get the data before mis-operation.
2. Just do following things:
2.1 Change Event Type, INSERT->DELETE, DELETE->INSERT.
For example:
INSERT INTO t VALUES (...) ---> DELETE FROM t WHERE ...
DELETE FROM t ... ---> INSERT INTO t VALUES (...)
2.2 For Update_Event, swapping the SET part and WHERE part.
For example:
UPDATE t SET cols1 = vals1 WHERE cols2 = vals2
--->
UPDATE t SET cols2 = vals2 WHERE cols1 = vals1
2.3 For Multi-Rows Event, reverse the rows sequence, from the last row to the first row.
For example:
DELETE FROM t WHERE id=1; DELETE FROM t WHERE id=2; ...; DELETE FROM t WHERE id=n;
--->
DELETE FROM t WHERE id=n; ...; DELETE FROM t WHERE id=2; DELETE FROM t WHERE id=1;
2.4 Output those events from the last one to the first one which mis-operation happened.
For example:
In CTAS, handlers get registered under statement transaction
(st_transactions::stmt), while ha_fake_trx_id(), used by CTAS,
looked under standard transaction (st_transactions::all) for
registered handlers, and thus it failed to grab a fake transaction
ID. As a result, with no valid transaction ID, wsrep commit failed
with an error.
ha_fake_trx_id() now looks for handlers registered under 'stmt'
in case 'all' is empty. Also modified the logic to print warning
only once if none of the registered handlers have fake_trx_id.
On wsrep_cluster_address update, node restarts the replication
and attempts to connect to the new address. In this process it
makes a call to wsrep provider's connect API, which could lead
to segfault if wsrep provider is not loaded (wsrep_on=OFF).
Fixed by making sure that it proceeds only if a provider is
loaded.
Added a SESSION-only system variable "wsrep_dirty_reads" to allow SELECT
queries to pass even when the node is not prepared to accept queries
(wsrep_ready=OFF). Added a test case.
When wsrep is enabled, an md5 hash of the entire row is calculated
for tables with no PK. It, however segfaulted as the md5 context
object was not properly constructed.
Fixed by ensuring that the YaSSL's context object gets constructed
explicitly at the specified pre-allocated location (placement)
before its used.
Added a test case.
Do not allow server to start if binlog_format is set
to a format other than ROW. Also restrict the change
of GLOBAL/SESSION binlog_format value at runtime.
Do not allow server to start if binlog_format is set
to a format other than ROW. Also restrict the change
of GLOBAL/SESSION binlog_format value at runtime.
