Example of the failure:
http://buildbot.askmonty.org/buildbot/builders/bld-p9-rhel7/builds/4417/steps/mtr/logs/stdio
```
main.mysqld--help 'unix' w17 [ fail ]
Test ended at 2020-06-20 18:51:45
CURRENT_TEST: main.mysqld--help
--- /opt/buildbot-slave/bld-p9-rhel7/build/mysql-test/main/mysqld--help.result 2020-06-20 16:06:49.903604179 +0300
+++ /opt/buildbot-slave/bld-p9-rhel7/build/mysql-test/main/mysqld--help.reject 2020-06-20 18:51:44.886766820 +0300
@@ -1797,10 +1797,10 @@
sync-relay-log-info 10000
sysdate-is-now FALSE
system-versioning-alter-history ERROR
-table-cache 421
+table-cache 2000
table-definition-cache 400
-table-open-cache 421
-table-open-cache-instances 1
+table-open-cache 2000
+table-open-cache-instances 8
tc-heuristic-recover OFF
tcp-keepalive-interval 0
tcp-keepalive-probes 0
mysqltest: Result length mismatch
```
mtr: table_open_cache_basic autosized:
Lets assume that >400 are available and that
we can set the result back to the start value.
All of these system variables are autosized and can
generate MTR output differences.
Closes#1527
This patch introduces support for the system variable eq_range_index_dive_limit
that existed in MySQL starting from 5.6. The variable sets a limit for
index dives into equality ranges. Index dives are performed by optimizer
to estimate the number of rows in range scans. Index dives usually provide
good estimate but they are pretty expensive. To estimate the number of rows
in equality ranges statistical data on indexes can be employed. Its usage gives
not so good estimates but it's cheap. So if the number of equality dives
required by an index scan exceeds the set limit no dives for equality
ranges are performed by the optimizer for this index.
As the new system variable is introduced in a stable version the default
value for it is set to a special value meaning there is no limit for the number
of index dives performed by the optimizer.
The patch partially uses the MySQL code for WL 5957
'Statistics-based Range optimization for many ranges'.
Also clarify which --{no-,}default* options, must be first.
Sample output:
$ client/mysql --help
client/mysql Ver 15.1 Distrib 5.5.59-MariaDB, for Linux (x86_64) using readline 5.1
Copyright (c) 2000, 2017, Oracle, MariaDB Corporation Ab and others.
Usage: client/mysql [OPTIONS] [database]
Default options are read from the following files in the given order:
/etc/my.cnf /etc/mysql/my.cnf ~/.my.cnf
The following groups are read: mysql client client-server client-mariadb
The following options may be given as the first argument:
--print-defaults Print the program argument list and exit.
--no-defaults Don't read default options from any option file.
The following specify which files/groups are read (specified before other options):
--defaults-file=# Only read default options from the given file #.
--defaults-extra-file=# Read this file after the global files are read.
--defaults-group-suffix=# Additionally read default groups with # appended as a suffix.
tests running from build directory:
TEST: print defaults ignored as not first
$ sql/mysqld --no-defaults --print-defaults --lc-messages-dir=${PWD}/sql/share
TEST: no startup occurs as --print-defaults specified
$ sql/mysqld --print-defaults --lc-messages-dir=${PWD}/sql/share
sql/mysqld would have been started with the following arguments:
--lc-messages-dir=/home/dan/repos/build-mariadb-5.5/sql/share
TEST: default args can't be anywhere
$ client/mysql --user=bob --defaults-file=/etc/my.cnf
client/mysql: unknown variable 'defaults-file=/etc/my.cnf'
$ client/mysql --user=bob --defaults-group-suffix=.group
client/mysql: unknown variable 'defaults-group-suffix=.group'
/etc/my.cnf:
[client-server.group]
socket=/var/lib/mysql-multi/group/mysqld.sock
user=bob
/etc/my.other.cnf:
socket=/var/lib/mysql-other/mysqld.sock
TEST: defaults file read and suffix also applied
$ client/mysql --defaults-file=/etc/my.other.cnf --defaults-group-suffix=.group
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql-other/mysqld.sock' (2)
TEST: defaults extra file
$ client/mysql --defaults-extra-file=/etc/my.other.cnf --defaults-group-suffix=.group
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql-other/mysqld.sock' (2)
MDEV--15609 engines/funcs.crash_manytables_number crashes with error 24
(too many open files)
MDEV-10286 Adjustment of table_open_cache according to system limits
does not work when open-files-limit option is provided
Fixed by adjusting tc_size downwards if there is not enough file
descriptors to use.
Other changes:
- Ensure that there is 30 (was 10) extra file descriptors for other usage
- Decrease TABLE_OPEN_CACHE_MIN to 200 as it's better to have a smaller
table cache than getting error 24
- Increase minimum of max_connections and table_open_cache from 1 to 10
as 1 is not usable for any real application, only for testing.
For running the Galera tests, the variable my_disable_leak_check
was set to true in order to avoid assertions due to memory leaks
at shutdown.
Some adjustments due to MDEV-13625 (merge InnoDB tests from MySQL 5.6)
were performed. The most notable behaviour changes from 10.0 and 10.1
are the following:
* innodb.innodb-table-online: adjustments for the DROP COLUMN
behaviour change (MDEV-11114, MDEV-13613)
* innodb.innodb-index-online-fk: the removal of a (1,NULL) record
from the result; originally removed in MySQL 5.7 in the
Oracle Bug #16244691 fix
377774689b
* innodb.create-index-debug: disabled due to MDEV-13680
(the MySQL Bug #77497 fix was not merged from 5.6 to 5.7.10)
* innodb.innodb-alter-autoinc: MariaDB 10.2 behaves like MySQL 5.6/5.7,
while MariaDB 10.0 and 10.1 assign different values when
auto_increment_increment or auto_increment_offset are used.
Also MySQL 5.6/5.7 exhibit different behaviour between
LGORITHM=INPLACE and ALGORITHM=COPY, so something needs to be tested
and fixed in both MariaDB 10.0 and 10.2.
* innodb.innodb-wl5980-alter: disabled because it would trigger an
InnoDB assertion failure (MDEV-13668 may need additional effort in 10.2)
- make re-bootstrap run with all extra options, not only InnoDB ones
- re-use previously created bootstrap.sql
- add --console
- fix debian patch to keep it applicable
- Added variable tmp_disk_table_size
- Added variable tmp_memory_table_size as an alias for tmp_table_size
- Changed internal variable tmp_table_size to tmp_memory_table_size
- create_info.data_file_length is now set with tmp_disk_table_size
- Fixed that Aria doesn't reset max_data_file_length for internal tables
- Added status flag if table is full so that we can detect this on next insert.
This ensures that the table is always 'correct', but we get the error one
row after the row that grow the table too big.
- Removed some mutex lock for internal temporary tables
==== 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:
Most notably, this includes MDEV-11623, which includes a fix and
an upgrade procedure for the InnoDB file format incompatibility
that is present in MariaDB Server 10.1.0 through 10.1.20.
In other words, this merge should address
MDEV-11202 InnoDB 10.1 -> 10.2 migration does not work
