mariadb/mysql-test
Brandon Nesterenko 063f4ac25e MDEV-30619: Parallel Slave SQL Thread Can Update Seconds_Behind_Master with Active Workers
MDEV-31749 sporadic assert in MDEV-30619 new test

If the workers of a parallel replica are busy (potentially with long
queues), but the SQL thread has no events left to distribute (so it
goes idle), then the next event that comes from the primary will
update mi->last_master_timestamp with its timestamp, even if the
workers have not yet finished.

This patch changes the parallel replica logic which updates
last_master_timestamp after idling from using solely sql_thread_caught_up
(added in MDEV-29639) to using the latter with rli queued/dequeued
event counters.
That is, if  the queued count is equal to the dequeued count, it
means all events have been processed and the replica is considered
idle when the driver thread has also distributed all events.

Low level details of the commit include
- to make a more generalized test for Seconds_Behind_Master on
  the parallel replica, rpl_delayed_parallel_slave_sbm.test
  is renamed to rpl_parallel_sbm.test for this purpose.
- pause_sql_thread_on_next_event usage was removed
  with the MDEV-30619 fixes. Rather than remove it, we adapt it
  to the needs of this test case
- added test case to cover SBM spike of relay log read and LMT
  update that was fixed by MDEV-29639
- rpl_seconds_behind_master_spike.test is made to use
  the negate_clock_diff_with_master debug eval.

Reviewed By:
============
Andrei Elkin <andrei.elkin@mariadb.com>
2023-07-25 16:36:14 +03:00
..
collections
include
lib
main
std_data
suite MDEV-30619: Parallel Slave SQL Thread Can Update Seconds_Behind_Master with Active Workers 2023-07-25 16:36:14 +03:00
CMakeLists.txt
dgcov.pl
mtr.out-of-source
mysql-stress-test.pl
mysql-test-run.pl
purify.supp
README
README-gcov
README.stress
suite.pm
unstable-tests
valgrind.supp

This directory contains test suites for the MariaDB server. To run
currently existing test cases, execute ./mysql-test-run in this directory.

Some tests are known to fail on some platforms or be otherwise unreliable.
The file "unstable-tests" contains the list of such tests along with
a comment for every test.
To exclude them from the test run, execute
  # ./mysql-test-run --skip-test-list=unstable-tests

In general you do not have to have to do "make install", and you can have
a co-existing MariaDB installation, the tests will not conflict with it.
To run the tests in a source directory, you must do "make" first.

In Red Hat distributions, you should run the script as user "mysql".
The user is created with nologin shell, so the best bet is something like
  # su -
  # cd /usr/share/mysql-test
  # su -s /bin/bash mysql -c "./mysql-test-run --skip-test-list=unstable-tests"

This will use the installed MariaDB executables, but will run a private
copy of the server process (using data files within /usr/share/mysql-test),
so you need not start the mysqld service beforehand.

You can omit --skip-test-list option if you want to check whether
the listed failures occur for you.

To clean up afterwards, remove the created "var" subdirectory, e.g.
  # su -s /bin/bash - mysql -c "rm -rf /usr/share/mysql-test/var"

If one or more tests fail on your system on reasons other than listed
in lists of unstable tests, please read the following manual section
for instructions on how to report the problem:

https://mariadb.com/kb/en/reporting-bugs

If you want to use an already running MySQL server for specific tests,
use the --extern option to mysql-test-run. Please note that in this mode,
you are expected to provide names of the tests to run.

For example, here is the command to run the "alias" and "analyze" tests
with an external server:

  # mysql-test-run --extern socket=/tmp/mysql.sock alias analyze

To match your setup, you might need to provide other relevant options.

With no test names on the command line, mysql-test-run will attempt
to execute the default set of tests, which will certainly fail, because
many tests cannot run with an external server (they need to control the
options with which the server is started, restart the server during
execution, etc.)

You can create your own test cases. To create a test case, create a new
file in the main subdirectory using a text editor. The file should have a .test
extension. For example:

  # xemacs t/test_case_name.test

In the file, put a set of SQL statements that create some tables,
load test data, and run some queries to manipulate it.

Your test should begin by dropping the tables you are going to create and
end by dropping them again. This ensures that you can run the test over
and over again.

If you are using mysqltest commands in your test case, you should create
the result file as follows:

  # mysql-test-run --record test_case_name

  or

  # mysqltest --record < t/test_case_name.test

If you only have a simple test case consisting of SQL statements and
comments, you can create the result file in one of the following ways:

  # mysql-test-run --record test_case_name

  # mysql test < t/test_case_name.test > r/test_case_name.result

  # mysqltest --record --database test --result-file=r/test_case_name.result < t/test_case_name.test

When this is done, take a look at r/test_case_name.result.
If the result is incorrect, you have found a bug. In this case, you should
edit the test result to the correct results so that we can verify that
the bug is corrected in future releases.

If you want to submit your test case you can send it 
to maria-developers@lists.launchpad.net or attach it to a bug report on
http://mariadb.org/jira/.

If the test case is really big or if it contains 'not public' data,
then put your .test file and .result file(s) into a tar.gz archive,
add a README that explains the problem, ftp the archive to
ftp://ftp.askmonty.org/private and submit a report to
http://mariadb.org/jira about it.

The latest information about mysql-test-run can be found at:
https://mariadb.com/kb/en/mariadb/mysqltest/

If you want to create .rdiff files, check
https://mariadb.com/kb/en/mariadb/mysql-test-auxiliary-files/