[MDEV-31746] Problems with tx_isolation after MDEV-21921 - Jira

Details

Type: Bug
Status: Closed (View Workflow)
Priority: Blocker
Resolution: Fixed
Affects Version/s: 11.1.1
Fix Version/s: 11.1.1
Component/s: Variables
Labels:
None

Description

~~MDEV-21921~~ breaks almost all connectors, that read and track tx_isolation value - probably all except only C/C,. We can fix connectors to live with it, that is pretty easy fix. But if it breaks connectors it can also break applications. C/C applications for example.

tx_isolation isn't full alias of tranasaction_isolation - client can't set it and can't track it. It's a bit too radical and/or to fast deprecation to my taste.

If we try to set it directly, we don't get an error, we get warning about deprecation, but the value is not changed.

MariaDB [test]> select @@tx_isolation;

+----------------+

| @@tx_isolation |

+----------------+

| READ-COMMITTED |

+----------------+

1 row in set (0.000 sec)

MariaDB [test]> set @@tx_isolation='REPEATABLE-READ';

Query OK, 0 rows affected, 1 warning (0.000 sec)

MariaDB [test]> show warnings;

+---------+------+----------------------------------------------------------------------------------------------------------------------+

| Level   | Code | Message                                                                                                              |

+---------+------+----------------------------------------------------------------------------------------------------------------------+

| Warning | 1287 | '@@tx_isolation' is deprecated and will be removed in a future release. Please use '@@transaction_isolation' instead |

+---------+------+----------------------------------------------------------------------------------------------------------------------+

1 row in set (0.000 sec)

MariaDB [test]> select @@tx_isolation;

+----------------+

| @@tx_isolation |

+----------------+

| READ-COMMITTED |

+----------------+

1 row in set (0.000 sec)

So, the query hasn't really succeeded, but we don't get the error

If we attempt to track tx_isolation, the result is even worse - no error, no warning, the value is set, but the variable is not tracked.

Server version: 11.1.1-MariaDB mariadb.org binary distribution

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MariaDB [test]> SET session_track_system_variables='tx_isolation';

Query OK, 0 rows affected (0.000 sec)

MariaDB [test]> show variables like "%track%";

+--------------------------------+--------------+

| Variable_name                  | Value        |

+--------------------------------+--------------+

| session_track_schema           | ON           |

| session_track_state_change     | OFF          |

| session_track_system_variables | tx_isolation |

| session_track_transaction_info | OFF          |

+--------------------------------+--------------+

4 rows in set (0.001 sec)

We verified that with various connectors, that the variable is not actually tracked.
So, the very least that should be done is bringing some consistency - remove tx_isolation from session_track_system_variables and return warning about its deprecation the way it's done with setting of the tx_isolation.

But I think we should consider something more than that up to making it work as before, but with warnings of deprecation. Nobody reads warnings, so maybe something in between would be better - make tracking of tx_isolation work, but leave setting of it not working(it's probably not the blessed way of changing of isolation level anyway). Maybe even make it return error- it makes more sense for me.

Attachments

Issue Links

is caused by

MDEV-21921 Make transaction_isolation into a system variable

Closed

relates to

MDEV-29629 Session state tracking does not track variable changes via aliases

Closed

MDEV-31751 SET @@tx_isolation=X behaves like SET TRANSACATION ISOLATION LEVEL X instead of SET SESSSION tx_isolation=X

In Review

MDBF-952 Protocol regression testing for the server

Open

Activity

Ascending order - Click to sort in descending order

Lawrin Novitsky created issue - 2023-07-19 20:57

Lawrin Novitsky made changes - 2023-07-19 21:04

Field	Original Value	New Value
Description	~~MDEV-21921~~ also breaks almost all connectors, that read and track tx_isolation value - probably all except only C/C,. We can fix connectors to live with it, that is pretty easy fix. But if it breaks connectors it can also break applications. C/C applications for example. tx_isolation isn't full alias of tranasaction_isolation - client can't set it and can't track it. It's a bit too radical and/or to fast deprecation to my taste. If we try to set it directly, we don't get an error, we get warning about deprecation, but the value is not changed. {code:java} MariaDB [test]> select @@tx_isolation; +----------------+ \| @@tx_isolation \| +----------------+ \| READ-COMMITTED \| +----------------+ 1 row in set (0.000 sec) MariaDB [test]> set @@tx_isolation='REPEATABLE-READ'; Query OK, 0 rows affected, 1 warning (0.000 sec) MariaDB [test]> show warnings; +---------+------+----------------------------------------------------------------------------------------------------------------------+ \| Level \| Code \| Message \| +---------+------+----------------------------------------------------------------------------------------------------------------------+ \| Warning \| 1287 \| '@@tx_isolation' is deprecated and will be removed in a future release. Please use '@@transaction_isolation' instead \| +---------+------+----------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.000 sec) MariaDB [test]> select @@tx_isolation; +----------------+ \| @@tx_isolation \| +----------------+ \| READ-COMMITTED \| +----------------+ 1 row in set (0.000 sec) {code} So, the query hasn't really succeeded, but we don't get the error If we attempt to track tx_isolation, the result is even worse - no error, no warning, the value is set, but the variable is not tracked. {code:java} Server version: 11.1.1-MariaDB mariadb.org binary distribution Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. MariaDB [test]> SET session_track_system_variables='tx_isolation'; Query OK, 0 rows affected (0.000 sec) MariaDB [test]> show variables like "%track%"; +--------------------------------+--------------+ \| Variable_name \| Value \| +--------------------------------+--------------+ \| session_track_schema \| ON \| \| session_track_state_change \| OFF \| \| session_track_system_variables \| tx_isolation \| \| session_track_transaction_info \| OFF \| +--------------------------------+--------------+ 4 rows in set (0.001 sec) {code} We verified that with various connectors, that the variable is not actually tracked. So, the very least that should be done is bringing some consistency - remove tx_isolation from session_track_system_variables and return warning about its deprecation the way it's done with setting of the tx_isolation. But I think we should consider something more than that up to making it work as before, but with warnings of deprecation. Nobody reads warnings, so maybe something in between would be better - still tracking of tx_isolation, but setting leave not working(it's probably not the blessed way of changing of isolation level anyway). Maybe even make it return error- it makes more sense for me.	~~MDEV-21921~~ breaks almost all connectors, that read and track tx_isolation value - probably all except only C/C,. We can fix connectors to live with it, that is pretty easy fix. But if it breaks connectors it can also break applications. C/C applications for example. tx_isolation isn't full alias of tranasaction_isolation - client can't set it and can't track it. It's a bit too radical and/or to fast deprecation to my taste. If we try to set it directly, we don't get an error, we get warning about deprecation, but the value is not changed. {code:java} MariaDB [test]> select @@tx_isolation; +----------------+ \| @@tx_isolation \| +----------------+ \| READ-COMMITTED \| +----------------+ 1 row in set (0.000 sec) MariaDB [test]> set @@tx_isolation='REPEATABLE-READ'; Query OK, 0 rows affected, 1 warning (0.000 sec) MariaDB [test]> show warnings; +---------+------+----------------------------------------------------------------------------------------------------------------------+ \| Level \| Code \| Message \| +---------+------+----------------------------------------------------------------------------------------------------------------------+ \| Warning \| 1287 \| '@@tx_isolation' is deprecated and will be removed in a future release. Please use '@@transaction_isolation' instead \| +---------+------+----------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.000 sec) MariaDB [test]> select @@tx_isolation; +----------------+ \| @@tx_isolation \| +----------------+ \| READ-COMMITTED \| +----------------+ 1 row in set (0.000 sec) {code} So, the query hasn't really succeeded, but we don't get the error If we attempt to track tx_isolation, the result is even worse - no error, no warning, the value is set, but the variable is not tracked. {code:java} Server version: 11.1.1-MariaDB mariadb.org binary distribution Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. MariaDB [test]> SET session_track_system_variables='tx_isolation'; Query OK, 0 rows affected (0.000 sec) MariaDB [test]> show variables like "%track%"; +--------------------------------+--------------+ \| Variable_name \| Value \| +--------------------------------+--------------+ \| session_track_schema \| ON \| \| session_track_state_change \| OFF \| \| session_track_system_variables \| tx_isolation \| \| session_track_transaction_info \| OFF \| +--------------------------------+--------------+ 4 rows in set (0.001 sec) {code} We verified that with various connectors, that the variable is not actually tracked. So, the very least that should be done is bringing some consistency - remove tx_isolation from session_track_system_variables and return warning about its deprecation the way it's done with setting of the tx_isolation. But I think we should consider something more than that up to making it work as before, but with warnings of deprecation. Nobody reads warnings, so maybe something in between would be better - make tracking of tx_isolation work, but leave setting of it not working(it's probably not the blessed way of changing of isolation level anyway). Maybe even make it return error- it makes more sense for me.

Sergei Golubchik made changes - 2023-07-19 21:42

Link

This issue is caused by ~~MDEV-21921~~ [ ~~MDEV-21921~~ ]

Sergei Golubchik made changes - 2023-07-19 21:43

Fix Version/s

11.1.2 [ 28921 ]

Sergei Golubchik made changes - 2023-07-19 21:44

Fix Version/s		11.1 [ 28549 ]
Fix Version/s	11.1.2 [ 28921 ]

Sergei Golubchik made changes - 2023-07-19 21:44

Priority

Major [ 3 ]

Blocker [ 1 ]

Sergei Golubchik made changes - 2023-07-19 21:44

Assignee

Daniel Black [ danblack ]

Vladislav Vaintroub made changes - 2023-07-19 23:42

Link

This issue relates to MDEV-15148 [ MDEV-15148 ]

Daniel Black made changes - 2023-07-20 00:16

Status

Open [ 1 ]

In Progress [ 3 ]

Daniel Black made changes - 2023-07-20 02:19

Status

In Progress [ 3 ]

Needs Feedback [ 10501 ]

Daniel Black made changes - 2023-07-20 02:20

Priority

Blocker [ 1 ]

Critical [ 2 ]

Daniel Black made changes - 2023-07-20 03:21

Link

This issue relates to ~~MDEV-29629~~ [ ~~MDEV-29629~~ ]

Sergei Golubchik made changes - 2023-07-20 08:04

Priority

Critical [ 2 ]

Blocker [ 1 ]

Daniel Black made changes - 2023-07-20 09:23

Link

This issue relates to MDEV-31751 [ MDEV-31751 ]

Daniel Black made changes - 2023-07-20 09:27

Status

Needs Feedback [ 10501 ]

Open [ 1 ]

Daniel Black made changes - 2023-07-21 06:59

Status

Open [ 1 ]

In Progress [ 3 ]

Daniel Black made changes - 2023-07-21 06:59

Assignee	Daniel Black [ danblack ]	Sergei Golubchik [ serg ]
Status	In Progress [ 3 ]	In Review [ 10002 ]

Daniel Black made changes - 2023-07-21 11:57

Link

This issue is blocked by ~~MDBF-577~~ [ ~~MDBF-577~~ ]

Sergei Golubchik made changes - 2023-07-21 12:57

Assignee	Sergei Golubchik [ serg ]	Daniel Black [ danblack ]
Status	In Review [ 10002 ]	Stalled [ 10000 ]

Daniel Black made changes - 2023-07-24 01:33

Link

This issue is blocked by ~~MDBF-577~~ [ ~~MDBF-577~~ ]

Daniel Black made changes - 2023-07-27 00:06

Assignee	Daniel Black [ danblack ]	Sergei Golubchik [ serg ]
Status	Stalled [ 10000 ]	In Review [ 10002 ]

Sergei Golubchik made changes - 2023-08-03 16:03

Status

In Review [ 10002 ]

In Testing [ 10301 ]

Sergei Golubchik made changes - 2023-08-10 08:01

Fix Version/s		11.1.1 [ 28704 ]
Fix Version/s	11.1 [ 28549 ]
Resolution		Fixed [ 1 ]
Status	In Testing [ 10301 ]	Closed [ 6 ]

People

Assignee:: Sergei Golubchik

Reporter:: Lawrin Novitsky

Votes:: 1 Vote for this issue

Watchers:: 8 Start watching this issue

Dates

Created:: 2023-07-19 20:57

Updated:: 2023-10-10 23:47

Resolved:: 2023-08-10 08:01

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