[8.x] Add support for MariaDB to skip locked rows with the database queue driver

[antoniopaisfernandes]

As documented in https://mariadb.com/kb/en/select/#skip-locked since MariaDB 10.6 there is support for skipping locked rows when fetching from the database.

This change adds support to it.

[RensBruil]

This update actually crashed our queue workers. We updated the framework/laravel version from v8.64.0 to v8.67.0 and suddenly all of our queue workers conflicted because of the FOR UPDATE SKIP LOCKED. Our MariaDB version is: 10.3.31-MariaDB-log - MariaDB Server. Rolling back to v8.64.0 solved the issue.

[antoniopaisfernandes]

Can you please show your result for:

$databaseEngine = \DB::getPdo()->getAttribute(PDO::ATTR_DRIVER_NAME);
$databaseVersion = \DB::getPdo()->getAttribute(PDO::ATTR_SERVER_VERSION);

echo version_compare($databaseVersion, '8.0.1', '>='));
echo strpos($databaseVersion, 'MariaDB');
echo version_compare(\Str::after($databaseVersion, '-'), '10.6.0', '>=');

Thanks

[RensBruil]

It just returns 18 if I run your script. The 3 echo's are:
version_compare($databaseVersion, '8.0.1', '>=') = true;
strpos($databaseVersion, 'MariaDB'); = 8
version_compare(\Str::after($databaseVersion, '-'), '10.6.0', '>='); = false

[xavi7th]

I can confirm this same issues. I have been debugging for the past 3 days. I only just reaslised that the issue started after I upgraded.

I am also on version 10.3.31-MariaDB-log-cll-lve - MariaDB Server and Laravel 8.67.

Kindly look into it

[antoniopaisfernandes]

Will refactor the conditional.

[antoniopaisfernandes]

if (($databaseEngine === 'mysql' && ! strpos($databaseVersion, 'MariaDB') && version_compare($databaseVersion, '8.0.1', '>=')) ||
    (strpos($databaseVersion, 'MariaDB') && version_compare(Str::after($databaseVersion, '5.5.5-'), '10.6.0', '>=')) ||
    ($databaseEngine === 'pgsql' && version_compare($databaseVersion, '9.5', '>='))) {
    return 'FOR UPDATE SKIP LOCKED';
}

[thotam]

shed our queue workers. We updated the framework/laravel version from v8.64.0 to v8.67.0 and suddenly all of our queue workers conflicted because of the FOR UPDATE SKIP LOCKED. Our MariaDB version is: 10.3.31-MariaDB-log - MariaDB Server. Rolling back to v8.64.0 solved the issue.

Same me

[coziboy]

This update actually crashed our queue workers. We updated the framework/laravel version from v8.64.0 to v8.67.0 and suddenly all of our queue workers conflicted because of the FOR UPDATE SKIP LOCKED. Our MariaDB version is: 10.3.31-MariaDB-log - MariaDB Server. Rolling back to v8.64.0 solved the issue.

same here

[taylorotwell]

Revert it all.

[taylorotwell]

@antoniopaisfernandes please test your changes. I will be merging nothing else in this regard for a while.

[antoniopaisfernandes]

@taylorotwell Sorry for the mess I put you in :(

I'll find out more scenarios and how to improve the code.

[driesvints]

@antoniopaisfernandes think it's best that we leave this be for now.

[antoniopaisfernandes]

Thank you and apologies.

[driesvints]

I did a new attempt for this at #39396

[mxts]

I just feel this is easier to read.. and change

        if (Str::of($databaseVersion)->contains('MariaDB')) {
            $databaseEngine = 'MariaDB';
            $databaseVersion = Str::of($databaseVersion)->match("/\d+\.\d+\.\d+/");
        }

        if (($databaseEngine === 'mysql' && version_compare($databaseVersion, '8.0.1', '>=')) ||
            ($databaseEngine === 'MariaDB' && version_compare($databaseVersion, '10.6.0', '>=')) ||
            ($databaseEngine === 'pgsql' && version_compare($databaseVersion, '9.5', '>='))) {
            $result = 'FOR UPDATE SKIP LOCKED';
        }

[driesvints]

Thanks @mxts, I added that suggestion, that looks indeed better. The regex wasn't correct though as it won't strip the 5.5.5- part.

[driesvints]

Btw I'd greatly appreciate it if you all could try out #39396 to see if it passes for your systems.

@antoniopaisfernandes @RensBruil @xavi7th @thotam @coziboy

[antoniopaisfernandes]

@driesvints Thank you so much for your care! 🦸‍♂️

With vanilla MariaDB 10.5:

211028 18:34:58     20 Connect  root@localhost on testapp using TCP/IP
                    20 Query    use `testapp`
                    20 Prepare  set names 'utf8mb4' collate 'utf8mb4_unicode_ci'
                    20 Execute  set names 'utf8mb4' collate 'utf8mb4_unicode_ci'
                    20 Close stmt
                    20 Prepare  set session sql_mode='ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION'
                    20 Execute  set session sql_mode='ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION'
                    20 Close stmt
                    20 Query    START TRANSACTION
                    20 Prepare  select * from `jobs` where `queue` = ? and ((`reserved_at` is null and `available_at` <= ?) or (`reserved_at` <= ?)) order by `id` asc limit 1 for update
                    20 Execute  select * from `jobs` where `queue` = 'default' and ((`reserved_at` is null and `available_at` <= 1635446098) or (`reserved_at` <= 1635446008)) order by `id` asc limit 1 for update
                    20 Close stmt
                    20 Query    COMMIT

With 10.6:

Tcp port: 3306  Unix socket: /var/lib/mysql/mysql.sock
Time                Id Command  Argument
211028 18:38:47     21 Connect  root@localhost on testapp using TCP/IP
                    21 Query    use `testapp`
                    21 Prepare  set names 'utf8mb4' collate 'utf8mb4_unicode_ci'
                    21 Execute  set names 'utf8mb4' collate 'utf8mb4_unicode_ci'
                    21 Close stmt
                    21 Prepare  set session sql_mode='ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION'
                    21 Execute  set session sql_mode='ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION'
                    21 Close stmt
                    21 Query    START TRANSACTION
                    21 Prepare  select * from `jobs` where `queue` = ? and ((`reserved_at` is null and `available_at` <= ?) or (`reserved_at` <= ?)) order by `id` asc limit 1 FOR UPDATE SKIP LOCKED
                    21 Execute  select * from `jobs` where `queue` = 'default' and ((`reserved_at` is null and `available_at` <= 1635446327) or (`reserved_at` <= 1635446237)) order by `id` asc limit 1 FOR UPDATE SKIP LOCKED
                    21 Close stmt
                    21 Query    COMMIT

No errors running the workers! 🥳

[mxts]

@antoniopaisfernandes

Digress a bit here, how did you all manage to find the issue?

• I only looked into it because emails were not being dispatched.
• Running php artisan queue:work did not produce any exceptions and did not run any jobs
• It took me quite a bit of debugging because I wasn't closely monitoring my development honeybadger.

What I mean is, is there a "best" way to look out for/catch such exceptions?

[antoniopaisfernandes]

@mxts For the test I just activated MariaDB logging SET GLOBAL general_log=1 and started a worker with the Laravel framework at the commit @driesvints made.

As for being aware of problems in the runners, our choice was Sentry https://sentry.io/for/laravel/ but there are a lot of solutions for it.

[bilogic]

@antoniopaisfernandes thanks I was hoping for something to appear when I run queue:work