Mariadb in docker mariadb:lts

[nikkilocke]

I am switching my dotnet code from using mysql to mariadb.
I dumped my mysql database.
I created a new docker container based on mariadb:lts
I loaded my database.
I fired up my dotnet app, and immediately got an exception

MySql.Data.MySqlClient.SchemaProvider.GetIndexesAsync System.InvalidCastException: Unable to cast object of type 'System.Int64' to type 'System.UInt32'

The full stack trace is:

webapp-1     | Unhandled exception. System.InvalidCastException: Unable to cast object of type 'System.Int64' to type 'System.UInt32'.
webapp-1     |    at MySql.Data.MySqlClient.SchemaProvider.GetIndexesAsync(String[] restrictions, Boolean execAsync, CancellationToken cancellationToken)
webapp-1     |    at MySql.Data.MySqlClient.SchemaProvider.GetSchemaInternalAsync(String collection, String[] restrictions, Boolean execAsync, CancellationToken cancellationToken)
webapp-1     |    at MySql.Data.MySqlClient.ISSchemaProvider.GetSchemaInternalAsync(String collection, String[] restrictions, Boolean execAsync, CancellationToken cancellationToken)
webapp-1     |    at MySql.Data.MySqlClient.SchemaProvider.GetSchemaAsync(String collection, String[] restrictions, Boolean execAsync, CancellationToken cancellationToken)
webapp-1     |    at MySql.Data.MySqlClient.MySqlConnection.GetSchemaAsync(Boolean execAsync, String collectionName, String[] restrictionValues, CancellationToken cancellationToken)
webapp-1     |    at MySql.Data.MySqlClient.MySqlConnection.GetSchema(String collectionName)
webapp-1     |    at CodeFirstWebFramework.MySqlDatabase.Tables()
webapp-1     |    at CodeFirstWebFramework.Database.Upgrade()
webapp-1     |    at CodeFirstWebFramework.WebServer.registerServer(ServerConfig server)
webapp-1     |    at CodeFirstWebFramework.WebServer..ctor()
webapp-1     |    at BasecampGateway.Program.Main(String[] args) in /builds/nikki/basecampgateway/BasecampGateway/Program.cs:line 56
database-1   | 2024-09-03 14:17:00 3 [Warning] Aborted connection 3 to db: 'BasecampGateway' user: 'BasecampGateway' host: '172.16.98.3' (Got an error reading communication packets)
webapp-1     | Aborted

webapp-1 is the dotnet program, database-1 is the mariadb database.

[nikkilocke]

I suspect the issue may be here, in MySQL.Data/src/SchemaProvider.cs:296

        foreach (MySqlSchemaRow index in indexes.Rows)
        {
          if (1 != (connection.driver.Version.isAtLeast(8, 0, 1) ?
            (uint)index["SEQ_IN_INDEX"] :
            (long)index["SEQ_IN_INDEX"]))
            continue;

It seems a totally unnecessary conditional - why not always cast it to a long (if that works), or even use ToString and compare it to "1"?

I guess I should report this to the mysql-connector-net repo?

[grooverdan]

Thanks for tracing it down.

Yes, its a bit odd an implementation. I can see why the size was reduced, the number of elements in a index is limited, 32 in MariaDB and I haven't tested in MySQL, but 3072 bytes would impose a limit of that number. I'm not sure a mysql-connector-net bug report would achieve much, they have indicated they don't care about MariaDB compatibility, so if you do, emphasise some non-MariaDB improvements by the change.

https://github.com/mysql-net/MySqlConnector is an alternate and supports MariaDB as a server.

I've raised this a potential change in MariaDB to reduce the size of this return value for compatibility - https://jira.mariadb.org/browse/MDEV-34864. I've written a patch MariaDB/server#3498. If you'd like a container version for testing let me know.

[nikkilocke]

It might be a good idea to produce a nuget package called Data.Mariadb if you aren't going to be MySql compatible any more. Or tweak the version number that the Data.MySql package is checking. I did, eventually, find the mariadb equivalent, but only by a wider Web search.

…

On Wed, 4 Sept 2024, 00:18 Daniel Black, ***@***.***> wrote: Thanks for tracing it down. Yes, its a bit odd an implementation. I can see why the size was reduced, the number of elements in a index is limited, 32 in MariaDB and I haven't tested in MySQL, but 3072 bytes would impose a limit of that number. I'm not sure a mysql-connector-net would achieve much, they have indicated they don't care about MariaDB compatibility, so if you do, emphasise some non-MariaDB compatibility requirements. https://github.com/mysql-net/MySqlConnector is an alternate and supports MariaDB as a server. I've raised this a potential change in MariaDB to reduce the size of this return value for compatibility - https://jira.mariadb.org/browse/MDEV-34864. — Reply to this email directly, view it on GitHub <#613 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAFG76NW7RTVTHU56VM63KLZUY7U5AVCNFSM6AAAAABNSIDOY6VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDGMRXGYYTAOBYGE> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[grooverdan]

Per https://jira.mariadb.org/browse/MDEV-34864 - a server change was made to resolve this incompatibility.

[nikkilocke]

Thanks Daniel. Has this fix gone into the lts docker image? I tried to switch to using SqlConnector, but it does not support the "Foreign Key Columns" or "ViewColumns" collections. I have sort of worked round that. I am going to report the shortcomings of that package on their GitHub. Regards, Nikki

…

On Wed, 4 Sept 2024 at 09:38, Daniel Black ***@***.***> wrote: Per https://jira.mariadb.org/browse/MDEV-34864 - a server change was made to resolve this incompatibility. — Reply to this email directly, view it on GitHub <#613 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAFG76KLPRFHBVP3BWLSNXTZU3BHJAVCNFSM6AAAAABNSIDOY6VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDGMRYGI2TMNJUGA> . You are receiving this because you authored the thread.Message ID: ***@***.***>

-- Nikki Locke, Trumphurst Ltd. PC & Unix consultancy & programming http://www.trumphurst.com/

[iangilfillan]

The fix will be applied to the upcoming Q4 set of releases. You can view the estimated release dates on https://jira.mariadb.org.