Improve error messages

[killme2008]

What type of enhancement is this?

API improvement

What does the enhancement do?

The error messages in GreptimeDB have some issues:

• Errors from DataFusion always appear as internal errors, which can be confusing and unhelpful for users.
• The MySQL protocol consistently returns an internal error type: https://github.com/GreptimeTeam/greptimedb/blob/da0c8402619134d455242bd5c16e16a3b3955994/src/servers/src/mysql/writer.rs#L233
• A similar problem exists in PostgreSQL: https://github.com/GreptimeTeam/greptimedb/blob/da0c8402619134d455242bd5c16e16a3b3955994/src/servers/src/postgres/handler.rs#L99
• Errors around timeout #3800
• Some errors are mistakenly categorized as Internal or Unknown, causing the error message to not display correctly.
• If you have any other issues that you are aware of, please feel free to comment on them. An effective system should offer clear information when errors occur.

Implementation challenges

• [x] Correct all the error types that are wrongly categorized into Internal or Unknown.
• [ ] Returns the correct errors from DataFusion.
  • Proposed by @shuiyisong

    Add a special tag in front of the DataFusion error string, like "__gterror:",  
    then serialize the original error information into it; if we detect this type of error message outside, 
    deserialize it back to our original error.

• [x] Write the proper error kind for MySQL.
  • Mapping StatusCode to ErrorKind
  • https://greptimedb.rs/common_error/status_code/enum.StatusCode.html
  • https://docs.rs/opensrv-mysql/latest/opensrv_mysql/enum.ErrorKind.html
• [x] Write the proper error code for PostgreSQL.
  • Mapping StatusCode to PostgreSQL error codes
  • https://greptimedb.rs/common_error/status_code/enum.StatusCode.html
  • https://www.postgresql.org/docs/current/errcodes-appendix.html

No response

[evenyag]

Returns the correct errors from DataFusion.

As mentioned in https://github.com/GreptimeTeam/greptimedb/pull/4362#discussion_r1677778154, maybe we can wrap the error into a BoxedError before casting to the DataFusion error. Then we can always downcast the error into our BoxedError. cc @shuiyisong

[leaf-potato]

I want to have a try for PostgreSQL.

[killme2008]

I want to have a try for PostgreSQL.

Cool, thank you.

[leaf-potato]

@killme2008 I have a problem. Different from mysql crate, no type of PostgreSQL error codes found in pgwire crate. So in order to map StatusCode, I need to define enum PgWireErrorCode first?

enum PgWireErrorCode {
    EC_00000,
    EC_01000,
    ...
}

[killme2008]

@killme2008 I have a problem. Different from mysql crate, no type of PostgreSQL error codes found in pgwire crate. So in order to map StatusCode, I need to define enum PgWireErrorCode first?

enum PgWireErrorCode {
    EC_00000,
    EC_01000,
    ...
}

Yes, but i think you don't need to define all the pg error codes, but just the StatusCode needs.

https://greptimedb.rs/common_error/status_code/enum.StatusCode.html

[killme2008]

Or maybe a function like fn status_code_to_pg_error(status: StatusCode) -> &str is enough.