[source-mssql] Syncs fail with invalid timeout string (works in 4.2.6)

[justbeez]

Connector Name

source-mssql

Connector Version

4.3.3

What step the error happened?

During the sync

Relevant information

Effectively when using newer versions, I can't sync to certain servers. I can run a connection check just fine, but then the sync fails to start and throws one of these two forms of the same error:

ERROR main i.a.c.AirbyteConnectorRunnable(run):38 Failed class io.airbyte.cdk.discover.DiscoverOperation operation execution. com.microsoft.sqlserver.jdbc.SQLServerException: The timeout 300;socketTimeout=0;cancelQueryTimeout=0 is not valid.

. . . or this one (which seems to happen on subsequent attempts):

ERROR Failing job: 923287, reason: Could not connect with provided configuration. Error: Message: The timeout 300;socketTimeout=0;cancelQueryTimeout=0 is not valid.

Regardless it appears that the issue is the timeout value being provided being malformed. I'm not certain if this is specific to SQL server version, as I've seen failures on several different connections to various third-party SQL servers (some of which I don't know the version of).

I've had to pin my connector version to 4.2.6 due to this issue, in which case the sync completes just fine.

Relevant log output

ERROR main i.a.c.AirbyteConnectorRunnable(run):38 Failed class io.airbyte.cdk.discover.DiscoverOperation operation execution. com.microsoft.sqlserver.jdbc.SQLServerException: The timeout 300;socketTimeout=0;cancelQueryTimeout=0 is not valid.

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Internal Tracking: https://github.com/airbytehq/oncall/issues/11187

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[devin-ai-integration]

Hi @justbeez, thank you for reporting this issue!

This looks like a regression introduced in the v4.3.x line, which migrated source-mssql from the legacy CDK to the new Bulk CDK architecture (starting with 4.3.0-rc.1). The error message indicates the JDBC connection string is being constructed with a malformed timeout value:

The timeout 300;socketTimeout=0;cancelQueryTimeout=0 is not valid.

It appears that multiple JDBC URL parameters are being concatenated into a single property value instead of being parsed as separate key-value pairs.

Initial Analysis

The new CDK constructs the JDBC connection differently from the old connector. In the old connector, JDBC URL parameters were likely appended directly to the MSSQL connection URL (which uses ; as separator). In the new CDK, the jdbc_url_params field is parsed by splitting on & and then passed as a Properties object to DriverManager.getConnection().

If you have configured jdbc_url_params using ; as the separator (which is the natural MSSQL JDBC URL format), the new connector would fail to parse them correctly — treating the entire string as a single key-value pair. This would produce exactly the error you are seeing.

Alternatively, this could be an issue with how the MSSQL JDBC driver (v12.10.1) handles the interaction between URL-level properties and Properties object properties in the new CDK.

To help narrow down the root cause, could you confirm:

1. Do you have anything configured in the JDBC URL Params field of your source configuration? If so, what separator are you using between parameters — & or ;?
2. Are you using CDC or standard cursor-based replication?

Please ensure you mask or remove any sensitive information (API keys, passwords, tokens, connection strings) before sharing any configuration details.

In the meantime, pinning to 4.2.6 is the correct workaround. I am escalating this to the internal engineering team for further investigation.

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[devin-ai-integration]

This issue has been escalated to the internal engineering team for investigation: airbytehq/oncall#11187

The team will investigate the JDBC connection string construction in the new CDK-based connector. In the meantime, please continue using version 4.2.6 as a workaround.

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[devin-ai-integration]

I have opened a Draft PR with a proposed fix: airbytehq/airbyte#72930

The issue is that the new Bulk CDK-based connector (4.3.x) only splits jdbc_url_params on &, but MSSQL JDBC URLs natively use ; as the parameter separator. The fix changes the split regex to accept both & and ; separators.

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