We are running SQL Server Connector 1.9.x in Production.

That connector cannot be upgraded to 2.0.
 

 Issue affects SQL Server Connector running in single-partition mode (this is important).
 

 The breaking change was introduced by DBZ-4726

• Before the change the single partition was identified just by server name

  public SqlServerPartition(String serverName, String databaseName, ...) {
      super(databaseName);
      this.serverName = serverName;
  
      this.sourcePartition = Collect.hashMapOf(SERVER_PARTITION_KEY, serverName); 

• Since 2.0 it is identified by server name and database name

  public SqlServerPartition(String serverName, String databaseName) {
      super(databaseName);
      this.serverName = serverName;
  
      this.sourcePartition = Collect.hashMapOf(SERVER_PARTITION_KEY, serverName, DATABASE_PARTITION_KEY, databaseName);
   

   

 
As a result the 2.0 connector does not see the offsets committed by 1.9 connector:

• In 1.9 offsets were created for

  ["my-connector",{"server":"db"}] 

• In 2.0 the offsets are created for

  ["my-connector",{"server":"db","database":"Db_Production"}] 

   

In consequence the upgraded connector starts as a new and unrelated connector, with initial snapshot et al - and not as a continuation of previous one.

 
The fix requires code change.

The potential workaround would require forging offsets in Kafka Connect topic (which should rather not be recommended)