Kafka HBase Sink Connector unable to deliver its messages to HBase - ssl

Question

I have particular Kafka HBase Sink Connector problem for which I will appreciate any advise or suggestions.
It is a 3-node Kafka cluster - 2 nodes for connect-distributed and 1 node for schema registry + kafka streaming. The Kafka version is 0.10.1 and is part of the Hortonworks platform 2.6.3. There are SSL and Kerberos authentication settings also. On top of it I have custom Kafka application that receives messages, processes them via Kafka streaming and delivers them in HBase.
The process model is:
1) Input topic;
2) Processing (in Kafka streaming);
3) Output topic;
4) HBase sink connector;
5) HBase.
The delivered messages in 1) are successfully transferred and processed until the step 3) inclusive. Then the though the sink connector works fine no message is delivered to HBase.
That being said I tested our custom application model with the Unit tests creating embedded Kafka cluster with its own basic settings and the tests were successful. This could quite likely indicate that the connectivity problem comes from some cluster setting(s).
For your information I observed 3 specific things:
The standard consumer console functionality is able to successfully consume the messages from the sink topic;
There is no consumer id for the sink connection established;
The process of connections starts successfully but stops for not logged reasons and do not call the WorkerSinkTask java class, where actually the writing to the HBase happens.
Addtional important point is the whole SSL encryption and Kerberos authentication setup that might be misconfigured.
In case anyone faced such a case I will greatly appreciate any comments that could be of a help.
Dimitar