BATCH: Extend driver API: add USING TIMEOUT for BATCH queries

[moguchev]

According to the ScyllaDB CQL specification, for BATCH queries, you can define a server timeout using the USING TIMEOUT construct:

In Cqlsh we can do this:

BEGIN BATCH USING TIMEOUT 500ms
   INSERT INTO users (userid, password, name) VALUES ('user2', 'ch@ngem3b', 'second user');
   UPDATE users SET password = 'ps22dhds' WHERE userid = 'user3';
   INSERT INTO users (userid, password) VALUES ('user4', 'ch@ngem3c');
   DELETE name FROM users WHERE userid = 'user1';
APPLY BATCH;

But in gocql and gocqlx we can't add any update parameter:

: [ USING `update_parameter` ( AND `update_parameter` )* ]

[dkropachev]

CQL4 frame for batch and regular queries does not have place for timeout, therefore we can't do that through regular batch API, and we don't have API to compose textual BATCH query.

So, probably we should ask core to add timeout to the protocol.

[Lorak-mmk]

So, probably we should ask core to add timeout to the protocol.

Or even better add support for CQLv5, instead of backporting 90% of it to CQLv4 through billion protocol extensions.

[mykaul]

So, probably we should ask core to add timeout to the protocol.

Or even better add support for CQLv5, instead of backporting 90% of it to CQLv4 through billion protocol extensions.

Where is it in CQLv5? I only see:

Allows executing a list of queries (prepared or not) as a batch (note that
  only DML statements are accepted in a batch). The body of the message must
  be:
    <type><n><query_1>...<query_n><consistency><flags>[<serial_consistency>][<timestamp>][<keyspace>][<now_in_seconds>]

[Lorak-mmk]

Ah sorry, I forgot that USING TIMEOUT is a Scylla-specific syntax.