Support to delete multiple keys in one DEL command.
The feature of returning number of the really deleted keys is still not supported.
Return empty string to client for GET command when the required key is not exists.
Fixes: #5334
Signed-off-by: Peng Jian <pengjian.uestc@gmail.com>
Scylla has advantage and amazing features. If Redis build on the top of Scylla,
it has the above features automatically. It's achived great progress
in cluster master managment, data persistence, failover and replication.
The benefits to the users are easy to use and develop in their production
environment, and taking avantages of Scylla.
Using the Ragel to parse the Redis request, server abtains the command name
and the parameters from the request, invokes the Scylla's internal API to
read and write the data, then replies to client.
Signed-off-by: Peng Jian, <pengjian.uestc@gmail.com>
