<cell> – Required. A cell is a location for a service. Generally, a cell resides in only one cluster. In Vitess, the terms “cell” and “data center” are interchangeable. The argument value is a string that does not contain whitespace.
<keyspace/shard> – Required. The name of a sharded database that contains one or more tables as well as the shard associated with the command. The keyspace must be identified by a string that does not contain whitespace, while the shard is typically identified by a string in the format <range start>-<range end>.