Bad Request: line 1:0 no viable alternative at input 'clear'

Question

I installed cassandra and run cqlsh:

Connected to Test Cluster at localhost:9160.
[cqlsh 4.1.1 | Cassandra 2.0.10 | CQL spec 3.1.1 | Thrift protocol 19.39.0]
Use HELP for help.

and enter clear command on cqlsh. But i got this

cqlsh> clear;
Bad Request: line 1:0 no viable alternative at input 'clear'
cqlsh> clear
   ... ;
Bad Request: line 1:0 no viable alternative at input 'clear'
cqlsh>

Answer 1

the clear command was added in Cassandra 2.2.1 (commit) and you're using very old 2.0.10. If you just learning Cassandra, start with Cassandra 4.x, not use the version that was released 8 years ago...