Migration from Cassandra 2.x to 3.x: schema_keyspaces table is gone. How do you query system keyspaces?
There is a new system keyspace called "system_schema", but there are only two tables in it: 


Ok something must have gone wrong in your upgrade, because that's not right.  When I check my system_schema 3.4, I see this:

[cqlsh 5.0.1 | Cassandra 3.4 | CQL spec 3.4.0 | Native protocol v4]
Use HELP for help.
aploetz@cqlsh&gt; use system_schema ;
aploetz@cqlsh:system_schema&gt; desc tables;

tables     triggers    views    keyspaces  dropped_columns
functions  aggregates  indexes  types      columns  


There are definitely more than two tables in that keyspace.


  How do I query to see what keyspaces are available?


The new way to do this, is to query system_schema.keyspaces:

aploetz@cqlsh:system_schema&gt; SELECT * FROM keyspaces;

 keyspace_name          | durable_writes | replication
------------------------+----------------+-------------------------------------------------------------------------------------
        zeroreplication |           True |       {'DC1': '0', 'class': 'org.apache.cassandra.locator.NetworkTopologyStrategy'}
            system_auth |           True | {'class': 'class': 'org.apache.cassandra.locator.NetworkTopologyStrategy'}
          system_schema |           True |                             {'class': 'org.apache.cassandra.locator.LocalStrategy'}
          experfy_class |           True |       {'DC1': '1', 'class': 'org.apache.cassandra.locator.NetworkTopologyStrategy'}
                 system |           True |                             {'class': 'org.apache.cassandra.locator.LocalStrategy'}
          stackoverflow |           True |       {'DC1': '1', 'class': 'org.apache.cassandra.locator.NetworkTopologyStrategy'}
              eqcontrol |           True |       {'DC1': '1', 'class': 'org.apache.cassandra.locator.NetworkTopologyStrategy'}


The main difference between system.schema_keyspaces and system_schema.keyspaces, is that system_schema.keyspaces only has 3 columns instead of two (strategy_class and strategy_options were combined into replication).