code: protected void initSchema(String signature) throws IOException
      {
          Properties properties = UDFContext.getUDFContext().getUDFProperties(AbstractCassandraStorage.class);
  
          // Only get the schema if we haven't already gotten it
          if (!properties.containsKey(signature))
          {
              try
              {
                  Cassandra.Client client = ConfigHelper.getClientFromInputAddressList(conf);
                  client.set_keyspace(keyspace);
  
                  if (username != null && password != null)
                  {
                      Map<String, String> credentials = new HashMap<String, String>(2);
                      credentials.put(IAuthenticator.USERNAME_KEY, username);
                      credentials.put(IAuthenticator.PASSWORD_KEY, password);
  
                      try
                      {
                          client.login(new AuthenticationRequest(credentials));
                      }
                      catch (AuthenticationException e)
                      {
                          logger.error("Authentication exception: invalid username and/or password");
                          throw new IOException(e);
                      }
                      catch (AuthorizationException e)
                      {
                          throw new AssertionError(e); // never actually throws AuthorizationException.
                      }
                  }
  
                  // compose the CfDef for the columfamily
                  CfInfo cfInfo = getCfInfo(client);
  
                  if (cfInfo.cfDef != null)
                  {
                      StringBuilder sb = new StringBuilder();
                      sb.append(cfInfo.compactCqlTable ? 1 : 0).append(cfInfo.cql3Table ? 1: 0).append(cfdefToString(cfInfo.cfDef));
                      properties.setProperty(signature, sb.toString());
                  }
                  else
                      throw new IOException(String.format("Column family '%s' not found in keyspace '%s'",
                                                               column_family,
                                                               keyspace));
              }
              catch (Exception e)
              {
                  throw new IOException(e);
              }
          }
      }
docs: Methods to get the column family schema from Cassandra