@Override
  public void perform() throws Exception {
    TableDescriptor tableDescriptor = admin.getDescriptor(tableName);
    ColumnFamilyDescriptor columnDescriptor = null;

    while (
      columnDescriptor == null
        || tableDescriptor.getColumnFamily(columnDescriptor.getName()) != null
    ) {
      columnDescriptor = ColumnFamilyDescriptorBuilder.of(RandomStringUtils.randomAlphabetic(5));
    }

    // Don't try the modify if we're stopping
    if (context.isStopping()) {
      return;
    }

    getLogger().debug("Performing action: Adding " + columnDescriptor + " to " + tableName);

    TableDescriptor modifiedTable =
      TableDescriptorBuilder.newBuilder(tableDescriptor).setColumnFamily(columnDescriptor).build();
    admin.modifyTable(modifiedTable);
  }
Action the adds a column family to a table.
hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/AddColumnAction.java