public void takeColumnFamilySnapshot(String keyspaceName,String columnFamilyName,String tag) throws IOException {
  if (keyspaceName == null)   throw new IOException("You must supply a keyspace name");
  if (operationMode == Mode.JOINING)   throw new IOException("Cannot snapshot until bootstrap completes");
  if (columnFamilyName == null)   throw new IOException("You must supply a table name");
  if (columnFamilyName.contains("."))   throw new IllegalArgumentException("Cannot take a snapshot of a secondary index by itself. Run snapshot on the table that owns the index.");
  if (tag == null || tag.equals(""))   throw new IOException("You must supply a snapshot name.");
  Keyspace keyspace=getValidKeyspace(keyspaceName);
  ColumnFamilyStore columnFamilyStore=keyspace.getColumnFamilyStore(columnFamilyName);
  if (columnFamilyStore.snapshotExists(tag))   throw new IOException("Snapshot " + tag + " already exists.");
  columnFamilyStore.snapshot(tag);
}

public void takeColumnFamilySnapshot ( String keyspaceName , String columnFamilyName , String tag ) throws IOException { if ( keyspaceName == null ) throw new IOException ( "You must supply a keyspace name" ) ; if ( operationMode == Mode . JOINING ) throw new IOException ( "Cannot snapshot until bootstrap completes" ) ; if ( columnFamilyName == null ) throw new IOException ( "You must supply a table name" ) ; if ( columnFamilyName . contains ( "." ) ) throw new IllegalArgumentException ( "Cannot take a snapshot of a secondary index by itself. Run snapshot on the table that owns the index." ) ; if ( tag == null || tag . equals ( "" ) ) throw new IOException ( "You must supply a snapshot name." ) ; Keyspace keyspace = getValidKeyspace ( keyspaceName ) ; ColumnFamilyStore columnFamilyStore = keyspace . getColumnFamilyStore ( columnFamilyName ) ; if ( columnFamilyStore . snapshotExists ( tag ) ) throw new IOException ( "Snapshot " + tag + " already exists." ) ; columnFamilyStore . snapshot ( tag ) ; }
takes the snapshot of a specific column family . a snapshot name must be specified .
