public void run() {
			try {
				running = true;
		
				while (!stop) {
					Thread.sleep(60000);
					
					if (!stop) {
						try {
							env.checkpoint(null);
						}
						catch (DatabaseException ex) {
							throw new Error(ex);
						}
					}
				}
			}
			catch (InterruptedException ex) {
				if (stop) {
					try {
						env.checkpoint(null);
					}
					catch (DatabaseException dx) {
						throw new Error(dx);
					}
				}
			}
			catch (Throwable t) {
				System.err.println("HGDB CHECKPOINT THREAD exiting with: " + t.toString() +
						", stack trace follows...");
				t.printStackTrace(System.err);
			}
			finally {
				running = false;
			}
		}