IN MEMORY OBJECT SERVER BASED APPLICATION FOR RAILWAY COMPANIES

Miloš BudinskýSiemens PSE

ROMAN Modules• ROMAN Ordering (Order Managment)• ROMAN Calculation (Runtime Calculation)• ROMAN Planning (Timetable Planning)• ROMAN Cross Border• ROMAN (Cross Border & Cooperative Planning)• ROMAN Resource (Crew scheduling and dispatching)• ROMAN Anywhere (Timetable Viewer)• ROMAN Products (Timetable Planning Products)• ROMAN Periodic (Synchronized Timetable)• ROMAN Public (Public Timetable)• ROMAN Simulation (Timetable Simulation)• ROMAN Solver (Dispatching & Conflict Resolution)• ROMAN Connect (Interfaces)

Application domain

• Users: Railway companies

• short term train planning

• train dispatching

• conflict detection

• resolving train conflicts

• searching for free train paths

• long term train planning

Overview

• a Java based technique

• a real time in memory system

• intranet/internet

• client/server application

In memory object server

• in memory object server

• object graph pre-linked during the server startup

• high performance

• operation memory resident object server

Topology graph based container

• a Railway-Topology-Graph • container keeping other business objects (like

trains, runtime tables, design areas, etc.). • most business objects in this application domain

are either graphs and its sub-graphs (a country track topology, design areas…)

• oriented paths in the graph (trains, runtime tables…).

Object model examples of graph, sub-graph, path

Tracksection

TrainRunning

DALocation

DASection

Group

DesignArea

“Topology Graph based”

container

Location

Train

Performance

• Fast traversing this pre-linked graph object leads to a high velocity of queries

• an easy straightforward implementation of even very complicate business rules.

Design Areas

DA-sections

Groups

DA-locations

Trains

TrainRunnings

TrackSections

Example: collecting Train Graph objects

Example: collecting Train Graph objects

Design Areas

DA-sections

Groups

DA-locations

Trains

TrainRunnings

TrackSections

Persistence

• The persistence layer uses an object oriented XML file system storage

• (alternatively this system can be connected with a relational database(s)).

Other features

• thin client

• Java Webstart desktop application

• Servlet (Web Container) – for WWW

• Java-RMI – for LAN

What could be target market?Several (very different) directions:

Solveror

Many types of Viewers (like OBB)or

Crossborder like solutions (on the internet?)or

Cheap train design package for small companies (public traffic, metro…)

Architecture

Thin Client

Application / Webstart

Applet / Web-browser

Web Container

Servlet JSP

EJB Container

EJBDB

Server

In memory Object Server

XML Persistence

Let’s start from well known picture - J2EE with EJB

Thin Client

Application / Webstart

Applet / Web-browser

Web Container (Tomcat)

Servlet

In memory Object Server

XML Persistence

Current status

DB

Thin Client

Application / Webstart

Applet / Web-browser

Web Container (Tomcat)

Servlet

In memory Object Server

XML Persistence

Scalability

Object Cache

Web Container (Tomcat)

Servlet

Object Cache

Persistent objects representing minimal units for serialization in the current version:

• Location• Line• Train• View (DA)• Multi-View• Block• Multi-Block

• Train-Class• Location-Class• User

Similar In-memory-objects

Approaches• Prevayler (Object prevalence)

• JISP

- They uses memory resident object-graph server

Data Model

Connection

Connection

Connection

Line

Topology – high level

Loc

Loc

Loc

Loc

Loc

Loc

Tracks

Topology – Location details

Loc

Topology – Location details

Location:

Node= switch

Edge= locTrack