Hospital information system in our country after 20 years of development, now more than 40% of the hospitals are building floor a few words of the management information system, application system diversity, wide range, the module number, access frequently, mostly adopts client/server mode, maintenance complex, and the popular for many years and mature distributed

The application of the technology, the application server and Web technology is rarely, such as running in my hospital information system, application module (subsystem) has more than one hundred, HIS master database server connection count peak has exceeded 1000, thus, large general hospital on the system application will also encounter: database

The number of connections, frequent data access and system pressure; System coupling between high, extend the difficulties of all kinds of problems, from now, and if the system of C/S two layer architecture to distributed multi-tier architecture to migrate to upgrade, can solve the problem of system faces a series of,

1
the current system facing problem
1.1 system performance bottleneck is outstanding in our development of HIS system, adopts the traditional C/S architecture, the client application system directly connect to the database system, a client needs to take up at least one database connection, some large amount of data query is limited in certain period to use, this situation not only caused great information

Source of waste, and under the big concurrent database under the heavy pressure and cannot handle business requests, quick response and result in low system performance of the system, in practice, should be used every day rush hour system connected to the main server user session number more than 1000, especially in large scale and huge traffic system on Monday

More low performance of the system, not only for business units are not satisfied, also let the computer center personnel more nervous and busy,

1.2 business rules in urgent need of reforming the system development business rules in the reuse USES the following two ways: one is the database of store process, or function, the second is on the client side through PBL Shared or Shared objects, but these two methods are not too ideal, the former not only difficult to write is larger, and will increase the pressure of the database, the latter

Usually is not very good control version of consistency, and caused the larger distribution and maintenance workload, to solve these problems need to be adopted between the server and application of multilayer distributed architecture of ideas, in order to reduce the difficulty of the development and maintenance and workload,

1.3 system coupling, high integration difficult at present, the large and medium-sized hospital of hospital informatization construction has shift from management services to the surface to clinical service oriented, comprehensive digital hospital construction, system application is wide, deep, module, forced cut system integration, need to be solved due to the body of the hospital information system is

System, developed with other systems (including lead) into the system integration directly adopts point-to-point integration structure, when the system coupling between sex is very strong, at the same time, along with the development of the system, not only need to process management, marketing channels, and integrate the aspects such as external services [1], and it may need from the data, application interface, the interface, three layer

Surface to achieve integration, led directly to the difficulty of the integration and complexity, the need to seek suitable for more advanced way of integration, such as hospital information system based on SOA and flexible process integration, to construct/upgrade the whole hospital
[5] information system,

1.4 C/S architecture system application development of traditional C/S two layer structure of application system, suitable for small and medium size between the amount of data the business system, mature technology, stable, is still a large number of use, however, two layer system architecture in the big concurrent, Internet deployment, system deployment and maintenance of limitations inevitably restricted

System of horizontal, vertical deeper development,

At present, our hospital HIS system main body is to use PB + Oracle development of traditional C/S architecture, with the development of tongji hospital information system applications will be increasingly large scale, according to the present access method is expected to peak time the number of connections in the future are likely to break through 2000, the system application requirements will enter the cross-regional interconnection and interflow,

And need to provide Internet information release and the service of diverse applications such as stage, therefore, the system architecture has restricted the further development system, it is necessary to upgrade the system architecture of migration,

PB 2 C/S system migration scheme comparison analysis

Multi-layer architecture is proposed to solve the two layers architecture faces all sorts of problems, often referred to in "layers" mainly for the points system and B/S (Browse/Server) system, in tongji hospital information system of the three layer architecture of upgrading the migration refers to the multi-layer distributed system architecture, at the same time, based on the hospital HIS system

System development tools and the concrete application situation, has the following several migration scheme can choose,

2.1 use J2EE/.NET to develop B/S structure to abandon PB, using Java/.NET to rewrite the system module, rewrite the WebForm into B/S architecture, although this migration scheme can be in accordance with the latest architectural design, can be realized by using the latest technology; B/S architecture WebForm allows client minimizing maintenance work such as

Advantages, but there are also several key problems: the migration cycle is long, high cost, scale, at present the hospital system, to adopt J2EE or. NET development, improvement, not only time-consuming, but also because of adopting new technology architecture, the old technology investment and personnel structure also can not get effective protection and continuity; Low response speed

, poor user experience, acceptance is low, although B/S system that can reduce a lot of implementation and maintenance workload, but is not suitable for OLTP business system, so far, the B/S system of Web Form interface is difficult to achieve the traditional Windows Form of friendly interface and simplicity, and response speed relative to the

Low,

2.2 use Appeon migration into B/S architecture Appeon is used to transfer the PB system, although a high degree of automation, big part of the advantages of simple procedures can be automatically convert, but Appeon migration system, several key problems: the same product distribution cost is high, Appeon migration cost is not high, but by the

After the migration of products in accordance with the resistance to Appeon run the environment seriously, which greatly increased the issuance of product cost and the difficulty, therefore, Appeon type suitable for migration project system (project), and commercial product is not suitable for migration; There are security hidden danger, Appeon USES is OCX way to adjust local resources

Use and interface display, on the one hand, in many cases, OCX often thwarted by the browser, on the other hand, there are also may be used and attack; Appeon is simply the C/S program "translated into" B/S, has not wanted for modular encapsulation and the business logic and other work, want to undertake the work, you need to be summarized rules

Stroke and development,

2.3 with PBnTierBuilder migration into a multi-tier architecture [2] the PB PBnTierBuilder migration system, advantage is obvious: with PB perfect partner, sustainable development, make full use of the existing technical personnel resources, achieve smooth technology upgrading, can guarantee the smooth migration of the system; Migration upgrade is simple, only need to

Simple "translation" of the original system (the Datawindow, embedded SQ rewriting), a code migration can be realized to rewrite, meet a variety of technical architecture (distribution type multilayer IIOP and HTTP, the.net SmartClientWinForm, ASP.NET WebForm, etc.), and can support

A variety of database systems; Parametric component design idea based on SOA, facilitate system integration and maintenance management; Using efficient data compression (up to 20 times the compression ratio), and other technology, the Internet environment is running speed, using PbnTierBuilder migrated system, running on the Internet has very good performance, and system

Distribution of low cost, this solution compared to Appeon slightly lower degree of automation,

From above, the technical features of several schemes, and combined with the specific situation of the hospital system, we believe that with PBnTierBuilder moved move update PB C/S system is most appropriate,


3 PBnTierBuilder migration scheme
3.1 based on the Sybase EAServer key technology of multi-tier architecture [3-4] Sybase EAServer is used to provide high reliability, high performance and manageability of enterprise distributed, client/server, Web application solutions, make existing application set into the J2EE environment and service oriented architecture (SOA),

The Jaguar CTS (component transaction server), Sybase is a new adaptive component architecture of the middle layer of the core products, it is the application types of multilayer structure oriented enterprise client/server applications and Web OLTP applications,

Sybase EAServer multi-tier architecture has the following several key techniques: the distributed and component technology, the business process layer and interface layer on the separation of the business process layer are abstracted into components, deployed on the application server, such not only can achieve the goal of database, the business process layer, interface layer to deploy on multiple computers, and

And the realization of distributed processing, make full use of the powerful features of the application server, realize the resource sharing, load balance; Database Connection buffer pool, the application server provides a database Connection buffer pool (the Connection Cache) technology to realize the database Connection sharing, namely in the component database Connection for logic series Connection, group

A dynamic in time of need to get a database connection from the pool, after use and release to the pool, greatly lower the actual number of database connections, alleviate the pressure of the database, and improve the system performance; Component instance buffer pool, the client application to connect to the server, application server USES the component instance buffer pool technology

(Instance Pooling) implemented only if there is a need to perform specific method to a component Instance from Instance buffer pool for binding, execution of the method and then released into the buffer pool; Application server cluster, through the application server cluster to solve the concurrency and improve performance, and the database cluster (such as Oracle's

RAC cluster) in comparison with better scalability and comprehensive cost,

3.2 PBnTierBuilder function composition [2] PBnTierBuilder is based on the Sybase EAserver structure, serve the Sybase bridge between technology and application developers, set of server components, client extension (interface) components, secondary development tool in the integration of development tools, mainly has the following several parts: the

Server-side components, including the standard data service component, a common function components and user expands itself components, can be deployed to Sybase EAServer (5. X/6. X) or IIS (5/6/7) +. NET Framework2.0 above; Client extension (interface), including collection of client interface, for different deployment architecture provides different

The adapter set; Configuration tool, auxiliary tools, including the system data server configuration tool and secondary development tools, to realize the management of the system parameters and the maintenance of server data object, figure 1 is PBnTierBuilder technology architecture,


3.3 PBnTierBuilder migration steps

3.3.1 transfer building nTier applications (development) environment which includes the need to install a EAServer5.0 above version of the application server, and in accordance with the requirements for PbnTierBuilder component deployment, the Connection Cache Settings such as configuration,

3.3.2 rainfall distribution on 10-12 PbnTierBuilder contained in the client program application Target client extension PBL is based on the old C/S listed on creation of a new Target, in addition to the original need to include all of the PBL, but also contains PbnTierBuilder client terminal extension of PBL (PBD) revealed considerable variation, so that you can direct call

PbnTierBuilder provides easy to use, powerful data operation function,

3.3.3 construct basic nTier nTier application running environment is not like the traditional C/S application direct access to the database, but indirectly through the application server to access the database, so it is necessary to increase the migration of the client program connect to Jaguar server, create a sequence such as the remote object proxy nTier run rings

In code,

nullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnull