Tuncay Baskan (�nternet Grubu) wrote: > Hello all, > > Briefly, my question is not specific to Tomcat. I'm looking for answers > generally related with application servers, and tomcat user list is one > place really experienced and nice people exist. > > Here it goes... > > We are at the first steps of a big (well, for us it is big) project. On > our > part, there will be a database server (probably Oracle or DB/2) which > probably will have to be capable of handling more than 1,500,000 > transactions per day coming from POS machines all around the country. > Current infrastructure is based on mainframes and they are expensive to > maintain as you know.
> We won't be dealing with X25 to TCP/IP or other low level POS related > networking things. Those are considered as "outside world" for us. Here > is a > text diagram showing what we think for now: > > | > | +----------+ +----------+ > | | Server 1 | <----> | | > | +----------+ | | > | . | | > POS | +----------+ | Database | Report > machines | | Server 2 | <----> | Server | <-- stuff > (X.25) | +----------+ | | (internal) > | . | | > | . | | > | +----------+ | | > | | Server N | <----> | | > | +----------+ +----------+ > | > > Servers will operate the business logic; is message consistent, is it a > debit or credit, has owner enough credit, what type of smart card is > used, > etc etc. At this point I was thinking an application server can do it > well > enough (scaling for incoming connections, database connection pooling, > managibility, etc.) But, as far as i know incoming connections are not > HTTP. Application server is what you need to handle your kind of project. The purpose of the Application servers is centerlise your business logic at a single point. If you dont buy a off the self application server, you will end up developing your own. Application server do all the connection pooling, transaction handling, data persistence behing the scenes. This way the developer can concentrate on the application logic instead of dealing with the lower level nitty-gitty of connection pooling, security, transaction hadling etc. Certainly, the transport layer will not be HTTP unless your POS termincals are web browser. > > So, is it logical to use an application server to implement those > "business > logic units"? I think we need to implement, say POSServlet classes from > generic Servlet interface. Has anyone seen or developed something like > this > before? Or is it better to implement servers with ServerSockets? I don't > like the latter because imo, we need to "reinvent" a lot of things. > Sinc, you posted this question in a Tomcat list I assume, you are looking for the Java based Application Server. If my assumption is true, J2EE is what you need. There are commercial server like Weblogic and Websphare which will perfactly server your need. There are also opensource J2EE server. In my opinion, they do well in the small projects. You can load test them if they can serve your needs. J2EE servers comes as containers. For example Tomcat is web container for a J2EE server. Simmilary there are EJB container, JMS server, JNDI server etc. There is a possibility of mix and match the commercial and opensource containers. One of the actively developed opensource J2EE server is JBoss (I am using one for commercial applications). You will need a trasport to connect your POS terminals to the J2EE server. Natural choice for the any java aware application is to use the RMI or RMI over IIOP. HTTP is anohter choice if your POS are web browser. In that case you will need a web container e.g. Tomcat to up front the EJB Container. Offcouse you can get the integrated web containers and EJB containers from commercial vendor or you can integrate the tomcat with a opensource EJB server. If your POS clients are not Java application you will need some kind of bridge to connect to the J2EE server. If you intend not to use the J2EE server for any reason, you can have your own. Jakarta-avalon is another opensource movement which leverages is a component framework, server kernel, and a lot many ready made componets to assemble your own application server. I am working on such a project because, the open source J2EE server could not meet my requirements and commercial J2EE servers have a very high price tag which is not offordable by small entrprises. Regards, Raj Saini > I hope I explained the case well. I'm waiting for advices. > > Best regards. > > /tb. > > > > -- To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
