Question about client/server design

I designed a server for a particular service. On the client side, how could it know that the server is up and running? i.e. how to make the client know that the server with the particular service is available?
Thanks.

When client started, if use udp to check the serveres
is running or not, I think it is difficult. For so
many port and so many serveres, how can you check?A single defined port is used for the service query. Regardless of what you do something must be defined ahead of time.
DHCP works this way. When the client starts up it does not even have an IP address. There is a defined DHCP port for this (which is actually configurable on server and client but is seldom changed from the default.)
>
So my suggestion is that when server started, it
register itselfto a central server. Then central
server will send some common request to those
registered server. If some registered server cannot
work, they will be removed from central server.Yes you can use a service manager process. Even with that process it will still require a defined port though.
Services could be registered using push, pull or both. Normal the following interactions would occur for this system.
- On start up the client service must locate the manager server. It can either use a broadcast or configured location.
- Once the server is located the client service registers itself and the services it provides with the manager.
- Finally some polling logic is needed to very that each end is still alive. One end (A) sends a poll message and the other(B) responds. If there is no response then A takes some action. And if B does not recieve a poll message after a given period it takes some action.

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Questions about application server architecture

Hello guys,
I have few questions about application server architecture�
I have a task to build a server application which will do the following: Clients (special java clients) will connect to it and send some data for further processing on server side. Chunks of data will be relatively small but they will take a lot of time for processing (it is ok that it will be quite slow).
Also server will run some sort of �database� where all clients� working data will be stored. So, in case a client loses its data he/she is always able to download it from the server.
For me it seems, like server will consist of the following components:
1. �Reception�. This part will be responsible for all client-communication procedures.
2. �Data storage�. This part will simply store all clients� data and provide some API interface for clients through �reception� to manage it (add/get/delete and so on).
3. �Processor�. Some sort of dummy-sophisticated module. It will take some input data from �data storage� when it receives order for this and process it. �Processor� will have two states: �busy� which means �processor� processing some data and �available� which means �processor� ready to process new data.
4. �Manager�. This part will always check �data storage� for new data and �processor� for availability. When �processor� and new data are available �manager� will make an order for �processor� to take new data from �data storage� and process it.
So, my question is the following: Which technology and approaches I should use to realize my plan?
I think that I can make �reception� as a Session Bean, but I don�t know yet, what are the best for the rest, for example �manager� and �processor�. I was thinking about writing my own application server (and I can do it), but I would like to learn j2ee technologies, so I think it is a perfect chance for me (I read a lot about j2ee before I wrote this post, but all examples have only �account�-�bill�-�money transfer� I think it is quite far away from reality or I am doing something wrong ;-)!
p.s. I am thinking about using JBoss as an Application Server. I tested it and wrote some tests. They work and run fast enough, so I like it. Moreover it has module architecture.
Please, give me some advises and tips!
Thank you in advance!

1. �Reception�. This part will be responsible for all
client-communication procedures.Session bean with remote interface.
2. �Data storage�. This part will simply store all
clients� data and provide some API interface for
clients through �reception� to manage it
(add/get/delete and so on).Session bean that will use entity beans or hibernate to work with persistant data.
3. �Processor�. Some sort of dummy-sophisticated
module.Use a message driven bean. Make Reception to enqueue a message when new data is available for processing. Processor will process the data and store the resut in database using Data Storage session bean.
4. �Manager�. This part will always check �data
storage� for new data and �processor� for
availability. When �processor� and new data are
available �manager� will make an order for
�processor� to take new data from �data storage� and
process it.It's redundand component, because application server will manage messages and processors.

A question about VI server

Dear all,
I have some confusion about VI server. Suppose I
have two computers, computer A will be used as a client
and computer B will be used as server. A wants to get
access to a VI (test.vi) on computer B. What
requirements should computer B meet?
1). Run LabVIEW?
2). Run test.vi?
3). Run test.vi by open VI reference?
Does computer B should meet all the requirements?
Thanks a lot for your help!
Regards,
Tao Song
Mechanical Engineering Dept.
Univ. of Maryland, Baltimore County

Dear Mike,
Thanks a lot for your help! I think I understand it
now. Unlike the datasocket which has a separate server
program, for VI server LabVIEW itself works as a
server so it has to be runnig to listen to a port. Am I right?
But I still have doubt that if test.vi has to be loaded
into memory on computer B. If I use property and
method node on computer A, such as FP Open and Run VI,
can I remotely control computer B to load test.vi into memeory
and run it?
Thanks a lot! I really appreciate your help!
Best regards,
Tao
"mikeporter" wrote in message
news:[email protected]..
> Computer B has to be running LV or LV runtime and test.vi has to be
> loaded into memory and be ex
ecutable (i.e. not broken).
>
> From Computer A you first open a reference to the copy of LV running
> on Computer B. This means you have to know the name or IP address of
> Computer B, and the port number that LV is listening to for
> connections (which is configurable through the Options dialog box, or
> by editing Computer B's *.ini file directly).
>
> Once you have the reference to the copy of LV, you open a reference to
> the remote VI (test.vi) by name with a type specifier defining the
> structure of test.vi's connector pane.
>
> Connect this VI reference to a Call by Reference Node and you can run
> the remote VI.
>
> Be sure to close all the references when you are done with them as
> this can cause a major memory leak...
>
> Mike...

Question about service layer design

I have a question about the design/architecture of service model layers, specifically the task service layer.
Could a task service be a small "action", ie an operation that doesn't require composition? So if I have a requirement to allow customers to update their personal info, like address, would I have a task service named ChangeCustomerMailingAddress, that in turn calls the update operation on the Customer entity? Or would it be better to call the entity service directly? Another example would be retrieving data, like RetrieveCustomerBillingHistory, would that be a separate task service, or just a get/read operation on the Customer entity service?
Any insight is appreciated.
Thanks

You seem to be confused what all the different parts of Java do.
JRE - runtime environment, the minimum needed to run standard java applications
Java Standard Edition - the standard set of API's that form the base of most java applications. You need the J2SE SDK to compile these applications and the JRE to run them.
Now talking about "application design", I'm not sure what you mean. Are you talking about graphical user interfaces? In that case you would want to look into Swing, and that is indeed part of the standard edition API set.

An rmi client server design problem

I am implementng a networked cards game in java using rmi . The server keeps track of the turn of the players and activates ther clients(on an applet) whose turn it is to play .
Both client and server call each others methods.
Prblem one :
Right now if a a client disconnects , a process run through all the clients active and gets a remote exception on the server and removes ALL the 4 players i nthat particulat group. If I want to save the state and allow any player to contuniue from there , how will I do it?
Problem 2:
How do I keep track of the time a client takes to play.
If he takes longer than say 5 mintes , I should disconnect him.

There seem to be two issues at stake: catching the remote exception and multithreading your application on the server.
When a client disconnects "suddenly" (without logging off via remote method call to alert server), the remote method call by the server to all n players triggers a remote exception that must be caught and dealt with accordingly (do I understand that it is causing the application to exit at present?) When caught, you must identify which player is "gone" and remove that client from the pool of client objects.
Right now, it sounds as if the app is NOT multithreaded. You can create a low-priority thread that looks at a time variable for each player to determine its last moment of play. This means every successful remote call from client-server or vice-versa will update that client's 'lastplayed' variable with (long) System.currentTimeMillis() for example.

Some question about the query designer

hello, dear all,
I am a new comer of here, and I am intersting in BI, but I have no basic knowledge about it.
so I just want someone could give me some advice about it.
our boss need I do the developer about the query designer, I just have searched in this forum. but nothing founded for I am a new comer here,
I heard there are some training document of the query designer, could someone give me the URL, thanks.

Hi,
Query desinger is used to develop a Query, Query can be created on following data targets
-Info Cube
-DSO
Virtual data target
-MultiCube
-Infoset
-Multiprovider
We have 5 section in query designer
- Infoprovider : where we select the data target , on which report to be created
-Filter : to restrict value at infoprovider level ( if you want data for year 2008, for example)
-Free Characterstic : this allow you to drill down
-Columns : char/keyfigs to be display in columns can be added here
Row: key/char to be display in Rows can be added here
gv me ur mailid i will let u have Bex manual,
I would suggest , if you have any IDES ( training ) system , where you can log in and then go to RRMX,
and try to create new query and add any data target ( which is already created ) and then drag and drop the char/key fig to the required section ,
save it and execute it .....
if you play arround and see the output , that would help u to understand how to work with query designer.
Hope this helps
Sukhi
Edited by: Sukhvidner Singh on Nov 4, 2009 5:36 PM

QUESTION ABOUT CLIENT ACCESS ROLE AND MAILBOX SERVER INSTALLATION ON DIFFERENT HOSTS

If i install one mailbox server and three client access servers on three different hosts,then what will be the url to open ecp and owa?and also to do this kind of installation,what should i do?please help.
trainee

Well, you can open ECP URL Internally by using any of following URL
1. https://host1/ecp
2. https://host2/ecp
3. https://host3/ecp
OR if you have DNS entry for mail, lets say mail.domain.com then you can open your ECP using https://mail.domain.com/ecp
As far as deployment is concerned i won't recommend this deployment. You are trying to achieve HA of CAS server role but mailbox server role who will be performing most of the Exchange 2013 tasks is not redundant. I would recommend you to have 2 CAS servers
in NLB with 2 Mailbox Servers in DAG for HA. Exchange 2013 is loosely coupled and you can install any of these roles first. Thanks.
Hope this answers your questions. Kindly mark this as answer if found helpful.
Regards, Riaz Javed Butt Consultant Microsoft Professional Services MCITP, MCITP (Exchange), MCSE: Messaging, MCITP Office 365

Questions about RH Server features

Hi Adobe users,
we're considering to recommend RoboHelp Server as a
publishing solution to a client. They are already using RoboHelp
and want to make the contents available online. Another issue is
centralized management of their help content documents. I'd be very
glad if someone could answer the following questions:
Is it possible to integrate RH Server
with a CRM system or another user management system for
authentication? Can it be integrated in a single sign-on
infrastructure?
How does the access control mechanism
work? Can I set permissions who is allowed to publish certain
documents/projects?
Does it support workflows
(review/accept/reject)? Or is this done using the staging
server?
Does it support content versioning?
Or do we need RH SourceControl for that additionally?
Does it support locking (check-in,
check-out) of documents to allow concurrent editing?
In short - does the RoboHelp server act as a document
management system, or do the authors have to store the contents on
their local computers and publish only the final version? Another
issue is translation management - can the authors publish one
language version, which is translated by other people (in other
countries) and published to the same server?
Thanks a lot in advance for any help!
Andreas Hartmann

Wow, Andreas. Welcome to the Forums.
That's quite a laundry list!
The answers are pretty much, "yes", if I understand
correctly. That said, I don't know that much about CRMs, so your
mileage may vary.
To start, you might want to take a look at my article on the
Adobe Developer Network for an overall perspective.
Adobe
RoboHelp Server 6 improves the feedback loop
I view RoboHelp and RoboHelp Server as a "content" management
rather than a "document" management system though this is a bit a
semantics. Using variables, conditional build tags and Single
Source Layouts, you can manage the content of your output in a
fairly granular way (including to some level, your translation
issues).
In other words a team of multiple authors can manage the
content of a website in the way you describe with a combination of:
1. The authoring client (RoboHelp's main application) to
develop content and manage it.
2. RoboSource Control (for the check in, check out and
versioning you mentioned) where authoring content source material
is stored on a central server for backup and access by the team.
3. RoboHelp Server for managing the authentication of who has
access to the web server for publishing, etc. RoboHelp Server is an
Active Server Pages application running on IIS, typically with a MS
SQL Server or Oracle DB as the back end. As such, it uses Windows
Server straightforward authentication methods. When you set up the
author's project to publish to the server it will ask you for the
Username and Password. Once this is configured, it's seamless from
there. That login name/password can be the same as whatever you
call your single sign-on pair as long as it conforms to the Windows
Server scheme mentioned earlier.
The RoboHelp author who may be designated as the "admin(s)"
of the team can create and assign permissions from the authoring
client and otherwise manage the Server site remotely without having
to pester the Web Administrator for maintenance of the site.
The staging server scenario you mention is an option that is
completely up to your team and the IT folks. RoboHelp Server
doesn't care one way or another. It's just an application sitting
on a IIS web server. That server could be the "development or
staging" server or the so-called "production" or live server.
The different languages you mention could be published to the
same server and comingled into a single site (kind of messy) or you
could have different language sites (as long as they are different
domains/IP addresses) sitting on the same RoboHelp Server enabled
machine.
Regarding language, one important item to research is the
RoboHelp version you are using and it's language support. The
much-anticipated Adobe RoboHelp 7 (now in beta and expected "before
the end of the year") will have full Unicode/double byte character
support for 35 languages and a wonderful way of handling
translation workflows.
Well, that should get you started. Let me know what I've
missed!
Thanx,
john

I have a question about flash website design and google indexing!

first off i want to say I hate HTML (call it HTM HELL) I love Flash.Im a big propononent of flash.OK about a month ago I built a 100% flash site,told google to crawl it,then come to find out they cant see any text inside images.So I did what i didnt want to do,I took all my hard work down and had to work even harder and created a fully 100% HTM hell site.and just under 4 weeks later google still has my flash site in its cache.the question im trying to get at is if google cant read 100% flash sites whats the point in creating flash sites(mine's a business site.)I want to get into creating flash sites for other people too but if google cant read them how would a person be able to do a search for say what i do:pc repair in google & then my flash site would come up in googles search results.This is potentially costing me lots of money.I dont like "coding" HTML i want to design in flash.HEEEeeelllppp!

Google can crawl Flash, though I'm not sure how well, but either way nothing can read text that is not text - ie an image. The workaround - and still relevant for all other search engines, is to put all your content inside the div tag that your Flash is written into. The alternate content that one would see if they didn't have Flash, or didn't have JavaScript enabled.
There is a good tutorial on SEO with Flash on the SWFObject site: http://blog.deconcept.com/2006/03/13/modern-approach-flash-seo/
You can also just Google 'Flash SEO' and get a good deal of info.

Question about Lion Server usage...

Hi there!
I'm new to Lion Server (at most, I had used the SL sharing preferences, but never the Server Admin or any of those tools...)
I'm having some troubles understanding Lion Server. First of all... where are all the files stored?? I know the web server files are stored at /Library/Server/Web... but what about all mails, wikis, and those files?
That is one question... the other one is... while fiddling with the wiki server I noticed that when I created a user, it's profile page is saved on the wiki and when I delete that user, the wiki document is still there! Wasn't it supposed to be deleted as I deleted the user itself?
I can't seem to find a manual or something, only for SL Server not Lion.
Can someone please help me out?
Thanks!
- Eduardo

Eduardo
At the moment there is very little for Lion Server. What little there is, is here:
http://www.apple.com/uk/support/lionserver/
and here:
http://manuals.info.apple.com/en_US/lion_server_upgrading_migrating.pdf
The administration manuals take some time to become available which is usually the case when Apple release a new version of the Server Version. However most of what's there does not change that much and generally the 10.6 Administration Manuals will contain most of what will eventually become the 10.7 Administration Manuals. Again this has always been the case going back to at least 10.3 Server. Technologies introduced in 10.5 Server such as CalDAV, Wiki and Blog etc did not change that much in 10.6. Apple also moved away from Cyrus as one of the Mail MDAs to Dovecot. But again the locations of where these were stored did not change. Going back to CalDAV and CardDAV these now appear to be amalgamated into one store.
As ever with any version of the Server - regardless of platform or age - it's a good idea to have plenty of backups and to experiment first with a test/lab environment before rolling it out to a full production server.
HTH?
Tony

Question about Client Push Installation configuration

Hello,
I am trying to configure client push installation. Can you please tell me what is needed for the field "Network Share"? I see sample examples listing <server name>\admin$ or server\share. My admin share on my server
is c:\windows. Is there a directory that is needed here such as the client software? If so, I see a directory under C:\program files\Microsoft configuration manager\client. Please advise on the next step. Thanks for any help.

Are you talking about this?
This is optional. You don't need to use this at all. It's just to verify that the account details you have entered are valid (ie test connection).
Note that your client push installation account has to be local administrator on all devices on which you want to install a client.
Gerry Hampson | Blog:
www.gerryhampsoncm.blogspot.ie | LinkedIn:
Gerry Hampson | Twitter:
@gerryhampson

Question about Object-Orientated design for GUI'S

Hi everyone,
I am designing a simple GUI, which basically enables a user to input and retreive data.
So I have a prototype GUI lets call it "myFrame". It extends JFrame, and I place my components onto myFrame, JButtons, JTextfields etc. I have the GUI set up the way I want it, so I move onto implementing the actionListeners.
The problem is that one of the components I have placed on myFrame has its own mouseListener. Its a type of Icon (i created in a seperate class)which extends JComponent, and I thought it would be sensible to give it control of its own mouseListener, so it cuts down on the code within the myFrame class.
But I now realise that I can't alter the other components on myFrame from within the mouseListener in the icon class. I know the icon class doesn't have access to any of myFrames methods or instance fields, so how do I correctly implement this. Surely the answer isn't to bung all the code together into one class?
visually what I have so far looks like this
SERVER <---Requests---> myFrame --------> IconList ---------> Icon
the IconList class looks up a server to update its array of Icons[]. But when one individual Icon is clicked on myFrame, i want its mouseListener to load some of its values onto myFrame's GUI components.
I hope I'm making myself clear, im sorry if this seems like a muddled incoherent question, but any advice would be great. I only need to be shown the correct way to design, and then i carry on coding happily. If this kind of design is way off, please let me know!!
Thanks

You can absolutely do work on the frame from the mouse listener--It just needs an instance. i.e.
public class MyMouseListener implements MouseListener {
private MyFrame frame;
public MyMouseListener(MyFrame frame) {
this.frame = frame;
}Does that make sense?
That said, what you'll see more often is a Model-View-Control approach, wherein the Control (the mouse listener in your case) effects the Model and the Model notifies the View to update its display, rather than the Control updating the view directly. That's the extreme overview version, lots of good hits on google if you're interested beyond that

Question about Object Oriented Design in Oracle

Hi everyone,
Right now I'm updating my oracle skills, years ago without programming (last time with Oracle 7.3 :O)
Well, if I have to design a new system with this features:
1.- Using Oracle as DB
2.- Web enable
3.- OO Design
My questions:
1.- What is the best practice to make database design? E-R + Object Types? I mean is better making the design on Oracle directly or in Java-UML environment?
2.- I was thinking in programming with Forms, but it works well with OO design?
3.- If I want to program some web services based, Could I do it with PL/SQL and Jdeveloper?
please if you know about articles and whitepapers about OO design approach with Oracle let me know!
Thanks.

I have been involved in some of these projects that have used Java, C#, VB, C++ etc. as front-end languagaes. I have been able to implement these projects successfully using the following approach:
1. create a relational model of the database - third-normal form (assuming it is an OLTP application)
2. Write PL/SQL code (packages and procedures mainly)
3. Interact with the front-end layer by sending and receiving ref curosors and/or PL/SQL tables
If you want to use Forms (I am assuming Oracle Forms) then there may not be much need for an OO design. Embeeding SQL in the forms will do most of what you want.
Shakti
http://www.impact-sol.com
Developers of Guggi Oracle - Tool for DBAs and Developers

Question about RADIUS server configuration with a MacBook Pro

Hello,
I own a modem router which is capable of WPA2 Enterprise and I want to use it with a RADIUS server for authentication and security purposes.
However, I have a few doubts about this.
MY CONFIGURATION:
The modem router would be connected to a fixed PC with Windows and to a MacBook Pro (both with Ethernet)
The RADIUS server would be running on the MacBook Pro (freeRADIUS)
The bold is the issue, that comes when I disconnect the MBP (it's a notebook, so I use it disconnected from the router sometimes).
Supposing the router would have recognized it (correct configuration), it would disconnect from it.
My questions:
Would Wi-Fi be lost in this manner? Or would the modem router automatically switch to another Wi-Fi authentication?
If I reconnected the MBP to the modem router and re-run the RADIUS server, would I need to access the control panel and re-configure the WPA2 Enterprise in order for Wi-Fi to work again?
Thanks in advance,
Tyrexionibus

"Full HD 3DD camcorder..." Marketing at it's best.
This is HDV, right? HDV has the same data rate as DV...13.6GB/hour. But because of the MPEG-2 Long GOP format the HDV format employs, it can be a bit tough to edit, but mainly when rendering effects. IT will be slower than DV, and you can't monitor thru the camera like you can with DV, but a simple FW400 drive and Intel Mac will be fine. Better if you can convert to ProRes upon ingest, but then that eats up a LOT more space and requires at least FW800...
http://library.creativecow.net/articles/poisson_chris/hdv-prores.php
Shane

[SOLVED Noob question about web server permissions

Hi I have setup up succesfully my web server. Now I am having some permission's questions/problems.
First of all, I want the /home/httpd/home folder not to be show to the other machine users and only to root.
I have created a user www-data and I have conf the apache file.
This is my settings:
My server directory is: /home/httpd and the permissions I have set:
home dir:
~edited because solved~
I have set .htaccess to some folders. I don't know If the permissions are safe or not. Can you help me?
I think that I have different permissions to files and different to the folders...
Thank you!
Edited:
And an example of my permission (phpMyAdmin):
~edited because solved~
Last edited by k3rn31 (2008-02-28 22:26:09)

This is more of a chat item for me, if you feel like it you can find me most of the time here at http://zaxter.org/xmpp.html if you have flash you can join via a simple click on connect.
Sorry I've not been of much help to you.

Question about client/server design

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