I am curious about relaying messages from one app on one machine to another machine. I have a shared network storage readily available to me. My thought is that I want to run an app on a single machine that runs intranet uploads. I cannot control anything about the domain or the shared network storage other than creating files/folders.
I want this app on its own machine to be able to report somehow to a completely different application installed on completely different user machines (so in case of errors lets say, users could intervene) and at some point, across platforms (vb.net/Access/etc).
The first thing that hit me was to stream write the upload app's status to a text file, and then have a timer on my users end app that monitors the file that the upload app writes to.
However, before implementing, I am wondering if I am reinventing the wheel, and theres a better way to do this. I am seeking simple solutions, and eventually I would like to integrate this into VBA/Access. What does SO think fits the bill? What is the downside to streaming a "log"?
You're reinventing the wheel. This is Message Queuing. There are many existing solutions to do this, including MSMQ (built into Windows) and RabbitMQ. There are also cloud based services like Azure AppFabric and Amazon Simple Queue Service.
Related
I am trying to build a middleware application ( you know...retrive data from a webservice and store to db in cPAnel and send the data to the webservice hosted from here)
Is it possible to run an application in cPanel?
If it is possible what is the prefferedlanguage for this purpose and
why?
If I am trying to run an application which has to update this fetch
hourly automatically form code.is it possible.means i want this
application to be in running state for an indefinite time.Is it
possible?
My thoughts are:
1. cPanel is not a jumping off point for applications. It is simply a shared hosting management console. It gives you the ability to do some management. You can fire off applications by making a cronjob.
Generally you have two choices, you can use shell scripting or PHP invoked from a shell.
Now this narrows it down further. PHP is configured to have a maximum execution time to stop people hogging the processors.
If you are going to write some proper middleware, I'd suggest that you either get yourself an Amazon, Jelastic or some other cloud hosting provider. You will get the ability to deploy a real application, on a full operating system - rather than "hacking" a solution.
cPanel based installs are really for those people who just want to put a website, whack up a blog, or do some low bandwidth hosting. Running something constantly is going to have you violate the terms of service on these accounts very quickly.
We are currently planning to develop a suite of Windows Store Apps. They are independent and fully work alone, but they are related and act in concert. If a user has several of them, they should share some of their settings (and data), so that the user does not have to manually change these settings in every single one of them.
Is such a scenario even intented?
And how to implement it?
Registry: Does not work. Apps cannot access the registry.
ApplicationData (LocalFolder, LocalSettings etc.): Does not work. Apps cannot access the data of other apps.
Cloud services: Kind of works, but only when the machine is online. Our apps should work offline, too. And we would need to create/rent such a cloud service, which would cause additional costs.
KnownFolder.DocumentsLibrary: This –currently– looks like the only solution to me. The apps are already saving and sharing data there, so let's just save our settings there, too. But the name of the shared folder is one of the settings! And Windows Store Apps cannot create hidden files, so the user can see the settings file. This makes this solution a bit... "rough".
Any other ideas or additional information I have missed?
If you want them to sync with each other instantly, even when the device is offline, then that's your only option. Windows 8 Apps are not intended to share settings.
So much want of sharing.
Roaming API will only share with the SAME app, the SAME user, ANY W8 device.
SkyDrive will only share across ANY app, the SAME user, ANY device.
Using Azure (or any web service) will share across ANY app, ANY user, ANY device.
Don't do this
Don't use the register, the API is not supported
Don't use the file system, the boundaries cause your app to be brittle
Don't use ApplicationData.AnyFolder, this is restricted to a single app GUID
You had might as well get "instant" out of your language, man. That just doesn't happen. But you can have fast (let's call it near instant); you can use Sockets or SignalR to connect your client to some service out there with nearly instant responses. A less sophisticated approach would be to poll from your client, too. It has served developers for decades.
I am in the process of integrating our custom web app with QuickBooks Enterprise 9. My thought is that I could use QuickBooks as my "database" of sorts. When a person creates an invoice, the invoice is actually stored only in QuickBooks. When a person views a list of invoices, they are actually viewing a list of QuickBooks invoices. I want to make sure the data is stored in only one location.
I realize that I could use the QB Web Connector, but the problem with that is I wouldn't have control over when the requests to QB actually get processed (That job is up to the Web Connector).
So I have my web UI to act as the QuickBooks "face," but I don't have any good way to get to and from the QuickBooks file located on an internal server. What I was thinking was that I could create a WCF web service and install it on the QuickBooks server. The web service could then be my integration point. My custom web app could then consume the web service and, viola, I have access to my QuickBooks files.
My question is this: Can a WCF app connect and run QuickBooks? If not, could i create a Windows service to act as my point of integration? If so, can my custom web app "consume" a windows service?
I'll start by warning you that QuickBooks probably isn't your best choice for a reliable back-end database accessible from a remote website. In fact... it's probably a really, really bad choice.
You should have your own application database, and then if you need to also exchange data with QuickBooks, do that outside of the normal lifecycle of your app, as a separate sync process.
QuickBooks generally isn't reliable enough for always-online type of applications due to a number of reasons:
Flaky SDK connections
Updates and single-user mode will
lock you out of accessing QuickBooks
Difficulty in establishing SDK connections from non-GUI processes (Windows Services and IIS processes)
With that said...
Yes, you could create a WCF web service, host it on the QuickBooks machine, and make your WCF web service relay messages to/from QuickBooks.
Yes, you could also create a Windows Service that does the same sort of thing.
Do NOT implement it as a Windows service, and do NOT implement it within IIS - instead implement it as a GUI app that runs alongside QuickBooks.
If you try to implement things as a Windows service or within IIS, the QuickBooks SDK requires you have a GUI available (it users a GUI COM message pump for events dispatching or something like that...) to process requests, so you'll probably need to use something like QBXMLRP2e.exe to straddle the process boundary between QuickBooks and your non-GUI Windows service/IIS. My experience has been that it's a gigantic pain in the butt, and requires mucking with DCOM permissions as well.
I have an example and some documentation on my QuickBooks integration wiki.
The IDN Forums are a good place to ask questions.
My recommendation to you would be to either:
Use the Web Connector and QuickBooks
and give up hope of keeping all of your data in one place. Cache the data in a real database, and update it by querying QuickBooks periodically. I'm almost done building a solution to do exactly this right now, and it works fantastic.
OR
Use a different account system. NetSuite is pretty nice. I'm not sure what else is out there, but if I were you I'd look for something SQL-based or with a strong SOAP/REST API.
I have several different c# worker applications that run various continuous tasks: sending emails from queue, importing new orders from website database to orders database, making database backups and restores, running data processing for OLTP -> OLAP, and other related tasks. Before, I released these as windows services, but currently I release them as regular console applications. They are all based on a common task runner framework I created, and I am happy with that, however I am not sure what is the best way to deploy these types of applications. I like the console version because it is quick and easy, and it is possible to quickly see program activity and output. The downside is that the worker computer has several console screens running and it gets messy. On the other hand the service method seems to take to long to deploy and I have to go through event logs to see messages. What are some experiences/comments on this?
I like the console app approach. I typically have things set up so I can pass a switch like -unattended that suppresses the console screen.
Windows Service would be a good choice, it runs in the background no matter if you close current session, also you can configure it to start automatically after windows restart when performing a patches update on the server. You can log important messages to event viewer or database table.
For a thing like this, the standard way of doing it is with Windows services. You want the service to run on the network account so it won't require a logged in user.
I worked on something a few years ago that had similar issues. Logically I needed a service, but sometimes I needed to see what was going on and generally I wanted a history. So I developed a service which did the work, any time it wanted to log, it called to it's subscribers (implemented as an observer pattern).
The service registered it's own data logger (writing to a database) and at run time, the user could run a GUI which connected to the service using remoting to become a live listener!
I'm going to vote for Windows Services. It's going to get to be a real pain managing those console applications.
Windows Service deployment is easy: after the initial install, you just turn them off and do an XCOPY. No need to run any complicated installers. It's only semi-complicated the first time, and even then it's just
installutil MyApp.exe
Configre the services to run under a domain account for the best security and easiest interop with other machines.
Use a combination of event logs (with Error, Warning, and Information) for important notifications, and just dump verbose logging to a text file.
Why not get the best of all worlds and use something like:
http://topshelf-project.com/
It will allow you to run your program as command line or a windows service.
I'm not sure if this applies to your applications or not, but when I have some console applications that are not dependent on user input or they are the kind of applications that just do their job and quit, I run such programs on a virtual server, this way I don't see a screen popping up when I'm working, and virtual servers are easy to create and restart.
We regularly use windows services as the background processes. I don't like command-line apps as you need to be logged into the server for them to run. Services run in the background all the time (assuming they're auto-start). They're also trivial to install w/the sc.exe command-line tool that's in windows. I like it better than the bloat-ware that is installutil.exe. Of course installutil does more, but I don't need what it does. I just want to register my service.
We've also created a infrastructure where we have a generic service .exe that loads .DLLs based on an interface definition, so adding a new "service" is as simple as dropping in a new DLL and restarting the service host.
However, we started to move away from services. The problem we have with them is that they lock up the DLLs (for obvious reasons) so it's a pain to upgrade them. We need to stop, upgrade and then restart. Not hard, but additional steps. Instead we're moving to special "pages" in our asp.net apps that run the actual background jobs we need done. There's still a service, but all it does it invoke the asp.net pages so it doesn't lock up any of our DLLs. Then we can replace the DLLs in the asp.net bin directory and normal asp.net rules for app-domain restart kick in.
I've created a service for one of my apps. How do i create a system tray component in VB.net that can be used to monitor the progress of the service? Is there a way to have this installed via tcpip on multiple client machines such as those that are for our employees?
We do exactly that here, with the server running a really basic HTTP server on a configurable port on a separate thread that returns status in an XML format (nothing else, just that) -- the client just uses a web request to get the XML, before parsing it and displaying it appropriately.
This approach also allows for future extensibility (detailed status, sending service control commands, adding an association to an XSLT file elsewhere for use with a normal web browser, etc.)
You could use WCF for this. Using WCF your service would open up an EndPoint which would expose status information to callers. You could then build a tray icon application that can be deployed to the employees workstations. The tray icon application could periodically poll the WCF service the your Windows Service is hosting and get status information. I know #Johan mentioned Remoting already and this is a similar approach. I'd recommend WCF though as the programming API is more simple, IMHO, and WCF will give you more flexibility with regards to network transports, etc.
I guess your question is not about how to actually do the "traybar"-thing, but how to communicate with the service to get the information you want to show in the monitor/traybar-program?
It can be done in many ways, API is one way, use sendmessage/postmessage/getmessage is one way to make 2 running programs communicate with each other without having to store anything in files or databases first.
DDE is another way. If it needs to do the stuff via net then there is something called NetDDE, but I havent done anything with NetDDE I cant help anything there.
But about the API and DDE, feel free to ask more questions if you want some clarification.
I'll take the second question: Is there a way to remotely install software on client machines?
Yes. However it is very dependent on your environment. For example, if you have an Active Directory domain, you can use group policy to force installation of software on the client boxes.
If you don't like that or if you aren't on active directory, you can buy something like Altiris to push installs down.
Another option would be to use login scripts which would run a custom program to detect if your program is installed and take appropriate action. But then you are probably better off buying Altiris.
For the comunication part, i have used remoting before, and this works very well. With a little bit of configuration, you can even get it working to another machine.