Registry level counters in Linux accessible from Java - c#

I am looking for counters in Linux systems similar to custom counters in Windows, which could be accessed through C#. (http://msdn.microsoft.com/en-us/library/aa326924%28v=vs.71%29.aspx). My use case is this: I have a process that imports a file from location A to B. This file has some XML records that need to be parsed and loaded into a database. I want to have counters which I can keep incrementing, for example, whenever a new file is received at B, and whenever a record is imported into the database. I want to log these counter values at regular intervals to detect any inconsistencies. I used to do this with custom counters (refer to the link above) when I was using Windows+C#, but how can I do this in Linux+Java ?
Thanks for any help..

Linux doesn't have a registry (thank goodness) I wouldn't suggest you mix application data with your OS. Java has User preferences, but I don't recommended you use it for this type of information.
If you want to record some information, write it to a file, or database e.g. http://java-sources.net/open-source/database-engines A file might be the simplest.

The real win with creating a custom counter in a Windows application is that you can monitor your application at runtime using the Windows Performance Monitor. So in your example you could watch how the number of files received over time changes.
The "Java way" (i.e. platform independent) of doing something simillar is JMX.
By all means write the values to a file or database as Peter suggests. That will give you a historic view of the stats. But I strongly recommend you investigate JMX as a way of monitoring your application at runtime analogous to Windows counters.

Related

How to write a window service that track the number of times a specific folder was Opened

I Hope that this is the Correct way of asking this question. first my problem is that i want to know that how many times a specific folder was opened from the time my windows service start's. I don't want to write a desktop application for this purpose because i want it to happen in the background and also later i may want to add some more functionality. So that is why i need to be it a windows service.
is there some kind of OS Event that i can handle during my code, i.e the event is fired when a user open's folder.
If this is not the correct method then please let me know some other method that can help.
That's not possible in C#. You can be notified of changes within a directory and infer from that that the directory was opened--but there are many times when a directory is opened and nothing will be changed. What you're describing is most like a File System Filter Driver.
From What is a File System Filter Driver:
A file system filter driver can filter I/O operations for one or more file systems or file system volumes. Depending on the nature of the driver, filter can mean log, observe, modify, or even prevent.
Writing a filter is relatively easy, considering there are templates that you can use to base your work from. But, they do consist of kernel-mode code meaning they're not written with C# (they are typically written with C) and they are drivers.
for more details: http://msdn.microsoft.com/en-us/library/windows/hardware/ff540382(v=vs.85).aspx

How should I set this project up in .NET?

I have a unique set of processes that all need to be automated.
We receive very inconsistent data from our customer so this requires a lot of responses from not very computer literate users. I'de go with console if it wasn't for that.
That data needs to be transformed and then combined using a few different processes.
I need to create an application that can only be accessed from one person at a time (we don't want to have multiple people building the same data).
All processes can be run on one machine.
A basic outline is the following...
Get all of the zip files from our customers FTP
Unzip all of these files into the specified directory
Take this data and verify it's surface level integrity
Transform the data to a new format
Import to the database
Build documents based on the data
I know how to write each of these functions, my question is more: should I do this in MVC3 with AJAX updates, WPF, windows forms, or straight asp.net? I know all of them, I just can't think of which fits this linear processing scheme. The user also needs constant updating of progress on each file so any of the asp.net derivatives get tricky with ajax.
I'd recommend just making a console application. Do you need an interface?
Two options: a console application to be launched as a scheduled task, or a Windows Service.
If everything is automated I would create a windows service to do everything. By doing so you'll also prevent the application from being run by more than once simultaneously (unless you install it on several computers).

ASP.NET, log file and database - need tips

I'm planning to develop an application that will read a log file and display statistics.
The first question, I guess, is to know if I need a database or not?
Will it be quicker to run queries against the database ; or read the file each time a user wants to see the statistics?
If I choose the database method, I will have to read the log file and update the database on a regular basis (between 1 and 10 minutes).
Is this article still good do you think (as it's from 2005): http://www.codeproject.com/KB/aspnet/ASPNETService.aspx
Or is it better to develop a Windows service? In that case, can I add the Windows Serice in my ASP.NET project in Visual Studio, or does it need to be
You mentioned ASP.NET so I believe it is a web application. In such case I would suggest to use Data Base, this is more robust, flexible and distributed solution.
Any way consider using log4net and then you can easily switch on file/DB ouput in any time by simply adding an other one appender section into the configuration file.
If I choose the database method, I will have to read the log file and
update the database on a regular basis (between 1 and 10 minutes)
Exactly, you're going to have to do it anyway. The Database basically just becomes another bottleneck at that point. For this type of app, there's no need to do anything other than read the file when the user requests to see it, and display them the results on the fly.
No need to have a windows service either. I mean, I don't know all your details, but I'm assuming the log file is in a directory on your machine, so just access it, open it, parse it, and display it to the user when they choose to see it on the front end.
If the only data you going to work is LOG files, you don't need any database.
But I assume that your application would do parse logs files, create some statistics and STORE it somewhere, to make possible to users to get back and see statistics for some period of time. It is not cool if any time you will be "re-calculating" that statistics again (further more, you might loose original log files till that time).
Even if you could store it to some files also, I do not recommed that at all. Don't be afraid of using Database, don't be concered on application performace on such early stage. Do the most that helps you to solve the problem.. and as for me using Database will solve your problem;

Store the state of a variable in C#

I am working on a c# application that is serially encrypted when user install the application and runs application first time I ask user for key and if he enters right key. I run the application. But my requirement that this process should be one time after installation only,
I think there are two possibilities.
Store software validation state in a variable and use it to allow the running of application (I do not want to use XML,Object serialize as I have to save the state of one variable also user can remove files created by serialize).
Ask user about key while he is installing application,If he enter wrong key then he should not be able to install the software.
Can some body answer
Is there a simple way to store the state of a single variable.
Or
2. How to trigger installer manually (after validation).
Software Protection is an old and expansive topic. The current state of the art, is that it's not really possible to protect you software 100% reliable. Sooner or later, someone will crack it anyway, given enough exposure and/or interest.
Nonetheless, a lot of people and companies protect their software products and there are a number of way to this (not 100% reliably however).
It is not clear what your requirements are, from your question. Given what you've described, the simplest option would be to zip up the installer with a password. If a user don't know the correct password they won't be able to unpack the zip file and install your program.
This is usually not very practical, as the same password is provided for everyone. You want to do your own serial key validation, and you considering doing this at installation time. If this is the route you want to go for you will need to provide some script that will do validation to your installation system. You indicated, that you are using windows installer. You can user Windows Installer XML (WiX) toolset to author an installation. Given enough patience, you can built the key validation into your windows installer package. Most practical way possible is to call your validation routine that you've writen in c# from the wix package. You can use Conditional Syntax to check conditions in your installation. This should cover your option 2.
As for option 1, then whenever in the system you store your piece of information, user always will be able to get there and change it (it's their computer after all). Some people store this in registry, some in key files. Deleting these files is usually not a problem, because if user deletes them, your program will know that it should not run. However a user would be able to copy them on other machine, etc.
Isolated Storage is yet another place to store you information with .NET. Ultimately it is some deeply buried files in the file system anyway.
Once again, Software Protection is a complex topic, it's up to you to decide, what you requirements are, what compromises you can afford and what you choose to implement.
Good luck!
for something like this, i would encrypt it and store it in the registry. this is not they type of thing that you want to store in a settings file. you can check out this codeproject article on how to access the registry using C#.

Patch an application

I need to create a patching routine for my application,
it's really small but I need to update it daily or weekly
how does the xdelta and the others work?
i've read around about those but I didn't understand much of it
the user shouldn't be prompted at all
Ok this post got flagged on meta for the answers given, so I'm going to weigh in on this.
xdelta is a binary difference program that, rather than providing you with a full image, only gives you what has changed and where. An example of a text diff will have + and - signs before lines of text showing you that these have been added or removed in the new version.
There are two ways to update a binary image: replace it using your own program or replace it using some form of package management. For example, Linux Systems use rpm etc to push out updates to packages. In a windows environment your options are limited by what is installed if you're not on a corporate network. If you are, try WSUS and MSI packaging. That'll give you an easier life, or ClickOnce as someone has mentioned.
If you're not however, you will need to bear in mind the following:
You need to be an administrator to update anything in certain folders as others have said. I would strongly encourage you to accept this behaviour.
If the user is an administrator, you can offer to check for updates. Then, you can do one of two things. You can download a whole new version of your application and write it over the image on the hard disk (i.e. the file - remember images are loaded into memory so you can re-write your own program file). You then need to tell the user the update has succeeded and reload the program as the new image will be different.
Or, you can apply a diff if bandwidth is a concern. Probably not in your case but you will need to know from the client program the two versions to diff between so that the update server gives you the correct patch. Otherwise, the diff might not succeed.
I don't think for your purposes xdelta is going to give you much gain anyway. Just replace the entire image.
Edit if the user must not be prompted at all, just reload the app. However, I would strongly encourage informing the user you are talking on their network and ask permission to do so / enable a manual update mode, otherwise people like me will block it.
What kind of application is this ? Perhaps you could use clickonce to deploy your application. Clickonce very easily allows you to push updates to your users.
The short story is, Clickonce creates an installation that allows your users to install the application from a web server or a file share, you enable automatic updates, and whenever you place a new version of the app on the server the app will automatically(or ask the user wether to) update the app. The clickonce framework takes care of the rest - fetching the update , figure out which files have changed and need to be downloaded again and performs the update. You can also check/perform the update programatically.
That said, clickonce leaves you with little control over the actual installation procedure, and you have nowhere close to the freedom of building your own .msi.
I wouldn't go with a patching solution, since it really complicates things when you have a lot of revisions. How will the patching solution handle different versions asking to be updated? What if user A is 10 revisions behind the current revision? Or 100 revisions, etc? It would probably be best to just download the latest exe(s) and dll(s) and replace them.
That said, I think this SO question on silent updates might help you.
There is a solution for efficient patching - it works on all platforms and can run in completely silent mode, without the user noticing anything. On .NET, it provides seamless integration of the update process using a custom UserControl declaratively bound to events from your own UI.
It's called wyUpdate.
While the updating client (wyUpdate) is open source, a paid for wybuild tool is used to build and publish the patches.
Depending on the size of your application, you'd probably have it split up into several dll's, an exe, and other files.
What you could do is have the main program check for updates. If updates are available, the main program would close and the update program would take over - updating old files, creating new ones, and deleting current files as specified by the instructions sent along with a patch file (probably a compressed format such as .zip) downloaded by the updater.
If your application is small (say, a single exe) it would suffice to simply have the updater replace that one exe.
Edit:
Another way to do this would be to (upon compilation of the new exe), compare the new one to the old one, and just send the differences over to the updater. It would then make the appropriate adjustments.
You can make your function reside in a separate DLL. So you can just replace the DLL instead of patching the whole program. (Assuming Windows as the target platform for a C# program.)

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