I am experimenting AsyncController feature. What I did is set up two tasks to run in parallel. As in the code below, the problem is that sometime all tasks finished and return successfully, sometime only one task finish and sometime each task finish half of it's work and return. It is weird, what did I do wrong?
[Code]....
I try to get an understanding of the performance of a web page and use Trace.Write
Problem is that I use Parallel.Invoke and starts more threads where I would like to report back using Trace.Write
Parallel.Invoke(() => Chart1AndLegend(param),
() => Chart2(param),
() => Chart3(param),
() => Chart4(param));
I have realized that Trace.Write is not a good way of tracing as it is gives you the time since last entry which makes no sense if more threads are writing.
I've got a WCF web service that runs fine at the moment but there is talk about using it very heavily soon. As part of it's normal process it writes a file out, then reads it back in again (don't ask why, I know it's stupid). I'm concerned that if we start hitting it with lots of requests then the following might happen.
1. Request 1 writes the file out.
2. Request 2 comes in and overwrites the file.
3. Request 1 reads the file back in but this is now the wrong file.
My understanding is that the requests would naturally queue up so that request 2 wouldn't start until request 1 had finished, but I'm not totally sure.
I have just started to look at the new "System.Threading.Tasks" goodness in .Net 4.0, and would like to know if there is any build in support for limiting the number of concurrent tasks that run at once, or if this should be manually handled.
E.G: If I need to call a calculation method 100 times, is there a way to set up 100 Tasks, but have only 5 execute simultaneously? The answer may just be to create 5 tasks, call Task.WaitAny, and create a new Task as each previous one finishes. I just want to make sure I am not missing a trick if there is a better way to do this.
[code]....
This is my first forray into ASP.NET MVC, having been doing WebForms for nearly 6 years now. I've read through various tutorials and guides on getting started with MVC, but I've a few questions about how you're meant to do things:
UserControls for entities
In an application I wrote a few years ago (using WebForms) there were many entities that had an associated postal address (which existed as an instance of an Address class), so I created a UserControl that contained fields for working with addresses. During the page lifecycle I would pass the business object's .Address property to the UserControl for display and for population upon a successful and valid postback. How would I do something like this in MVC? My current project has a similar situation where common sets of fields are repeated throughout the application and all 'map' to the same class.
Modifying the page/view on 'postback'
Say I'm working on a data-entry form for an online B2B ordering system, where the user manually enters order items into a series of textboxes arranged in a table. The system can only provide so-many textboxes at a time (usually 5 or 10). If the user ran out of textboxes they would click an "Add more rows" button that performed a postback that was caught by that button's server-side .Click event handler. The page's class would then add more rows to the page; ASP.NET's stateful nature made this easy to implement. But in MVC there is no ViewState and I haven't found much information about how you'd do this, or anything like this. All of the tutorials and guides assume a form posting is only for data submission.
Multiple tasks per page/form
In a similar vein to the above, how do you create views that perform multiple tasks? In my above example I cited a webform that had two buttons: one to submit the form for actual processing, and another button that just modified the page (by adding more data-entry rows).Given that Controllers' actions are bound to URIs rather than what combination of fields were submitted, does this mean that I would have to interpret the posted data myself and branch based on that?
Componentised self-contained controls (e.g. sidebar forms)
Finally, in many web applications you have the main form in the middle, but also things on the periphary of the page (e.g. a sidebar) that might have their own logic. For example, in one WebForms application I wrote last year there was a 'Quick contact' form in a UserControl located elsewhere on the page. When the user clicked the form's button the UserControl's logic handled the postback details independently of the page containing the UserControl (but there was only one <form> element in the whole rendered page). The user was returned to the page they clicked the button on, with everything in identical state as to how it was before, exccept for the UserControl which reported that the email was sent. Again, MVC's stateless nature would make something like this hard to implement, unless there are some techniques not covered in the tutorials?
In my ASP.NET MVC2 web app I have a page which goes off and gets results from a number of different web service feeds. These return times vary so I want to basically display them as they return after the page loads. I also want my user to be able to kick of requests that can run concurrently with these other requests.
At the minute my page just seems to queue up the requests. The web service calls returning one at a time in the order they are called and then the user can kick of requests.
Is this a case for the asyncController or is there an easier/better way of working this?
Frameworks like Node.js, Tornado, and Twisted let developers create server-push applications that supports large number of concurrent hanging requests (10k+). From what I understand, they all achieve this by not creating threads to service each hanging request.
Can AsyncController be used to service large number of inactive concurrent requests?If so, are there any reasonably large ASP.NET MVC websites using this approach to create long-poll applications?
Does anyone have a working pattern for converting a GET-POST-GET pattern to asny?
I'm encountering the following issues:
1. You cannot mix Sync and Async action methods SubmitForm(), SubmitFormAsync(bool? confirm), SubmitFormCompleted() ... (because the resolver gets all confused ... it doesn't use the HTTP verb to decide who to target. BTW: I think that's poor design, or a bug)
2. Renaming the get method name to something else eg: SubmitFormConfirmation(), SubmitFormAsync(bool? confirm), SubmitFormCompleted() would be very awkward if it works ... because you have to doctor the <form markup to specify an action name.
3. You cannot give them all async names SubmitFormAsync(), SubmitFormAsync(bool? confirm), submitFormCompleted(), because the call just keeps malfunctioning. It sometime even behaves as if you are requesting a delete of something.
Can someone give an insight from an actually working sample.
Let's imaging there are 2 pages on the web site: quick and slow. Requests to slow page are executed for a 1 minute, request to quick 5 seconds.Whole my development career I thought that if 1st started request is slow: he will do a (synchronous) call to DB... wait answer... If during this time request to quick page will be done, this request will be processed while system is waiting for response from DB.[URL] One instance of the HttpApplication class is used to process many requests in its lifetime. However, it can process only one request at a time. Thus, member variables can be used to store per-request data.Does it mean that my original thoughts are wrong?Could you please clarify what they mean? I am pretty sure that thing are as I expect...
View 2 RepliesI have windows service which need to execute around 10000 schedules (need to send/execute data to all the members).
For one member it's taking 3 to 5 seconds for 10000 schedules it's taking around 10 minutes or so..
But I need to execute all these schedules in one minutes.
I have a method that I call 8 times with different parametres.I use
AvailableYears.AsParallel()
.Select<Int32,DateUsedByThread>(x => GetDataForYearWorker(x,CIF))
.ToList();
GetDataForYearWorker gets the response from a webservice synchronously. It uses very little computing power on my asp.net application, but it ussualy takes 3-5 sec for each webservice response. Because the calls to the webservice are independent of eachother, I want to make tham all at the same time. But it looks like only 2 threads can run at the same time. Why is this and how can I have 8 threads working at the same time?
It seems that by default, ASP.NET 3.5 running on IIS 6.0 does not do any parallel processing whatsoever. With a quad-core system and a test webforms application that runs an infinite while loop on the server, CPU usage never goes higher than 30% regardless of how many clients are connected and independently running the while loop.What are my options for enabling parallel processing?
View 2 RepliesWe are using 6 iFrames on our page. They fetch data from couple of external web services and an internal WCF service and display the data. There is a separate aspx page built for each of the iFrames. From our perf monitoring we found out that at any point only two threads are executing in parallel. Not all 6 threads get executed. What can probably be cause for this? Is there any restriction that more than 2 threads can't be created in parallel? Is there any configuration where I can change this?
View 3 RepliesI'm working on an ASP.NET MVC application that uses the Google Maps Geocoding API. In a single batch there may be upto 1000 queries to submit to the Geocoding API, so I'm trying to use a parallel processing approach to imporove performance. The method responsible for starting a process for each core is:
public void GeoCode(Queue<Job> qJobs, bool bolKeepTrying, bool bolSpellCheck, Action<Job, bool, bool> aWorker)
{
// Get the number of processors, initialize the number of remaining
// threads, and set the starting point for the iteration.
int intCoreCount = Environment.ProcessorCount;
int intRemainingWorkItems = intCoreCount;
[Code]...
This is based on patterns document I found on Microsoft's parallel computing web site. The problem is that the Google API has a limit of 10 QPS (enterprise customer) - which I'm hitting - then I get HTTP 403 error's. Is this a way I can benefit from parallel processing but limit the requests I'm making? I've tried using Thread.Sleep but it doesn't solve the problem.
Currently we are developing an ASMX, ASP 2.0, IIS 7 web service that does some calculations (and return a dynamically generated document) and will take approx. 60 seconds to run.Since whe have a big machine with multiple cores and lots of RAM, I expected that IIS tries its best to route the requests that arrive in its requests queue to all available threads of the app pool's thread pool.But we experience quiet the opposite:When we issue requests to the ASMX web service URL from multiple different clients, the IIS seems to serially process these requests. I.e. request 1 arrives, is being processed, then request 2 is being processed, then request 3, etc
View 2 RepliesI have a static class with a static get property, and in this property, I do this:
// property body
{
// HttpContext.Current is NOT null
Parallel.ForEach(files, file =>
{
// HttpContext.Current is null
var promo = new Promotion();
});
// HttpContext.Current is NOT null
}
This static class doesn't undergone type initialization until a view uses this property.
The problem is that Promotion's static constructor, which is initialized the first time a new Promotion() is created within the Parallel.ForEach(), uses HttpContext.Current. When promo is instantiated within the scope of this Parallel.ForEach(), HttpContext.Current is null, and new Promotion() therefore causes an exception.
HttpContext.Current is not null within the static get property because it's not called until the view uses it (and there is therefore a HttpContext.Current).
If Promotion used HttpContext.Current in its instances instead of its static members, I could probably just pass HttpContext.Current into the new Promotion() constructor:
var context = HttpContext.Current;
Parallel.ForEach(files, file =>
{
var promo = new Promotion(context);
});
But since static members of Promotion need HttpContext.Current, I can't. I could probably redesign the Promotion class to change the static members that need it to be instance members, but they are static for a reason--there would be a large performance penalty if all the members that were static had to be defined instead on each instance each time a new Promotion was instantiated.
What are the possible workarounds for this? I didn't realize HttpContext.Current would be null within the scope of Parallel.ForEach().
I am seeking your expertise in ASP.Net with regards to multi-thread support of WebService in a scenario , that is If a WebService-Client is making simultaneous calls from the same process, the requests will be serialized at the WebServices so that only one-call will execute at any one time , on the contrary, if those calls are sent from different WebService-Clients ( Instances/Processes) , they are processed in-parallel by WebServices.
Have you ever experienced the same with ASP.Net, and what configurations/Settings should be followed, in order for a WebServices to concurrently process simultaneous calls form a single WebClient , when deploying a large number of Web-Clients' instances/processes is impractical in a project-context.
I've got about 30 projects in VS 2008 and we are finally starting to upgrade to 2010. I get change requests pretty regularly so I'm likely to have to make changes to projects that are still in 2008 after VS 2010 is installed. Is it possible to intall VS 2010 without messing up the VS 2008 install? If so is there any particular trick to it so they live side by side or do they automatically do parallel install in different directories?
View 3 RepliesWhen I serve an ASP.NET page, can I render the various controls on the page in parallel?
I have a few Telerik controls (RadGrids) on the page and when I step through the page being loaded, it seems as though the controls are databound and rendered serially.
Maybe this behavior is because I am hooked in with the debugger.
Is there anyway to load the page and have select controls build on separate threads? Is that even conceptually possible or must it be done sequentially?
On our webform, I do I remove the vertical lines parallel to each field column?
Visit the webform at [URL]
View snippet code, below:
[Code]....
I am a beginner of C# programming. I have read a few books about C#.net. But I cannot find some exercises in the books. Someone told me to build up a blog to practice my coding.
But it is a huge task for a beginner. I just want some tasks to have a step by step learning process.
I used Castle Windsor before and had this routine that fired the certain method of all classes that implement a certain interface.If I recall correctly, the interface was IBootStrapTask and only had an excecute method. Then, for instance, I'd place all my route registrations in one of these, and know it get fired on application startup.Have to admit I did not understand the code to well, so I'm even more unsure how can I do this. I'm using structure map now. (still knowing very little about it)
View 1 RepliesI got a web page, it has a tabcontainer, within each tab, there will be a gridview, all the tabs and gridview are created at run-time, i have only one code, that I will loop through to create all those tabs and gridview. When I apply the sorting, and I click on the column name on any grid, it returned an error saying index was out of bound. BUT, when there is only ONE grid view created, it is working fine, I suspect it mixed up all the grid view's id and so on. But I have assigned different ID to gridview
View 8 RepliesI was just after some help to put the following code into a loop. I have 6 div's with id's ImgDetails1 - ImgDetails6 and 6 buttons
with id's 1 - 6
if 1 is pushed it should hide the other divs but ensure div1 is shown. the same applies for every other
div.
I can do this the long way writing logic for each div but I am not the best with js and have failed
at each attempt to put the code in a 1 - 6 loop to hide all divs except the one selected and make sure that is shown.
[Code]....
In my ASP.NET website, I am having a function which has to be automatically performed once every 2-3 mins on its own, i.e. without user intervention. This function contains database access.
Can I use threading to perform this process in background?
If Yes, How can I use that?
Edit
Also I am not looking for a solution which includes windows service because I am using shared hosting. So I dont have all the rights to access the host computer.