C# - Shared Messaging Queue For Multiple Worker Threads In IIS?
Nov 1, 2010
I'm currently trying to interface our new intranet (ASP-MVC) with the web front end of our pager system. The pager system's front end is about 10 years old, poor interface and no documentation. To do this I have the form on the intranet post to the server, our server then sends an HTTP POST to the pager server that mimics what its own form sends.
While testing this for overloading (we sent about 10 messages almost concurrently) the pager server crashed, as the system is a black box and the only difference we noticed was the concurrent POSTs the least we can do is try to prevent this happening.I want to have all messages go into a queue that sends at most once every 5-10 seconds but I'm not sure how to implement this,
I didn't specify this earlier but the process should be synchronous from the point of view of the browser, ie webserver gets the http POST request from the browser, message is put into the queue, message is sent from the queue, webserver sends http response to the browser. This is not a high volume service and I expect simultaneous requests to be rare so response will be near instantaneous, it is more of a throttle to prevent potential issues with concurrent requests.
since asp.net contains multiple threads that are executing at the same time.so if 2 threads access an object (simple or complex) that i got from the the asp.net httpcontext Cache.can't this lead to state problems on that object if these 2 theads tried to modify/read it at the same time?so what kind of precautions should i implement?for example i am thinking maybe locking the object while working with it? (wont this cause performance problems?)or maybe when i retrieve some object from the cache i should create a copy from it? or maybe i dont need to worry about this issue at all?
I'm investigating some performance improvements that can be made to our web server and ASP.NET application.This page contains a few things that we can do.We currently have two worker processes running as a garden. Do each of these worker processes have their own ASP.NET threadpool? Or do both of these worker processes share a single threadpool and the max number of worker threads is shared across these processes?This post seems to suggest that the two processes share a common ASP.NET threadpool. All w3wp.exe threads do is take requests from HTTP.SYS queue, process it, and hand the request toASPNET_ISAPI.DLL, who then deposits those requests into the ASP.Net request queue, and the ASP.Net threadsBut this post suggests that each worker process contains their own ASP.NET threadpool. Each process (w3wp.exe) has its own CLR thread pool which has the configured maxworkerthreads value (20 default).
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 a music related ASP.NET web site which caches a lot of static information from the database on the first request.Sometimes, the application is reset and cache is cleared while the application is on heavy load and then all http requests go to the database to retrieve that static data and cache it for other requests.
How can I ensure that only one request go to the database and cache the results, so that other request simply read that info from cache and not needlessly retrieve the same info over and over again.Can I use thread locking? For example, can I do something like lock(this) { db access here }?
Currently i'm developing an apllication that sends sms via the asp.net. I'm using msmq for the queuing incase of multiple sending of sms. The wcf will then check for new queue and using teh queue to send out a sms. I've a few question.How do i create a new queue for the msmq via asp.net
We are developing products that will be used in the following way:
Various shared libraries which may be used by multiple products. I anticipate these libraries will mostly need to access string resources that contain error messages/exceptions. Various end-user based applications, designed to run as standalone apps on a PC. They will be required to support multiple languages upon deployment/installation.
Various web-sites which may be required to support multiple languages either at deployment time or possibly at runtime (i.e. minimal or zero downtime). Potentially the site might need to support multiple languages at the same time if being accessed globally.
We may be required to allow customers access to our language files for editing themselves. We would not wish to allow them access to our source code (other than the resource files/dlls) in order to achieve this. We might need to incorporate a facility to log exceptions in our native language (English in this case) and display them in the translated language. This will us debug our customers solutions in the field.
I am already aware of products like RCWinTrans and handling multiple languages in VC++/MFC applications. However, the requirements we are faced with here are more extensive and thus require us to make a few up front decisions that could be difficult to change long term, so ideally we want to make the best choice now. Based on my own knowledge, I have a few questions although I may be missing some tricks with .net that will be happily received. Here are my questions:
What would be best? Put all our resources in a seperate DLL per VS solution OR put the resources in each VS project. The way I see it per solution is easier to manage, modify, and allow customer access. The per project solution seems cleaner though and makes the individual projects more portable. This method would apply to our shared library based solutions as well as our end-application based solutions.
Is it possible to have two seperate resource files loaded at once i.e. if we want to log the exceptions in English but supply them back up the food chain (as a message in an exception) in the translated language? Are there any tricks we can use to automate this like AOP?
I'm storing some value in an asp.net session on the first page. On the next page, this session value is being read. However if multiple tabs are opened and there are multiple page 1->page 2 navigation going on, the value stored in session gets mixed up since the session is shared between the browser tabs.I'm wondering what are the options around this :Query String: Passing value between the pages using query string, I don't want to take this approach since there can be multiple anchor tags on page 1 linking to page 2 and I can not rewrite the URLs of each tag since they are dynamic.Cookies??? In-memory cookies are shared across browser tabs too, same as the session cookie, rite ?
I have a website with auctions and i want to notify the winner. In a forum on my website users have an inbox and i want to send the message to there if they are the winner. Is there a way to message internally?
i am trying to add some functionality that will send alerts to people on a website.. for example... some action happens.. and triggers an alert on another users screen.. does anybody know of a messaging service that will listen for updates.. etc.. and popup some messages.. something generic that you could customize the messages would be nice..
i've just begun building a messaging system bit like the inbox feature in facebook and myspace. Its for my final year project. I was just wondering when a message is typed and the button "reply" is pressed, should the data go to the database? and then how can i display it like a thread on that page?
I was planning on handling the Session_OnEnd Event to check for new messages from other users in the database and display them, but the timeout value only works in minutes, not seconds. If there anything else that I can do to process an event every two seconds for a certain web page?
for years now I have had a problem with trying to design the best database design for an internal email messaging system for a website.
I would have thought that this would be a fairly easy thing to think of at this point in my development history but it still eludes me to no end.
What irratates me even more is that I would think i could find something online giving more detail about it but i have yet to find the right search term to use
Im creating a messaging system abit like the inbox feature of facebook and even this website (its gonna be created as a asp.net website). Now the messages ive been told should go to a database and then from there be displayed on a page. Im gonna be creating this system because its a project for university. Its not going to be published online or anything, just a simple demo in front of suoervisor n examiner. Im gonna simply create a database within the application to hold all the data.Now i need to have user login feature capability so the right messages are displayed to the right users. I wants the messages to be as a "thread". Any idea how this can be done in asp.net? im using visual studio 2008 .net framework 3.5.
Im creating a messaging system which is a bit like the inbox feature of this forum. So far I have built the page with a datalist (as this is the advice i was given). I just want to know how I should create the tables within the database so that the thread of messages is seen by the right people when they login and view messages. Which is basically the 2 people messaging each other. The system is gonna have user sign in functionality as well.
I built a little web application that displays charts. I was thinking that it might be useful for the superuser of the app to do a complete data refresh, however this process takes around 10 minutes to complete. I was thinking perhaps the user could click a button that would start off a new thread to do a data refresh and subsequent clicks would kill the thread and restart the data population process. The user would then be free to browse about the site and view the charts as their data is populated.
Is there a simple method of accomplishing something like this?
EDIT: ViewState does not change when browser is refreshed, so even if you write to viewstate it will not save the data. i am trying to store a Queue in a viewstate (to track postbacks and refreshes to stop a form from resubmitting). The Queue is only saving with a count of 1 (the first item that is added to it) no matter how many items i add.
// New Queue of strings private Queue<string> sTemp; private Queue<string> p_tempQue { set { ViewState["sTemp"] = value; } get { return (Queue<string>)ViewState["sTemp"]; } } //BasePage constructor public BasePage() { //create a Queue of string //sTemp = new Queue<string>(); this.Load += new EventHandler(this.Page_Load); this.Init += new EventHandler(this.Page_Init); } //In the 'page_Init' event we have created a simple hidden field by name 'hdnGuid' which is attached to the page on the first hit itself. protected void Page_Init(object sender, EventArgs e) { //initializing the hidden field //create a hidden field with a ID HiddenField hdnGuid = new HiddenField(); hdnGuid.ID = "hdnGuid"; //if it is the first time the page is loaded, create a new guid and assign it as the hidden field value if (!Page.IsPostBack) hdnGuid.Value = Guid.NewGuid().ToString(); //add the hidden field to the page Page.Form.Controls.Add(hdnGuid); } //In the 'page_Load' event we check if the hidden field value is same as the old value. In case the value is not same that means it's a 'postback' //and if the value is same then its 'refresh'. As per situation we set the 'httpContent.Items["Refresh"]' value. protected void Page_Load(object sender, EventArgs e) { if(p_tempQue != null) sTemp = p_tempQue; else sTemp = new Queue<string>(); //The hdnGuid will be set the first time page is loaded, else the hdnGuid //will be set after each time the form is submitted using javascript. //assign the hidden field currently on the page for manipulation HiddenField h1 = (HiddenField)(Page.Form.FindControl("hdnGuid")); //create an instance of the GuidClass GuidClass currentGuid = new GuidClass(); //set the GuidClass Guid property to the value of the hidden field currentGuid.Guid = h1.Value; //check to see if the Queue of strings contains the string which is the current Guid property of the GuidClass //if the are equal, then the page was refreshed if (sTemp.Contains<string>(currentGuid.Guid)) { //adds item as key/value pair to share data between an System.Web.IHttpModule interface and an System.Web.IHttpHandler interface during an HTTP request. System.Web.HttpContext.Current.Items.Add("IsRefresh", true); } //if they are not requal, the page is not refreshed else { //if the current Guid property in the GuidClass is not null or not an empty string //add the new Guid to the Queue if (!(currentGuid.Guid.Equals(null) || currentGuid.Guid.Equals(""))) sTemp.Enqueue(currentGuid.Guid); System.Web.HttpContext.Current.Items.Add("IsRefresh", false); } p_tempQue = sTemp; }
I have a web application where users can upload the photo. I do have a windows service running which takes the uploaded photo and crops it to different sizes. This runs in a specified interval. Photo will be visible to the user once after it's cropped. So once user uploads the photo and photo cropper has not yet run, they wont be able to see the photo. Due to this behaviour user thinks that there was some error uploading the photo and they will upload it again and again.
where the photocropper runs immediately when the user uploads the photos which is queued.
I'm trying to get a better handle on how threads work in ASP.NET, so I have a test site with a few pages, and I have a test WinForms client that creates 40 roughly concurrent requests to the test site. The requests take about 5-10 seconds to complete--they call a web service on another server. When I run the test client, I can use Fiddler to see that the requests are being made concurrently. However, when I look at Performance Monitor on the web server, with counters "ASP.NET Apps v2.0.xxx/Requests Executing", "ASP.NET/Requests Current", "ASP.NET Requests Queued", these counters never display more than 2.
This is the case regardless of whether the test page I'm requesting is set up with Async=True and using the Begin/End pattern of calling the web service, or if it's set up to make the call synchronously. Judging by what I see in Fiddler, I would think I should be seeing a total of 40 requests in one of those states, but I don't. Why is that? Do these counters not mean what I think they mean?
In the main thread I open a new thread that gets the number of new messages of user (takes about 5 secs) and this second thread should save the number in some place.
In the main thread I should check the "some place" and if the value exists I display it on the page.
Where can I save the value from the second thread to read it from the main one? This value is unique per user so I can't use static field.
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?
