Hi
I've been working on a medium sized MVC project. It works fine on the localhost at a good speed rate. In each page, there's a lot of server-side data retrieved, I use a lot of jquery to minimize the traffic to the server, but even then, the webpage loads very slowly. There are many events on which I retrieve json results, to get a specific number from the database and make calculations, this data takes a long time to be retrieved on the webpage, although on the localhost it is immediately shown. Also, when I submit pages, it takes awfully a lot of time to submit. I've published my project to GoDaddy's server and also my database is there. What could be the problem that is making the project that slow? How can I minimize it? And why is it only when the website is online and not on the localhost too?
As such, issue can be anywhere and only certain way to know is instrumenting the code. I will suggest that you add simple logging traces with date-time stamp in your server code (note that logging should be configurable, any logging framework (including System.Diagnostic.Trace) should support it) and check where the time is spent. For example, database trips can be expensive etc. If you don't find the culprit on server side code i.e. sever is serving the request in reasonable time then you have to look at the performance over network. Tools such as Fiddler (or Firefox) should help you here - sometimes issuing too many requests from browser is also problematic because browser may make only n concurrent requests or even server may have been configured to accept only n requests from particular client - this could result in serialization of request increasing total response time. These scenarios are difficult to catch on localhost because network latency is almost zero there. You may also use tool such as YSlow for related performance improvement suggestions. But please do your investigation first, find the bottlenecks and then ask for solutions to specific problems.
Run it in chrome. Turn on the developer tools. Expand the Console. watch for errors. Also from there you can monitor those network calls to see which is slow.
if MVC uses entity framework (based on LINQ), it will sure be slow
because LINQ is slow compared to the old ADO.NET
Related
We have an ASP.NET MVC application hosted in an azure app-service. After running the profiler to help diagnose possible slow requests, we were surprised to see this:
An unusually high % of slow requests in the CLRThreadPoolQueue. We've now run multiple profile sessions each come back having between 40-80% in the CLRThreadPoolQueue (something we'd never seen before in previous profiles). CPU each time was below 40%, and after checking our metrics we aren't getting sudden spikes in requests.
The majority of the requests listed as slow are super simple api calls. We've added response caching and made them async. The only thing they do is hit a database looking for a single record result. We've checked the metrics on the database and the query avg run time is around 50ms or less. Looking at application insights for these requests confirms this, and shows that the database query doesn't take place until the very end of the request time line (I assume this is the request sitting in the queue).
Recently we started including SignalR into a portion of our application. Its not fully in use but it is in the code base. We since switched to using Azure SignalR Service and saw no changes. The addition of SignalR is the only "major" change/addition we've made since encountering this issue.
I understand we can scale up and/or increase the minWorkerThreads. However, this feels like I'm just treating the symptom not the cause.
Things we've tried:
Finding the most frequent requests and making them async (they weren't before)
Response caching to frequent requests
Using Azure SignalR service rather than hosting it on the same web
Running memory dumps and contacting azure support (they
found nothing).
Scaling up to an S3
Profiling with and without thread report
-- None of these steps have resolved our issue --
How can we determine what requests and/or code is causing requests to pile up in the CLRThreadPoolQueue?
We encountered a similar problem, I guess internally SignalR must be using up a lot of threads or some other contended resource.
We did three things that helped a lot:
Call ThreadPool.SetMinThreads(400, 1) on app startup to make sure that the threadpool has enough threads to handle all the incoming requests from the start
Create a second App Service with the same code deployed to it. In the javascript, set the SignalR URL to point to that second instance. That way, all the SignalR requests go to one app service, and all the app's HTTP requests go to the other. Obviously this requires a SignalR backplane to be set up, but assuming your app service has more than 1 instance you'll have had to do this anyway
Review the code for any synchronous code paths (eg. making a non-async call to the database or to an API) and convert them to async code paths
So I've been running into some speed issues with my site which has been online for a few weeks now. It's an MVC3 site using MySQL on discountasp.net.
I cleaned up the structure of the site and got it working pretty fast on my local machine, around 800-1100ms to load with no caching. The strange thing is when I try and visit the live site I get times of around 15-16 seconds, sometimes freezing up as long as 30 seconds. I switched off the viewstate in web.config and now the local loads in 1.3 seconds (yes, oddly a little longer) and the live site is down to 8-9 seconds most of the time, but that's still pretty poor.
Without making this problem to specific to my case (since there can be a million reasons sites go slow), I am curious if there are any reasons why the load times between the local Visual Studio sever or IIS Express would run so fast while the live site would run so slow. Wouldn't anything code wise or dependency wise effect both equally? I just can't think of a reason that would affect the live site but not the local.
Any thoughts?
Further thoughts: I have the site setup as a sub-folder which I'm using IIS URL Rewriting to map to a subdomain. I've not heard of this causing issues before, but could this be a problem?
Further Further Updates: So I uploaded a simple page that does nothing but query all the records in the largest table I have with no caching. On my local machine it's averages around 110ms (which still seems slow...), and on the live site it's usually over double the time. If I'm hitting the database several times to load the page, it makes sense that this would heavily affect the page load time. I'm still not sure if the issue is with LINQ or MySQL or MVC in general (maybe even discountasp.net).
I had a similar problem once and the culprit was the initialization of the user session. Turns out a lot of objects were being read/write to the session state on each request, but for some reason this wasn't affecting my local machine (I probably had InProc mode enabled locally).
So try adding an attribute to some of your controllers and see if that speeds things up:
[SessionState(SessionStateBehaviour.Disabled)]
public class MyController : Controller
{
On another note, I ran some tests, and surprisingly, it was faster to read some of those objects from the DB on each request than to read them once, then put them in the session state. That kinda makes sense, since session state mode in production was SqlServer, and serialization/deserialization was apparently slower than just assigning values to properties from a DataReader. Plus, changing that had the nice side-effect of avoiding deserialization errors when deploying a new version of the assembly...
By the way, even 992ms is too much, IMHO. Can you use output caching to shave that off a bit?
So as I mentioned above, I had caching turned off for development, but only on my local machine. What I didn't realise was there was a problem WITH the caching which was turned on for the LIVE server, which I never turned off because I thought it was helping fix the slow speeds! It all makes sense now :)
Fixing my cache issue (IQueryable<> at the top of a dataset that was supposed to cache the entire table.. >_>) my speeds have increased 10 fold.
Thanks to everyone who assisted!
I have an asp mvc app hosted at www.jacquelinewhite.co.uk. When I use firebug (net tab or page speed) I'm seeing response times of 200 milliseconds for an action that isn't cached and about 30 for a cached action result. However, my reports from pingdom.com are showing an average of between 3 and 7 seconds for a response.
The application is set not to recycle and sits at a consistent memory level. I can't see any CPU spikes and basically everything looks fine, except the response times are a lot slower than I'd hope for.
I'm inclined to think it's not a problem with pingdom and the google webmaster tools shows the sites as slower than 54% of other sites.
Where else might I look at to identify the sites slowness?
Well, as luck would have it, the Stackoverflow team has just released an MVC Profiler (which was originally developed to profile this family of sites). The profiler is available from code.google.com/p/mvc-mini-profiler and also as a NuGet package. You should be able to use it to profile your site and perhaps spot any bottle-necks.
Another useful profiling-type tool is called Glimpse:
"At its core Glimpse allows you to
debug your web site or web service
right in the browser. Glimpse allows
you to "Glimpse" into what's going on
in your web server. In other words
what Firebug is to debugging your
client side code, Glimpse is to
debugging your server within the
client."
I need to display logfiles in real time to user webpage using ruby/rails. Users should be able to see logfile steaming without refreshing the page.
Logfiles may not always be in the same machine which runs rails.
Is it possible in ruby/rails ?.
You could do this with automatically refreshing page, using AJAX when JavaScript is available (this avoids page flicker and extra bandwidth usage caused by a page reload).
The other approach (actually incrementally updating page) consists of two separate issues: (1) reading the file as it grows, and (2) sending the answer without closing the connection. I have seen some solutions doing this (not in Rails, though), but unfortunately they tend not to be very reliable (browsers and other parts of the system will timeout) and the users get confused when the page loading never finishes.
Ruby and Rails can read files, but the issue is going to be accessing from different machines. Are the logfiles on the same network?
What you're asking for is not necessarily Rails-specific. It's more a question of technology, IMO.
Because the classic web model is client/server and pushing data asynchronously is not standard, you'll need to figure out how to do it either by:
1) faking it by polling on the client.
2) use a different technology. For Rails, you may want to look into something like comet or websockets.
I have a website that is hanging every 5 or 10 requests. When it works, it works fast, but if you leave the browser sit for a couple minutes and then click a link, it just hangs without responding. The user has to push refresh a few times in the browser and then it runs fast again.
I'm running .NET 3.5, ASP.NET MVC 1.0 on IIS 7.0 (Windows Server 2008). The web app connects to a SQLServer 2005 DB that is running locally on the same instance. The DB has about 300 Megs of RAM and the rest is free for web requests I presume.
It's hosted on GoGrid's cloud servers, and this instance has 1GB of RAM and 1 Core. I realize that's not much, but currently I'm the only one using the site, and I still receive these hangs.
I know it's a difficult thing to troubleshoot, but I was hoping that someone could point me in the right direction as to possible IIS configuration problems, or what the "rough" average hardware requirements would be using these technologies per 1000 users, etc. Maybe for a webserver the minimum I should have is 2 cores so that if it's busy you still get a response. Or maybe the slashdot people are right and I'm an idiot for using Windows period, lol. In my experience though, it's usually MY algorithm/configuration error and not the underlying technology's fault.
Any insights are appreciated.
What diagnistics are available to you? Can you tell what happens when the user first hits the button? Does your application see that request, and then take ages to process it, or is there a delay and then your app gets going and works as quickly as ever? Or does that first request just get lost completely?
My guess is that there's some kind of paging going on, I beleive that Windows tends to have a habit of putting non-recently used apps out of the way and then paging them back in. Is that happening to your app, or the DB, or both?
As an experiment - what happens if you have a sneekly little "howAreYou" page in your app. Does the tiniest possible amount of work, such as getting a use count from the db and displaying it. Have a little monitor client hit that page every minute or so. Measure Performance over time. Spikes? Consistency? Does the very presence of activity maintain your applicaition's presence and prevent paging?
Another idea: do you rely on any caching? Do you have any kind of aging on that cache?
Your application pool may be shutting down because of inactivity. There is an Idle Time-out setting per pool, in minutes (it's under the pool's Advanced Settings - Process Model). It will take some time for the application to start again once it shuts down.
Of course, it might just be the virtualization like others suggested, but this is worth a shot.
Is the site getting significant traffic? If so I'd look for poorly-optimized queries or queries that are being looped.
Your configuration sounds fine assuming your overall traffic is relatively low.
To many data base connections without being release?
Connecting some service/component that is causing timeout?
Bad resource release?
Network traffic?
Looping queries or in code logic?