As the title implies, the first "cold" POST to our MVC3 app in the Azure cloud is very slow. Once it "spins up", the normal requests are blazing fast. The first spin-up after a brief period of rest takes a few seconds. Subsequent requests can be measured in milliseconds.
How can we keep this thing awake?
This is probably due to the appplication pool unloading after a period on inactivity. The next request has to take the overhead of starting it up again.
To confirm this, you need to turn on the performance counters and look at the numbers of app domain loads and unloads.
Either way, this blog post explains how to fix it.
Related
I have a backend IIS server that hosts an ASMX web service. During the past months, this web service has been performing very poorly: requests that usually took around 20ms are now taking around 250ms. After investigating the matter in New Relic, I see that the majority of the time (over 90% of the request processing time - well over 200ms) is being spent on this call:
System.Web.HttpApplication+MaterializeHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
In all of my other web services, this call takes no more than 1ms.
I have no idea what is this call and why it is performing so poorly. I tried website recycles and IIS resets, but that didn't help. I also tried to google it for hours, but to no avail.
I should also mention that sometimes, for a few brief hours, this problem disappears and the above call is being executed in less than 1ms, as expected.
Any kind of help will be greatly appreciated.
I got website that running on IIS7 that response very slow during weekend night time, after restarting the application pool the website would response fast for certain of time. As time goes (maybe few hours) the website response become slow again.
I open the resource monitor at task manager, and look for the process for the website, the Average CPU is like 6-8, what makes me curious is the Receive B/s go up to 0.8-1MB while the Sent B/s only have 200B, I don't know if that is relevant.
So I was hoping to get an insight of what is the problem here.
Your question is a bit vague. For starters, are we talking a web app, connected to a database? If so, what type of database? There could be any number of causes for this.
But from the sounds of it, I would first start with any database queries you have running. I had a similar issue to yours with a web app, which turned out to be the result of an inefficient SQL Stored Procedure. The site would slow down and grind almost to a halt, but would spring back to life after the app pool was restarted. Rewriting the main Sproc solved the problem.
I need some information from you.I have used session.TimeOut=540 in application.Is that effects on my Application performance after some time.When number of users increases its getting very slow. response time nearly more that 2 minutes for a button click also.This is hosted in server in Application pool .I don't know about Application pool much.If Session Timeout is the problem i will remove it.Please suggest me the way to for more users.
Job Numbers,CustomerID,Tasks will come from one database.when the user click start Button then the data saved in another Database.I need this need to be faster for more Users
I think that you have some page(s) that make some work that takes time, or for some reason or a bug is keep open for more time than the usual.
This page is keep lock the session and hold the rest page from response because the session holds all the pages.
Now, together with the increase of the timeout this page is lock everything and here is you response time near to 2 minutes.
The solution is to locate the page that have the long running problem and fix it or make it faster by optimize the process, or if this page must keep the long time running, then disable the session for that one.
relative:
Web app blocked while processing another web app on sharing same session
What perfmon counters are useful for identifying ASP.NET bottlenecks?
Replacing ASP.Net's session entirely
Trying to make Web Method Asynchronous
Does ASP.NET Web Forms prevent a double click submission?
About server
Now from the other hand, if your server suffer from hardware, or bad setup then here is one other answer with points that you need to check to make it faster.
Find out where the time is spent
add the StopWatch in the method which you said "more that 2 minutes for a button click". you can find which statment spent the most time.
If it is a query on DB that cost time. Check your sql statement.
are you using "SELECT Count(*)" instead of "SELECT Count(Id)"? the * is always slower. also, don't try "SELECT * FROM...."
Use cache.
there are many ways to do cache. both in ASPX pages and your biz layer.
the OutputCache is the most easy way.
and also, cache the page (for example a blog post) on the first time when a user visit it.
Did you use memory paging?
be careful when doing paging on gridview or other list. If you just call DataSource=xxx and DataBind(), even with PagedDataSource, this is likely a memory paging. It cost a lot of performance. Please use stored procedures to do paging.
Check your server environment
where did you deploy the website? many ISP will limit brandwide and IIS connection count and also CPU time to your account.
if you have RD access to your server. you can watch CPU and memory usage to see if they are high when many user comes to your site. If the site is slow and neither CPU nor memory useage is high, it may be a network brandwide problem.
Here are some simple steps to narrow down the issue -
1) Get HTTPWatch (theres a free Basic version) available and check whats really taking time from an end user perspective. Look at number of requests, number of resources downloaded, and the payload. If there is nothing to worry move on to next
2) If its not client, then its usually the processing time on the server. Jump on to DB first - since this is quite easier to eliminate quickly. Look at how many DB calls are made (run profiler in staging or dev) and see if there are any long running queries, missing indexes or statistics, and note the IO. If all is well, move on
3) Check your app code. You could get on with VS.NET in build profiler or professional tools such as Ants. If code is fine then its your network or external calls that you make, check your network bandwidth. If you still cannot narrow down, check your environment/hardware
The best way to get to it is to apply load - You could use simple tools such as ab.exe (that comes as part of Apache Web server) to have concurrent hits on your server and run the App, DB profilers in the background to get to the issue.
Hope this helps!
We have a complex app that serves AJAX JSON streams (using ADO to grab the data) using brief ASP servlets. Any given session can fire up from 10-20 of these requests simultaneously. We encountered a significant performance problem way earlier than we expected as load built. (Server is a dual-XEON, RAID 5, 4gb, etc). Sleuthing around in perfmon we noticed that the 'Requests Executing' figure is perpetually stuck at 1. Never gets any higher. Research indicates that numbers of 20-50 are not uncommon. Requests Queued will hover around 10-20 and Wait Time climbs as well.
We have fiddled with ASPProcessorThreadMax set to 40 from default of 25 with no effect. It seems to be only able to work a single request at a time, which, needless to say, won't work. I can't find anything that describes this particular problem. Anny help is greatly appreciated.
ASP Session object is constrained to a Single Threaded Apartment (STA). As a result requests to ASP scripts for the same session can only be processed sequentially.
An additional reason why you might only ever see 1 executing ASP script even across multiple sessions is where debugging has be enabled for ASP. This causes the ASP processing to ignore ASPProcessorThreadMax and pretend it were set to 1.
To eliminate the problem ensure debugging is not enabled and turn off "Enable Session State". If you are using the Session object in your code you will need to find an alternative, like DB backed state.
However, how many active concurrent sessions are you expecting in the live production? Perhaps the overall user experience will not truely be impacted by the serialisation of requests per session.
I have a website set up with in IIS 7 with HTTPS, and every time a user access it for the first time the load time is about 15 sec.
THIS IS NOT the compile/warm up "problem" described for instance her: Slow first page load on asp.net site
I know about that "problem" and I also have that, but that is of course expected and not the issue here.
Since it's not when the application loads first time since recycle/start. If I open another browser and access it after doing it first in another browser then it takes the same amount of time. So it seems every time a session is started, that's when the delay happens. All following requests from the same user/browser is as quick as expected.
This is for an admin interface site I have and I use asp.net membership. Although the delay happens even before the user have logged in. So I'm not sure if that is the culprit.
I am a bit unsure where to look for killing the delay. I am running session state in process. With cookies.
Any ideas?
You need to get a little more information. Enable trace and track how long each step takes. You could also use Wireshark and have a look at the traffic between the client/server. If there is a big gap in traffic you can see something is hanging at the servers end. If you see constant traffic perhaps you have to much going on with your landing page. Other simple things to do would be to enable dynamic caching/compression on the server to speed things up.
Warm it up...
http://learn.iis.net/page.aspx/688/using-the-iis-application-warm-up-module/