My SaaS ASP.Net MVC web app startup time is about 20 to 30 seconds. The typical usage pattern is tied to business hours. So, when the first user in the morning browses to the home page, the page takes about 20 to 30 seconds to load. Thereafter, performance on subsequent page loads is not a problem.
It's running on cloud-hosted infrastructure...Win2008 R2, quad core Xeon with 6GB RAM.
Any pointers as to what I can do to improve this startup time?
The problem might be that your application is being shutdown during idle periods. Try setting up a service to periodically make a request to your application and keep it alive.
Related
There's a similar question about app harbor on StackOverflow, but the user didn't try to use new relic to overcome the problem.
I deployed my ASP.NET MVC project on App Harbor. It's very easy to configure and you can even set automatic deployments from Git. However, as my website is still mainly used only by me, I was getting very long cold starts (over 15 secs). To avoid it, I installed New Relic. The idea was to simultaneously to monitor the application but also to create periodic pings that, according to "a lot of people", would drastically reduce the loading time.
It's not working. I have New Relic correctly pinging my application every minute, but I still get very long cold starts. For instance, 5 min ago, I've got a cold start of 16 seconds. 1 minute after, I got the page loaded in less than a second.
I know I could have used Pingdom or StillAlive to achieve the same result:
How do I improve app performance on AppHarbor?
I wouldn't like to do it because I like New Relic and I don't want to have a lot of add-on's on app harbor as they will slow down my website. Do you have any idea what might be causing it?
I'm not familiar with AppHarbor's setup. But if it's using IIS, the pinging is just keeping the application pool from reaching the idle timeout. But there the default IIS setting for the application pool to be recycled every 29 hours no matter the number of requests. And it's normally in the best interest to let it recycle once in a while, so working around it may not be in your best interest.
Your best bet is to reduce the number of things happening on application start. Precompiling your views is a good place to start. And heck, Stack Exchange/Stack Overflow precompiles views to avoid the application start up cost.
I've got Heroku deployment with my Rails 4 app and it's proving to be extremely slow. I'm not sure if my location has a factor as I'm based in Australia
I've got NewRelic addon and below is the problem that I'm seeing.
Category Segment % Time Avg calls Avg Time (ms)
View layouts/users Template 98.4 1.0 16,800
Based on this breakdown, I see that layout users is the problem for the performance (which is nearly 16.8 seconds!).
Is there a good way to profile this to find out exactly what functions are causing this problem and what are the best way to fix those?
Also another important thing to note is that when I go to map report it shows End User of 19.5 seconds which takes up a lot of time.
When an app on Heroku has only one web dyno and that dyno doesn't receive any traffic in 1 hour, the dyno goes to sleep.
When someone accesses the app, the dyno manager will automatically wake up the web dyno to run the web process type. This causing delay for this first request.
Are you noticing similar behaviour?
I am running Ubuntu (64Bit) with Apache 2.2.17, Passenger 3.0.11, Ruby 1.9.3 and Rails 3.2.6
When accessing the web page (index.html) on my webpage the request takes ages to complete, somewhere around 30 second in extreme cases.
The server has plenty of memory available (top shows more than 4GB free), the Apache processes (there are 10 of them) each show 0% CPU in top and the load is also almost 0 and there are hardly any DB accesses as I cache most of the things with memcached.
The log files of Apache as well as Rails do not show any errors, on the contrary the render times shown in the RubyOnRails log file show excellent values (<100 ms).
So where to go from here?
Is the first request slow or all requests slow? Passengers shutdown after a given time interval. So intermittenly requests (requests with sufficient time span in between) will allow passengers to shutdown (only to be restarted at next request.
Passenger does the autoshutdown BY DESIGN. This is so because on a shared environment, there might be other user's apps. If your app is idle for a while, then the resources can be transferred to other people's app.
If you are on a tight budget and you have multiple apps hosted on the same server, then passenger is a great solution.
If you have only ONE app in your server which you control, then please reconfigure Passengers to NOT shutdown (if that indeed is your problem).
You can do "passenger-status" to see how many passengers are currently running and available for taking requests.
The configuration to ensure that Passengers stay up is PassengerMinInstances and PassengerPoolIdleTime.
Are you accessing it through a 'fake domain name' (added to your /etc/hosts file)?
If so, do
service avahi-daemon stop
At least that's what worked for me on ubuntu 10.10 :)
For some reason a DNS lookup is made on each and every request you do to the server, and when the domain doesn't exists, it times out ...
The performance issue has been keeping me busy for all these days. I believe I have nailed it down to Apache configuration: KeepAliveTimeout, it was set to a very high value (90), can't think why it was set that high, must have been a typo.
My understanding of KeepAliveTimeout is that the Apache process gets locked to the client for 90 seconds, even if the client isn't issuing any further requests, hence when traffic picks up (which it did on that day when performance was significantly reduced, page visits more than tripled) all Apache processes are busy waiting for the KeepAliveTimeout, while blocking all new requests coming in. This would also explain why the system was not showing much load at all, it was just sitting there waiting. I reduced the value down to 10, if traffic picks up I'll probably drop it to 5.
While website loading speed testing I found that website is sometimes loading very quickly and some times it takes lot of time to start loading. When I checked it in detail, I found on some requests wait time was just in few hundred milliseconds, while on some other request which was slow it was actually taking 5 to 30 seconds in wait time.
What may be the cause of this kind of deviation from few milliseconds to 30 or more seconds. And how to improve it.
The site is build upon ASP.net MVC3 and Microsoft SQL Server database.
What patterns are there i.e. are the same URLs always slow, and other URLs always fast, or does it just appear to be random?
Look at what else is running on the server, is it a dedicated server or a VPS?
Look at the DB performance i.e. is it consistent, which are the queries that are taking the longest time, most CPU, most IO etc.
How busy is the site, do the slowdowns match when the app-pool is being recycled or started up?
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?