No, this is NOT the "my page doesn't have any traffic and it has to be reloaded" issue.
We have 4 dynos for an alpha application. The reason we do, is because each page takes over 2 seconds to load. Even little things like rendering a text string (no layouts, erb or anything).
If I watch our logs, for our longer queries, they report response times in the 300-700ms range--which is far shorter than 2 seconds.
The DNS is cached, and the collective time to load given that isn't a slow DNS issue. And, that shouldn't affect subsequent page loads, right?
Any thoughts on how to get to the bottom of this would be appreciated.
Here are two screenshots to show what I mean.
http://dl.dropbox.com/u/7175041/Screenshots/qo.png
http://dl.dropbox.com/u/7175041/Screenshots/qq.png
Thanks!
First thing I'd do is to switch on NewRelic Basic - it's a free performance monitor integrated with Heroku. That'll help you get a bearing on the basics of where the trouble is coming from.
I take it that you don't see similar results locally? If you don't, then skip this step, but if you do, you can also run NewRelic locally and interrogate all of your queries for response times.
I'd stay away from using things like the Benchmark library - that was my first thought in troubleshooting a speed issue, but Benchmark is necessarily going to ignore elements of your app that are outside the pure Ruby layer, and if that's where you're slow then NewRelic catches that anyway.
Finally, if all else fails, a support ticket with Heroku's team has always been extremely helpful to me. Just make sure you check the box that lets them clone your app, it makes things a lot easier for them.
Let us know what you find out - I'm curious to see what the particular gremlin is!
Related
I'm trying to get going with JMeter, and am having trouble finding a really simple tutorial for the first "getting started" the docs seem to be very verbose, covering all kinds of scenarios.
Can anyone point me at something that would take me from having downloaded the app (I can run it, and get a gui) to the point where I can send a single, predefined GET request, at a specific rate.
Just one request, no login, nothing. But I'd like to be able to send it at a selected rate.
This will do two things for me, first, get past that wall of info that I'm finding and give me a starting point from which to experiment. Second, it's actually pretty much all I want to do anyway; I don't want to record results, I just want to hit a server at specific steady state rates, and observe the OS level impact on the server when it stabilizes (number of threads, memory usage, rate of context switching, cpu usage). I'll get to more complex things later, maybe.
I'm sure someone has written something to achieve this, but google keeps finding heavyweight "tomes" that are off-putting to wade through and feel like they're wasting huge amounts of my time :(
(Oh, and I did search here, but only found more complex stuff; hope I didn't get egg on my face with a duplicate!)
TIA,
Toby
I find Blazemeter's JMeter tutorial to be very beginner friendly:
http://community.blazemeter.com/knowledgebase/topics/10018-jmeter-tutorials
http://community.blazemeter.com/knowledgebase/articles/197560-jmeter-video-tutorial-writing-your-first-jmeter-s
(I'm not affiliated with Blazemeter)
The structure of the simplest JMeter Test Plan as per your scenario should be something like:
Thread Group - to set a number of threads and iterations
HTTP Request - to configure endpoint, path, parameters, etc.
Constant Throughput Timer - to set exact desired request execution rate (N requests per second)
Hope this helps.
Gach, as so often is the case, the terminology was obscuring that first level of understanding that allows one to make use of the docs. I found what I needed right there in the regular documentation:
http://jmeter.apache.org/usermanual/build-web-test-plan.html
My website http://theminimall.com is taking more loading time than before
initially i had ny server in US at that time my website speed is around 5 sec.
but now i had transferred my server to Singapore and loading speed is got increased is about 10 sec.
the more waiting time is going in getting result from Store Procedure(sql server database)
but when i execute Store Procedure in Sql Server it is returning result very fast
so i assume that the time taken is not due to the query execution delay but the data transfer time from the sql server to the web server how can i eliminate or reduce the time taken any help or advice will be appreciated
thanks in advance
I took a look at your site on websitetest.com. You can see the test here: http://www.websitetest.com/ui/tests/50c62366bdf73026db00029e.
I can see what you mean about the performance. In Singapore, it's definitely fastest, but even there its pretty slow. Elsewhere around the world it's even worse. There are a few things I would look at.
First pick any sample, such as http://www.websitetest.com/ui/tests/50c62366bdf73026db00029e/samples/50c6253a0fdd7f07060012b6. Now you can get some of this info in the Chrome DevTools, or FireBug, but the advantage here is seeing the measurements from different locations around the world.
Scroll down to the waterfall. All the way on the right side of the Timeline column heading is a drop down. Choose to sort descending. Here we can see the real bottlenecks. The first thing in the view is GetSellerRoller.json. It looks like hardly any time is spent downloading the file. Almost all the time is spent waiting for the server to generate the file. I see the site is using IIS and ASP.net. I would definitely look at taking advantage of some server-side caching to speed this up.
The same is true for the main html, though a bit more time is spent downloading that file. Looks like its taking so long to download because it's a huge file (for html). I would take the inline CSS and JS out of there.
Go back to the natural order for the timeline, then you can try changing the type of file to show. Looks like you have 10 CSS files you are loading, so take a look at concatenating those CSS files and compressing them.
I see your site has to make 220+ connection to download everything. Thats a huge number. Try to eliminate some of those.
Next down the list I see some big jpg files. Most of these again are waiting on the server, but some are taking a while to download. I looked at one of a laptop and was able to convert to a highly compressed png and save 30% on the size and get a file that looked the same. Then I noticed that there are well over 100 images, many of which are really small. One of the big drags on your site is that there are so many connections that need to be managed by the browser. Take a look at implementing CSS Sprites for those small images. You can probably take 30-50 of them down to a single image download.
Final thing I noticed is that you have a lot of JavaScript loading right up near the top of the page. Try moving some of that (where possible) to later in the page and also look into asynchronously loading the js where you can.
I think that's a lot of suggestions for you to try. After you solve those issues, take a look at leveraging a CDN and other caching services to help speed things up for most visitors.
You can find a lot of these recommendations in a bit more detail in Steve Souder's book: High Performance Web Sites. The book is 5 years old and still as relevant today as ever.
I've just taken a look at websitetest.com and that website is completely not right at all, my site is amoung the 97% fastest and using that website is says its 26% from testing 13 locations. Their servers must be over loaded and I recommend you use a more reputatable testing site such as http://www.webpagetest.org which is backed by many big companies.
Looking at your contact details it looks like the focus audience is India? if that is correct you should use hosting where-ever your main audience is, or closest neighbor.
I have been using codeigniter for quite sometimes and i really love it. But for some reason i am not sure why but rendering a view in 1 of my application takes 18-23 whole seconds. Well i really wonder why as such time is to be taken for rendering the output.
I am sure about this as i measured the time from it reaching the Index Page till the data collection / preparation from the system. All took not less then a second. Just this rendering of the view page screwed up - taking 19 / 23 random seconds.
I really want to understand why as so and will like to get a proper through solution to work around on the same.
As for now i am caching the output and storing it and playing around with it but i too know it is not so full proof solution. There must be a way to analyze as where and why the rendering takes so much time on the server. If anyone knows anything about the same, please please do update / share on the same.
Have you tried using XDebug? There are a lot of online resources for how to use it in profiling your PHP apps, such as this one by Eric Hogue.
But if you included some sample code of what is happening in your controller and view then perhaps we could offer some specific guidance in this instance.
Removing a call to $this->carabiner->empty_cache(); speeds up our views quite a bit.
We have website, which is based on Drupal. There is a ~30 modules, which is not huge amount for our VPS. We have no high traffic, so traffic doesn't making Site overload.
On same VPS we have other Sites which are loading properly.
Site: http://jnews.am
Where I can start? How can I check what part of my server/website is causing performance issues? What investigating methods you can suggest?
You need to dig in to find out the bottle-neck. Here is a good article about it. http://www.mindyourcode.com/php/drupal-profiling-performance-analysis-for-optimization-finding-the-performance-bottlenecks-in-your-application-at-core-level/
Good question. Here's some answers:
1) Downlaod the YSlow extension to Firefox, and install it. This will let you test on a number of different items that can suggest why your site may be slow. This doesn't currently look to be your current big problem right now, though.
2) Install the Firebug extension to firefox. The 'Net' tab of firebug tells you how long every document took to download. your core page is taking 5 seconds, and for some reason system.css is taking almost as long, which is unusual in that it's a static file.
3) Check and see if you've got any slow queries, and why. Assuming you're using mysql, this page http://dev.mysql.com/doc/refman/5.0/en/slow-query-log.html tells you how to set up the slow query log, which will collect and report which queries are taking a long time to complete.
Beyond that, some suggestions: You're almost certainly not using some of Drupal's performance options, such as caching, and I would suggest using memcache to speed the site up as well. (See http://drupal.org/project/memcache)
It really looks like you've got a query that's taking too long. It seems to me that the slow query log is what's going to be the most useful tool - it'll tell you where you need to optimize your site. Do note that mysql tends to use the first index on a table that it finds in the WHERE clause instead of the fastest, and as such a query like "WHERE type='story' AND status = 1" is faster than "WHERE status = 1 AND type='story'", because there type index filters the data better than the status one. (And Views tends to put the items in the where clause in the same order that they're in the Filter section.)
Website Page load times on the dev machine are only a rough indicator of performance of course, and there will be many other factors when moving to production, but they're still useful as a yard-stick.
So, I was just wondering what page load times you aim for when you're developing?
I mean page load times on Dev Machine/Server
And, on a page that includes a realistic quantity of DB calls
Please also state the platform/technology you're using.
I know that there could be a big range of performance regarding the actual machines out there, I'm just looking for rough figures.
Thanks
Less than 5 sec.
If it's just on my dev machine I expect it to be basically instant. I'm talking 10s of milliseconds here. Of course, that's just to generate and deliver the HTML.
Do you mean that, or do you mean complete page load/render time (html download/parse/render, images downloading/display, css downloading/parsing/rendering, javascript download/execution, flash download/plugin startup/execution, etc)? The later is really hard to quantify because a good bit of that time will be burnt up on the client machine, in the web browser.
If you're just trying to ballpark decent download + render times with an untaxed server on the local network then I'd shoot for a few seconds... no more than 5-ish (assuming your client machine is decent).
Tricky question.
For a regular web app, you don't want you page load time to exceed 5 seconds.
But let's not forget that:
the 20%-80% rule applies here; if it takes 1 sec to load the HTML code, total rendering/loading time is probably 5-ish seconds (like fiXedd stated).
on a dev server, you're often not dealing with the real deal (traffic, DB load and size - number of entries can make a huge difference)
you want to take into account the way users want your app to behave. 5 seconds load time may be good enough to display preferences, but your basic or killer features should take less.
So in my opinion, here's a simple method to get a rough figures for a simple web app (using for example, Spring/Tapestry):
Sort the pages/actions given you app profile (which pages should be lightning fast?) and give them a rough figure for production environment
Then take into account the browser loading/rendering stuff. Dividing by 5 is a good start, although you can use best practices to reduce that time.
Think about your production environment (DB load, number of entries, traffic...) and take an additional margin.
You've got your target load time on your production server; now it's up to you and your dev server to think about your target load time on your dev platform :-D
One of the most useful benchmarks we use for identifying server-side issues is the "internal" time taken from request-received to response-flushed by the web server itself. This means ignoring network traffic / latency and page render times.
We have some custom components (.net) that measure this time and inject it into the HTTP response header (we set a header called X-Server-Response); we can extract this data using our automated test tools, which means that we can then measure it over time (and between environments).
By measuring this time you get a pretty reliable view into the raw application performance - and if you have slow pages that take a long time to render, but the HTTP response header says it finished its work in 50ms, then you know you have network / browser issues.
Once you push your application into production, you (should) have things to like caching, static files sub-domains, js/css minification etc. - all of which can offer huge performance gains (esp. caching), but can also mask underlying application issues (like pages that make hundreds of db calls.)
All of which to say, the values we use for this time is sub 1sec.
In terms of what we offer to clients around performance, we usually use 2-3s for read-only pages, and up to 5s for transactional pages (registration, checkout, upload etc.)