While our website is not yet complete graphically and design wise, most of the backend operations are near completion.
However, after optimising the mysql database we are still receiving a significant initial receiving period when tested on pingdom.com:
http://tools.pingdom.com/fpt/#!/IuoBna86v/http://foscam-uk.com
According to Pingdom:
The yellow part is the time it takes to resolve the hostname and similar (before the connection is initiated to the web server), the green part is connecting to the web server, and the blue part is the time it takes to retrieve the content from the webserver.
Upon asking our managed VPS support team we got the response : 'Have you tried optimizing your script? I believe that the high wait time on there indicates actual website loading time (meaning for your script to load); not actual connection to the website/server.'
Now, pingdom shows the js/css loading relatively quickly, the mysql database side of things doesn't seem to be slowing anything down either - does anyone have any suggestions of what this could be or might be causing it?
Thank you very much for your time and help.
89 requests are too many.
Reduce number of image request by creating sprites.This is pretty important from what is shown in pingdom.
Keep Alive should be set to On and Keep alive time should be a bit higher(15 seconds or so).
Use of compiler plus merge and minify js/css is recommended.
Change the hosting provider. 8 second loading is very very slow. It means that it actually is around 15-17 seconds for a user that doesn't have cached parts of your site (first time visitor). My site www.bebepunk.ro loads according to pingdom in 2.5 seconds and users still complain about the slowness of the site. Check also with http://www.webpagetest.org for both values.
Related
Across all browsers/devices, I find random different pages, at random times, are very slow to load/don't load. The browser is stuck on 'Waiting for website.com'. I will wait 20 seconds and nothing will happen until I manually refresh the page. As I realise this is very vague, can you suggest a) most likely issues to look for first or b) some diagnostic tools that I could use to try and de-bug the issue as a starting point, so that my hosts/developers can solve the issue. Here are some results of recent speed tests.
One thing to also add is that, it seems it more often gets stuck on particular pages. Namely the pages where users take practice tests. After each time the user clicks 'Next', their selected answer is inserted into the database. My speculation is that potentially it's an issue with the DB itself, or the process which inserts into the database. It's when clicking 'Next', that the whole website sometimes just dies as described above.
Results from Google Speed Test
Waterfall image
A wait time of 20secs at random times and random pages could possibly be due to stop-the-world garbage collection. So GC logs are probably a good starting point.
A thread sampler such as Djigger a colleague of mine wrote might probably also help you figuring out what the machine is doing during the 20 seconds.
If that doesn't help I suggest to use a Profiler or better an APM tool to monitor whats going on on your system. Those tools give a you a broader insight of the internals.
You need to run a few page speed tests and look at the waterfall images.
It is very common on shared servers for the server to be too busy to get to your request. 20 seconds would indicate a serious issue with the server.
Another common reason is the page has a link to a third party resource and that resource is too often unavailable.
In your case the culprit is website.com and I assume that is your site.
Use something like webpagetest.org to run the tests.
In the waterfall image below
Dark Green is DNS lookup time.
Orange is the time for Browser to connect to server.
Green is the wait time for server to put image in output buffer.
Blue is the time for the server to transmit to the Browser.
The problem with the sample waterfall page is the index page took 4 seconds to be generated or retrieved. Most likely this is a Word Press site with plugins.
I suspect yours may be 20 seconds. But due to the randomness, is is also a good possibility it is a page resource that is stalled.
If it is the index page, then you likely have a poor ISP and or one of the other users of the server is hogging the CPU.
Keep running the tests until you see the problem occur.
It will be very obvious where the problem is located.
You can post the waterfall image and send me a message if you have any questions.
Waterfall from webpagetest.org
I am using a shared hosting plan at Bluehost to host a golf tournament live scoring mobile web app. I am caching everything I can on Cloudflare, and spent quite some time on overall optimization of the initial download & rendering times. There might be more I could do, but without question my single biggest issue is the initial call to my website: www.spanishpointscup.org. Sometimes this seems to be related to DNS lookup and other times related to Waiting(TTFB).
Below are 2 screen shot images of the network calls that show variations in accessing my index.html. Sometimes this initial file load can be even longer. Very rarely are any of the other files downloaded creating a long delay time, so my only focus now is the initial file load. I think that even if I had server side rendering, I would still have this issue.
Does anyone have specific recommendations that they are confident will help me? Switch to VPS or other host? Thank you.
This is typical when you use a shared server.
The DNS has nothing to do with the issue. DNS has to do with the request not the response. It is the Browser that must resolve the the domain name to an ip address.
The delay you are seeing is due to the server being busy and your page is sitting in a queue waiting behind other processes. Possibly you have a CPU grabbing neighbor on your shared server. Or Bluehost has some performance issues.
You will likely notice some image files take an excessively long time to transmit. Which image is slow will appear to be random with each fresh (not in cache) page load.
UPDATE
After further review I noticed the "wait" times are excessive. Wait time is in green on your waterfall. Notice how the transmit time (blue) is short. This is the time it takes the server to retrieve the page from the disk and put it into the transmit buffer. 300-400 millisecond is excessive.
Find a new service provider.
We are eventually going to use CDN but currently all files are loaded from the same domain as the main site.
I am perplexed to see close to 15 secs of blocked time. The site loads reasonably fast at my end but at the client's environment it takes 30 sec for the first time load.
All optimization for loading has been implemented (gzip, expiry...etc) and the site ranks 95 in gtmetrix.
Any suggestions as to why this might be happening at the clients computer ?
First of all note that Firebug's 'Blocking' time actually the time required to establish a connection with the server. In the Firefox DevTools this is more obvious:
And the connecting time may be influenced by several factors. In your case it looks like the images are blocked by the styles.css file, which takes extremely long to load regarding its size. I assume, this is caused by some proxy server or web application firewall or something else that may slow down the receiving of that file.
We're running 3 different Drupal (Pressflow to be specific) sites on the same server. The 2nd and 3rd sites were cloned from the first one and load just fine. The first one, though, is taking a few seconds to connect and start sending data back from the server. Same box, same config (as far as we know), same modules, and generally the same theme. Here's what Pingdom shows...
Fast site:
http://i.stack.imgur.com/YZilC.png
Slow site:
http://i.stack.imgur.com/6Um1M.png
Edit: Those are from Pingdom, the yellow indicating "The web browser is waiting for data from the server"
The configs are the same, performance options same, server configs, as far as we can tell are the same. The delay occurs before any page elements are visible so it's not an on-page object problem or a page speed problem.
Could this be a config issue with the server? Where should we be investigating?
Thanks in advance!
I would try increasing the size of your MySQL cache. It's possible the fast sites have their particular queries cached and the slow site has a query that doesn't quite fit the cache, so the MySQL query results need to be regenerated each time.
Just a guess!
I have a site that is moving incredibly slowly right now. Both Safari's inspector and Firebug are reporting that most of the load time is due to latency. The actual download is happening in less than a second. There's a lot of database activity in play (though the metrics on that indicate that it's pretty healthy), but what else can cause really high latency? Is it a purely network thing or are there changes I can make to the app to improve the latency numbers?
I'm using YSlow to help identify performance improvements, but on the whole, I don't see it reporting anything that seems crazy unreasonable. Opportunities for improvement, certainly, but nothing that seems like it would cause the huge load times I'm seeing.
Thanks.
UPDATE
Some background and metrics, in case it's useful. This is a CakePHP application and I'm using my UsersController::login action as the benchmark. For the sake of identifying how much of a factor the application code plays in this, I've printed a stacktrace immediately upon entering UsersController::beforeFilter(). Here's output:
UsersController::beforeFilter() - APP/controllers/users_controller.php, line 13
Controller::startupProcess() - CORE/cake/libs/controller/controller.php, line 522
Dispatcher::_invoke() - CORE/cake/dispatcher.php, line 187
Dispatcher::dispatch() - CORE/cake/dispatcher.php, line 171
[main] - APP/webroot/index.php, line 83
Load times, as shown by Safari's inspector range from 11.2 seconds to 52.2 seconds. This would seem to point me away from the application code and maybe something with my host, but maybe I'm completely misinterpreting this or oversimplifying it?
If you cannot identify directly a slow moving component of your application, there are a number of other steps along the way that can certainly slow your site down. Whenever I'm experiencing unusually long polling, I typically start by looking at the local DNS and then onto my hosted DNS. Sometimes a cache refresh (on their part, not yours) can cause a lot of polling until their database has caught up.
Else, they might actually have a service outage and your requests are being made to their secondary or backup server. If everything seems fine in terms of domain resolution, your hosting provider might be experiencing a service outage that can take a number of different shapes like serving static content from their backups or over-allocating shared resources until everything is running as it should. You can experience a ton of what they call throttling on shared cloud architectures when they have a box go down. On the plus side, you don't have a total outage in this circumstance.
One time, and this was just in a shared grid configuration, I had a processor go to hell. The bizarre part of it was that static content was still serving from a backup, but it was still polling against our database (which was on a different server) and causing our account to throttle because of over allocation on the backup. Wasn't our fault, but the host started sending nasty emails about our excessive long-polls. Moral of the story is, if it's not your application, and it's out of the blue, somewhere along the line I'll bet you'll find some hardware failure or misconfiguration.
Also now that I think of it, if you are syndicating some outside content (be it server or browser side) it might not be in your chain of responsibility altogether. If you are serving ads for example from a subscriber service, they might be having a high-load period or outage. These are just the steps that I would take to narrow down the culprit.
Probably this will be not the solution for you, but when I has doggy slow safari (and FF too) I simply changed the DNS servers to opendns (208.67.222.222, 208.67.220.220) and all my problems are resolved.