OliNo

Olino – setting this value Basically the benefit of working in a group is if one gets caught, others in the mob still walk away with a lot of stolen merchandise. Other times, they exchange the goods for gift cards, consequently sell those gift cards for cash. Whenever emerging trends in retail, says Ernie Deyle, a retail industry consultant and co author of the Checkpoint Systems’ Retail Holiday Season Global Forecast, the rise of flashmob robbers over the past seven years is the most significant. While referring to how quickly surveillance videos of the heists are shared across social media, these events have become more in vogue and popular via ‘viral spread,’ he says. I am sure that the second tip to use a Content Distribution Network is something Amazon can offer with CloudFront.

CSS file and theme images are loaded on the CDN this will offload a bunch of HTTP request from the main web server, when the javascript file.

 slashdot effect

Content is delivered with top-notch possible performance, requests for your objects are automatically routed to the nearest edge location.

Amazon CloudFront delivers your content using a global network of edge locations.

Some digging on the internet shows that using Amazon Cloudfront will double the bandwidth costs for your website. It should also result in a faster loading website for the visitor as the content to load is located more closely to the physical location of the visitor. So site is said to be Slashdotted, when this happens. Often loads of readers will hit the link to read the story, when Slashdot links a site. Essentially, the Slashdot website serves around 3 million pages on weekdays, and slightly less on weekends. While causing the site to buckle under the strain, when all those Slashdot readers start crashing the party, it can saturate a smaller website completely.

 slashdot effect

So this can easily throw thousands of hits at the site in minutes.

This gives a clear indication that the web site needs loads of tweaking to get a better performance.

Amidst the first things we did is to analyse the website with the very nice Firefox plugin YSlow. Preferably you must have only one Javascript and one CSS file. So it’s also suggested to use minified version for the Javascript files. Actually, the webpage has 14 external Javascript files, 6 external CSS StyleSheets and 24 CSS background images. Remember, the improvements suggestions are sorted on most impact on top. Of course the tip given we have to combine as much Javascript files and Stylesheets into both single files. It’s a well-known fact that the tip to minimize HTTP requests, is the first we must tackle. Yes, that’s right! The value ain’t isn’t shown. Of course, 1024 MB reserved for Apache / 20MB per Apache thread ~ 50 MaxClients. Setting this value By the way, the tip of Apache is to divide the available quantity of memory for Apache by the quantity of memory used in Top by a single Apache thread.

Our Apache thread uses between the 1620MB per thread.

It seems we need to reduce the general number of MaxClients from 150 to 50 for our Apache configuration. So, the server load snapshot taken at 08 dot 35AM is a clear indicator the server is overloaded. For example, looking at the details reveals that user processes is only taking 30 CPU usage and the processor is still 16 dot 4percentage idle. One EC2 Compute Unit provides the equivalent CPU capacity of a 0 2 GHz 2007 Opteron or 2007 Xeon processor. Keep reading. The OliNo website is using a small instance type. Actually the instance is running in the useast1b datacenter of Amazon. Therefore this instance has 7 memory GB, 1 EC2 Compute Unit, 160 GB of instance storage, 32bit platform. So here is the question. Does it make sense, to take these scripts and combine them with your personal Javascripts to improve performance?

 slashdot effect

Is it allowed and does it work?

Is it faster to keep them on the they are already in the browsers cache of the visitor, Google servers?

We use Google Javascripts for showing Ads with Google Adsense and monitoring traffic using Google Analytics. What about Javascript from Google? With all that said… I changed some MySQL settings. Prior the slashdot effect, the mysql database settings where optimized with the MySQL Performance Tuning Primer script. See also the results of a recent performance analysis and the current MySQL settings. ‘autoscaling’ could start up more instances to handle the increased load, when mostly there’s a huge peak in visitors. Remember, this makes sense, as long as with Amazon EC2, you only pay for running instances per hour. Therefore this could be very effective for surviving the slashdot effect.

 slashdot effect

Now look, the loadbalancer will balance the load over the running web server instances.

‘auto scaling’ will stop a lot of running instances, when the load writes again as long as the visitors are gone.

Gether with the announcement of Amazon for their loadbalancer solution they announced a feature called autoscaling. On p of this, this makes it possible to start / stop instances depending on the load of a number of instances using a voting mechanism.

Now let me tell you something. Slashdot has become so popular that there’s a name, Slashdot effect, for what happens to some smaller websites when a post on the site links to them. Actually, I recently came across your blog and been reading along. I don’t know what to say except that I have enjoyed reading. Needless to say, nice blog. Besides, I thought I will leave my first comment. Write visit this blog very often. With some having their own Javascript files, now this would mean we need to do plenty of customizing, as we use a bunch of WordPress plugins.

I am wondering if it is worth the effort with the new WordPress 8 already announced where lots of there problems will be solved automatically.

Normally this still young Renewable Energy website gets around 100 visitors per day.

Within one hour, so this number climbed to more than 1000 visitors. At the moment of the post, Europe was just waking up, the US westcoast was just intending to bed and the US eastcoast was still sleeping. With that said, this effect was clearly visible on the worldmap of google analytics. Certainly, I guess this will only work for re visiting users. For instance, this shan’t prevent an overload of the server since the Slashdot effect.

So remaining tips like adding Expires header and configure ETags are both cache related.

To be able to handle a bigger load on the webserver one could start using multiple instances.

Web traffic may be load balanced over the two web servers. Therefore this effectively means we need at least 4 small EC2 instances. Effectively quadrupling the current cost price of using a single EC2 instance. Until the time comes when Amazon will offer a load balancing service in their EC2 environment, people are forced to use a software based load balancing solution. So, the next step gonna be running two small instances with the apache webserver with wordpress and a third instance with MySQL. Whenever rating items on a scale of 1 5″ and assigning an assessment similar to insightful, funny, interesting, redundant, offtopic or troll, other members act as moderators.

Site members submit summaries of news items with links to the sources. Slashdot was founded by Rob Malda and Jeff Bates in The site was originally a discussion forum about Linux and related software but has broadened in scope to include any technology related subject as well as other pics like politics, science and culture. It’s a first step we can take. Lots of us are aware that there is a decent document about Apache Performance Tuning on the website of Apache. Among the first tips is to check the MaxClients option. Our Apache ‘web server’ ain’t tuned for performance. Current setting is Setting this value must result in error in the log. While in line with in accordance with Jeff Hemos Bates, the site was renamed as a play on how terrible I know it’s to say domain names out loud. Slashdot started out as Chips and Dips.

In this case.

We simply comment out the log lines in the configuration file, with the intention to do this.

In our case we do not use the access log. We can save few processor cycles by disabling it. Another option we can use it so disable access logging. Of course, error logging will still be enabled. Therefore this can take up valuable time it’s just a case of writing the information since, even though Apache keeps the log files open. Considering the above said. Writing log information is a time consuming process. I’m sure it sounds familiar. I will also refer my customers to your AWS experience. And so it’s a freeware. Just think for a moment. You can check my very own ol CloudBerry Explorer that helps to manage S3 and CloudFront.

So it is a cool article and I have posted a link to my twitter account.

Our organisation will contribute to reach this goal.

Undoubtedly it’s a combination of two Catalan words.Oli and No. Let start a civilization which provides for its energy using renewable energy. Gether they mean Oil No! We found an appropriate name for our organisation, OliNo, that is a word joke for No Oil! With all that said… Night we have received 27169 visitors from 134 countries/territories.a bunch of visitors came still from the USA. Throughout the day way more visitors came from different parts of the world. So this load balancing set up is similar how Slashdot has set up their hardware.

It is clearly a proven ‘setup’.

The loadbalancer will balance the load over the running webserver instances.

All the web server instances connect with a single MySQL database so lots of us are aware that there is a single state of the website. Now this calculates back to 590 KB/s of continuous traffic. The general number of visitors kept growing any hour. Now this translates back to around 39 visitors every minute. Throughout the peak we got 2320 visitors per hour. With that said, this generates 914 KB x 2320 = 2 GB per hour of data traffic. Also, at the peak 03 dot 25PM / 09 dot 25AM, the OliNo site received 2320 visitors per hour. The amount of visitors per hour went slowly down with a few hundred visitors less every hour until it stabilised at 11 dot 00PM / 05 dot 00PM, right after the peak. That said, this should not be the bottleneck. I’m sure you heard about this. At 12 dot 00PM / 06 dot 00AM. Explanation could have been that at identical time, the Europeans take a lunch break and the east coast of the USA awakens.

Now this happened at exactly 12 dot 00PM.

The impact of the Slashdot effect is clearly visible in the response time of the web server.

Whenever in the course of the peak the response time went sky high, as already seen in the graph above. Result is the perfect storm completely overloading the web server. Perform your load test, find the bottlenecks, try to solve them by adjusting the ‘setup’, do your performance tests again. And therefore the bottleneck can be CPU, IO or network. Loads of information can be found easily by going online. Repeat this process until you are satisfied with the performance. With that said, this process is iterative. There’re a couple of options which can be tuned like the Apache webserver, the MySQL database or even the Linux kernel. One way to find the real bottleneck your favourite performance tests on an identical non production setup. Certainly, during these tests the load on the server can be controlled and the server can be monitored closely. Now regarding the aforementioned fact… We are clearly guessing now, as you can see. You should take it into account. They have probe servers which are located in the USA, Canada, UK, Sweden and France.

With an interval of 5 minutes the response time of the website is measured from the different locations.

a notification is send when the server is unavailable.

Response time of the website is monitored by a global monitoring network service of Pingdom. On p of that, at 08 dot 35AM the server load was already increased to 27, a clear indication that the server is already overloaded. Did you hear of something like that before? There was an immediate impact on the server load, since the first group of visitors came to the website. While using the Linux p command, is all about 3 during normal traffic, identical page multiple times. Some info can be found by going online. We use the WP Super Cache plugin.

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