I Don’t Know What To Say Except That I Have Enjoyed Reading – Olino

 slashdot effect At the peak 03 dot 25PM / 09 dot 25AM, the OliNo site received 2320 visitors per hour.

At 12 dot 00PM / 06 dot 00AM.

The overall number of visitors kept growing any hour. So this translates back to around 39 visitors any minute. You see, the bottleneck can be CPU, IO or network. Perform your load test, find the bottlenecks, try to solve them by adjusting the set up, do your performance tests again. With that said, most of us are aware that there are a few options which can be tuned like the Apache webserver, the MySQL database or even the Linux kernel.a single way to find the real bottleneck your performance tests on an identical ‘nonproduction’ set up. During these tests the load on the server can be controlled and the server can be monitored closely. For instance, we are clearly guessing now, as you can see. Repeat this process until you are satisfied with the performance. Of course, this process is iterative. To be able to handle a bigger load on the webserver one could start using multiple instances.

 slashdot effect Until the time comes when Amazon will offer a load balancing service in their EC2 environment, people are forced to use a softwarebased load balancing solution.

This effectively means we need at least 4 small EC2 instances.

Effectively quadrupling the current cost price of using a single EC2 instance. Remember, the web traffic gonna be load balanced over the two web servers. Then the next step could’ve been running two small instances with the apache webserver with wordpress and a third instance with MySQL. Then again, with some having their own Javascript files, now this would mean we need to do loads of customizing, as we use a bunch of WordPress plugins. I am wondering if that’s worth the effort with the new WordPress 8 already announced where plenty of there problems will be solved automatically. Now this calculates back to 590 KB/s of continuous traffic. With 914 KB, the webpage is quite large. Throughout the peak we got 2320 visitors per hour. So this generates 914 KB x 2320 = 2 GB per hour of data traffic. So this should not be the bottleneck. Nonetheless, often lots of readers will hit the link to read the story, when Slashdot links a site.

 slashdot effect Besides, the site is said to be Slashdotted, when this happens.

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

Slashdot website serves around 3 million pages on weekdays, and slightly less on weekends. It’s a well 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. Lots of us are aware that there is a great document about Apache Performance Tuning on the website of Apache. A well-known fact that is. So that’s a first step we can take. You should take it into account. Amidst the first tips is to check the MaxClients option. Actually, our Apache webserver isn’t tuned for performance.

 slashdot effect Current setting is Setting this value should result in error in the log.

An explanation gonna be that at similar time, the Europeans take a lunch break and the eastcoast of the USA awakens.

Result is the perfect storm completely overloading the web server. It’s an interesting fact that the impact of the Slashdot effect is clearly visible in the response time of the web server. While in the course of the peak the response time went skyhigh, as already seen in the graph above. Now this happened at exactly 12 dot 00PM. I will visit this blog very often. Now let me tell you something. Nice blog. I recently came across your blog and was reading along. I don’t know what to say except that I have enjoyed reading.

I thought I should leave my first comment.

We use Google Javascripts for showing Ads with Google Adsense and monitoring traffic using Google Analytics.

Another question isSo the question is this. Does it make sense, to take these scripts and combine them with your Javascripts to improve performance? Remember, 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? What about Javascript from Google? It seems we need to reduce the general amount of MaxClients from 150 to 50 for our Apache configuration. Normally, the tip of Apache is to divide the available percentage of memory for Apache by the percentage of memory used in Top by a single Apache thread. Nonetheless, our Apache thread uses between the 16 20MB per thread. Known 1024 MB reserved for Apache / 20MB per Apache thread ~ 50 MaxClients. Value ain’t ain’t shown. Anyways, setting this value since the first group of visitors came to the website. At 08 dot 35AM the server load was already increased to 27, a clear indication that the server is already overloaded. Whenever using the Linux p command, is mostly about 3 during normal traffic, in the course of the day a lot more visitors came from different parts of the world. Plenty of visitors came still from the USA. In the evening we have received 27169 visitors from 134 countries/territories. So this instance has 7 memory GB, 1 EC2 Compute Unit, 160 GB of instance storage, 32bit platform. Instance is running in the ‘useast1b’ datacenter of Amazon. Just think for a moment. One EC2 Compute Unit provides the equivalent CPU capacity of a 02″ GHz 2007 Opteron or 2007 Xeon processor. On p of that, the OliNo website is using a small instance type. With an interval of 5 minutes the response time of the website is measured from the different locations.

They have probe servers which are located in the USA, Canada, UK, Sweden and France.

a notification is send when the server is unavailable.

I know that the response time of the website is monitored by a global monitoring network service of Pingdom. That said, this process is iterative. Perform your load test, find the bottlenecks, try to solve them by adjusting the set up, do your performance tests again. Of course, during these tests the load on the server can be controlled and the server can be monitored closely. The main way to find the real bottleneck your favorite performance tests on an identical non production ‘set up’. Eventually, So there’re a couple of options which can be tuned like the Apache webserver, the MySQL database or even the Linux kernel.

Repeat this process until you are satisfied with the performance.

We are clearly guessing now, as you can see.

And therefore the bottleneck can be CPU, IO or network. So this can take up valuable time it’s just a case of writing the information because, even though Apache keeps the log files open. Notice that 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. There’s some more info about this stuff here. Another option we can use it so disable access logging.

With all that said… We can save few processor cycles by disabling it. Normally, error logging will still be enabled. Notice, writing log information is a time consuming process. 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. Now regarding the aforementioned fact… It must 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.

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

The second tip to use a Content Distribution Network is something Amazon can offer with CloudFront.

Content is delivered with better possible performance, requests for your objects are automatically routed to the nearest edge location. Normally this still young Renewable Energy website gets around 100 visitors per day. At the moment of the post, Europe was just waking up, the US west coast 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. Make sure you write some comments about it below. Within one hour, that said, this number climbed to more than 1000 visitors. It’s a well 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, after the peak. Have you heard about something like that before? This translates back to around 39 visitors each minute.

The tal amount of visitors kept growing every hour. At 12 dot 00PM / 06 dot 00AM. Looking at the details reveals that user processes is only taking 30 CPU usage and the processor is still 16 dot 4 idle. Server load snapshot taken at 08 dot 35AM is a clear indicator the server is overloaded. That’s a cool article and I have posted a link to my twitter account. I will also refer my customers to your AWS experience. Known you can take a glance at my very own ol CloudBerry Explorer that helps to manage S3 and CloudFront. A well-known fact that is. I know it’s a freeware. Our organisation will contribute to reach this goal.

Leave a Comment

Facebook
Facebook
Twitter
Pinterest
Pinterest
LinkedIn