Lies, Damn Lies and 99.9% Uptime
“There are three kinds of lies: lies, damn lies, and statistics.”
-Benjamin Disraeli, popularized by Mark Twain
Lies, Damn Lies and 99.9% Uptime
Statistics don’t lie outright. They just don’t tell the whole truth.
Suppose your hosting provider claims 99.9% uptime during the past month. This means all the accumulated downtime during the whole month was no more than 40 minutes. Sounds great, right?
The numbers don’t answer one important question: when did the downtime occur? What if you were down 40 minutes during your peak usage time on the busiest day of the week? Suddenly 99.9% of uptime doesn’t sound so great. That’s the whole truth often missing in uptime reports.
The All Important Monitoring Interval
Convinced you can do better than 99.9%, you search for another hosting provider. You finally settle on one that offers an additional “nine” or 99.99% uptime per month. No more than 4 minutes of downtime.
Before you get too excited, let’s see where that extra nine comes from by examining the concept of monitoring interval. The monitoring interval is how often your hosted server is checked to make sure everything is working A-OK. Think of it as the lines on a ruler. It’s going to be pretty hard to measure down to one eighth of an inch if your ruler only has one inch lines on it.
Suppose your application is monitored every 15 minutes. Now say your server is rebooted. If the monitor runs while the server is down, your server will show as down for 15 minutes, even though it only takes 3 minutes to reboot. If the monitor misses the reboot window, it won’t show as being down at all.
A provider that offers 99.99% must have a small enough monitoring interval that it can measure down to the nearest .01%. How small is that exactly? Let’s break it down using the shortest month:
28 days x 24 hours/day x 60 minutes/hour x .0001 = 4.03 minutes
A service provider must provide a monitoring interval of no more than 4 minutes to provide a 99.99% uptime guarantee.
Finally, what of 99.999%, the so-called “five nines” of uptime? Well, we would have to monitor every .4 minutes or every 24 seconds. With the reporting period increased to a year instead of a month, it’s possible to have accuracy up to five nines with a 5-minute monitoring interval. Trouble is, who wants to wait a whole year for a report?
The best reporting will include a combination of daily, weekly, monthly and yearly statistics for comparison.
What Do You Mean, Down?
Now that you understand what a monitoring interval is, this next one should be easy: what is the meaning of “down”? If your service provider is providing uptime, how do they decide when something is down? Are they simply doing a “ping” of the server? Or are they testing the application itself?
If “up” to them means your server is running, even though your application is really “down”, your uptime statistics take on a whole new meaning — or lack of meaning.
Also, who is the one actually doing the monitoring? Ideally, you’d like to have a third party monitoring service. That way you know your monitoring numbers are independently verified.
Availability From a Business Perspective
There is a better way. Instead of settling for the one-size-fits-all approach of “nines of uptime”, set your own availability goals. The key is to examine availability from a business perspective:
- What are my business-critical periods?
- How much downtime is acceptable during off hours?
- What kind of monitoring interval is needed?
- How do we know if the application is down?
- Who is actually doing the monitoring?
Always make a distinction between business hours and after hours. You should have different availability requirements for each period, even if your application is used 24×7. Next, create your goal using words and whole numbers, not percentages. For example:
- Zero downtime during business-critical periods.
- No more than 2 unscheduled downtime incidents per month of no more than 5 minutes per incident during after hours periods.
- No more than 1 scheduled maintenance period per month of no more than 30 minutes during after hours periods.
- Monitoring interval of 5 minutes.
- Monitor key aspects of the application, not the server.
- Independent third-party monitoring from multiple locations.
After defining exactly what your availability goals are, you can now strive to achieve it. The difference now is that your goal is 100% achievable. That’s a statistic you can count on. Glen Kendell is a network architect and owner of Release to Production. He publishes a monthly newsletter called In-Production: Achieving True High Availability.
All About Dedicated Web Hosting Providers
Unless overtly listed otherwise, most web hosting packages you’ll come across in your search are what are called shared hosting providers. What this means is that the server or servers that host your website are simultaneously hosting numerous other websites also. This gives you a discounted rate on web hosting services in exchange for tolerating certain technical constraints, like bandwidth, disk space, upload and download speeds, security and privacy, traffic, and probably the most notable restriction — total control.
If you want total control not only over the administration of your website but also over the very hardware and software used to run it, then you should be evaluating not shared hosting providers, but dedicated hosting providers. If your business is large enough or growing fast enough that it requires its own internet connection and server, you may need a dedicated web host.
What’s the downside to going with dedicated hosting providers? In a word: responsibility. In most areas of life, with total control comes total responsibility, and it’s no different with hosting providers. With a dedicated server, the onus is on you to buy, install, and maintain the actual equipment — the server itself — mounted in the dedicated hosting providers’ data center.
Fortunately, you still get the benefit of their presumably top-notch, around-the-clock security over the physical premises, but you remain fully responsible for the security of your cyber-premises. Likewise, dedicated hosting providers will ensure that the systems in the building are all provided with redundant uninterruptible and backup power and environmental controls, but it’s you who must keep your machines and cables maintained and functioning in this idyll environment.
How do you identify whether it’s time to switch from a shared host to a dedicated host? There are 3 main indicators to stay alert for:
Speed
If the traffic streaming through your shared server is slowing down your customers’ pace as they browse your site (or your employees, if an in-house site), it may simply be time to look for more unencumbered shared hosting. But if you’ve tried several shared hosting providers with the same results, then it may be time to remind yourself how impatient the average web surfer is. While you’re jumping from shared host to shared host trying to save a buck, your customers are jumping ship. Your ability to respond promptly and effectively to customer transactions and inquiries cannot be overemphasized either.
Reliability
The limits to your control are nowhere more apparent than in the areas of reliability and security. It’s not simply that problems can arise: problems do arise. It’s the nature of the biz. And if you don’t have unlimited access to your own operating system, software and database apps, etc., there’s not much you can do when one arises.
Customizability
If your company is growing fast, you’re going to be changing many aspects of your web presence along with it. You may regularly need to tweak your disk space and bandwidth and experiment with using different applications to better serve your changing needs. On a shared host, upgrading in such a way usually involves leaping from one “package” or “plan” to another. These packages are generally preset and may or may not serve your immediate needs. They may be riddled with programs you don’t yet need, for example, yet lack in the one singular program you do. Or the next leap up from your current plan has way more disk space and bandwidth than you need at the moment. With a dedicated server, you can make changes incrementally, step forward, step back, heck, step sideways if you need to — and when you need to.
In large part, it’s the size and growth rate of your business that will dictate whether you need a shared or dedicated host. Affordability and personal time commitment are nice secondary considerations, but if your business is booming, you would do it a great injustice to try and save on a few bucks and few extra hours per week of your time in exchange for slower and poorer quality of service for your customers.
By the same token, however, if your business is small enough to function quite smoothly on any of the shared hosting providers out there, don’t squander your precious capital on a dedicated server just so you can have total control. Because sometimes total control isn’t all it’s cracked up to be.
Hosting-Review.com is the premier resource on web hosting providers. Visit http://www.hosting-review.com for comprehensive reviews and rankings of over 50 web hosts, as well as informative hosting articles.
Web Site Hosting: From Domain Registration to Going Online – Part 3
After your account has been opened with your web host and you’ve set the DNS for your website (see Parts 1 and 2 for more information) you can start to upload your content. The most common way this is done is through FTP (File Transfer Protocol) software, but there are a few other options as well.
The FTP protocol lets you transfer data files from one computer to another. Your web hosting company will give you the information you need to connect to your site with FTP.
You normally would use software like WS_FTP or FileZilla to connect. Your FTP address will usually be ftp.yourdomain.com.
Your web host will also tell you where your files should be uploaded to on the server. There is usually a folder in the root directory of your website called public_html, www or something similar. This is where you need to store all your website files to make them accessible to the public on the internet.
You might have to adjust some settings in your FTP software to make the files upload properly. eg. If you’re running a firewall on your computer (or a hardware firewall) you may need to set the transfer method to “passive”. And if you’re using a proxy server, you’ll have to adjust those settings as well.
Files can be transferred with FTP in either ASCII or binary mode. If you use the wrong mode to transfer, you could end up with errors. Your FTP software might automatically determine which method to use by looking at the contents of the files you’re transferring. It’s possible that you might have to specify the mode manually, however.
Files that should be sent as ASCII include HTML (and variations like HTM, SHTML, etc.), TXT, ASP, JS, PHP, etc. Essentially, any file that you would open with a text editor should be transferred as ASCII.
Binary mode is used to transfer files such as graphics, compiled programs and media files.
With your FTP software, connect to your web server. Open the folder where you’re going to upload the files and then find the files on your computer that you’re going to send. You can transfer individual files or entire directories using FTP.
Most of the pages on your website can be named anything you want, but the home page or main page in any subdirectories should be named index.htm (or .html, .php, etc.) The name “index” tells the web server that this is the file that should be displayed by default.
So if someone goes to www.mydomain.com, what they’re actually going to see is www.mydomain.com/index.html, the web server just displays that file automatically so they don’t need to enter the “index.html” part.
If you don’t put an index file in each directory on your site, people might be able to browse the directory and see “behind the scenes” on your website. This can be a security issue in some cases, so it’s always a good idea to put an index page in each directory, even if it’s just a blank page.
What Other Ways Can You Upload Your Website?
FTP isn’t the only way to upload your web pages. Many web page creation programs have transferring built-in. Probably the most common example of this is Microsoft Frontpage. If your web host supports Frontpage, you can upload your site from within Frontpage itself and you don’t need to worry about how or where to transfer things. Frontpage takes care of everything for you.
Some web hosts also offer online site-builders. These builders work within your web browser and let you layout your web pages. Once your pages are finished, they automatically get saved to the appropriate location on your server.
These online site-builders are usually available through the control panel in your hosting account.
John Lenaghan writes about how to choose ecommerce web hosting, business hosting and other website hosting topics on the Hosting Report website. Find out more at http://www.hostingreport.org
How To Determine How Much Space And Bandwidth You Need For Your Website
How much storage space and bandwidth will you need for your website? This is a question that you will need to answer before deciding on your web site hosting.
You’ll need to look at the content that you’ll be hosting on your site. Is it just plain text? Images? Audio and video files?
Plain text takes the least amount of space. Images take considerably more and audio and video files will need the most space. This applies to both the storage and the bandwidth.
Many web hosts offer what seems like a huge amount of storage space, assuming that you’ll never use it. If everyone hosting websites on their server were to use the maximum space allowed, the servers would likely not be able to handle it.
You’ll see a range of storage and bandwidth being offered. One host might be offering 1 gigabyte of storage while another could offer 500 megabytes at the same price. The quality of service is a key factor in choosing a web host, so don’t just look for the one with the biggest offer.
The rule of thumb in the hosting industry is that 2MB of storage is enough to host 10 web pages and 4 or 5 images. Using this as a guideline, you can determine how much space you’ll need to host your site.
You can calculate your bandwidth requirements in a similar way. Make sure you understand the difference between bandwidth and data transfer, however.
In non-technical terms, bandwidth is the diameter of a water pipe and data transfer is the amount of water that flows through it. If you’re likely to have a lot of data being transferred, you should look for high bandwidth plans.
If you choose a plan with high data transfer but low bandwidth, your site can slow to a crawl when it gets too many visitors. The amount of information you’re allowed to transfer is high enough, but the pipe it’s flowing through doesn’t allow enough to get through at once to keep up with all the requests.
The best way to manage your bandwidth and space is to keep your site as simple as possible. Don’t use large images – optimize them for viewing on the web which will decrease their size considerably.
If you’re not sure how to determine your needs, the better web hosting companies will be able to help you figure out which of their plans will best suit your website.
John Lenaghan writes about small business web hosting and other website hosting topics on the Hosting Report website. Find out more at http://www.hostingreport.org.
All about Linux/Unix-based hosting
What is Linux/Unix-based hosting?
It means hosting that is provided on Linux/Unix operating systems platforms. There isn’t much difference between these two types of operating systems because Linux/Unix is an improved version of Linux/Unix operating system. When just applying for web hosting companies for web hosting that is based on Linux operating system it doesn’t matter which one you are using on your computer as it is commensurable with any operating system.
Usability
Some years ago Linux operating system used to be available only for professionals and if you were not an experienced user you had no future with this OS. In the last couple of years the situation has changed. Providers have done their best to make users’ web sites administrating more comfortable and easier. In case you’re just a beginner you’ll find friendly control panels that include Web- interface. And if you are an experienced user you can control your site by means of shell.
Reliability
Experts claim that Unix-based platform is one of the most reliable ones but it will mainly depend on maintenance stuff professionalism. Thus quality and stability of Linux-based web hosting won’t depend on some sudden system bugs and the operating system consistency itself secures your web site operating dependability.
Functionality
In this area Linux differs the most from other popular platforms. It can handle a lot of processes that happen at the same time. This gives you a possibility to get more from the server.
What Scripting Languages Are Available For Unix?
Unix supports a wide variety of application languages, more than any other operating system. The most common applications of such kind include C, C++, Shell, Perl, Tcl, Python, Java and PHP.
What Databases Does Unix Support?
Databases available for Unix are mSQL and mySQL. The one you choose would depend on your own needs and your Host Provider’s offers. This is important for you to review when choosing a hosting company.
Cost
Linux operating system was developed by Linus Torvalds as an alternative to other operating systems and is being improved by many specialists all around the world. Most of its versions are free of charge. This circumstance makes Linux-based hosting much cheaper than any other. As for Linux versions they are sometimes called Linux Distributions. The most popular Distributions are RedHat and Mandrake. Which are easy to install have a lot of different utilities and suitable for any web hosting type.
Why choose Linux/Unix-based hosting?
So, as it was mentioned before using this platform is cheaper and more convenient than others. All existent scripts, like PHP, function best when using the Linux-based web hosting. Linux/Unix based web hosting upgrading possibilities increase when using Shell and Telnet access. The Linux/Unix-based platform is probably the most stable and reliable.
More hosting articles you can also find here http://www.cheap-web-hosting-directory.com , http://www.web-site-hosting-reviews.com and http://www.web-hosting-review.net .