Web Host Uptime Monitoring purpose and tools

posted by Smirnovi4 @ 19:53 PM

February 24, 2010

Using web hosting services normally presumes storing content located on a remote server that is available online 24x7x365, which means that such a hosting server is powered and connected to the Internet constantly. A very important notion in web hosting technology is uptime. Wikipedia defines it in the following way: “Hosting uptime refers to the percentage of time the host is accessible via the internet“, therefore, if a customer is paying for hosting services, it is crucial for him to expect and receive the maximum uptime values. Although hosting companies do apply various monitoring techniques to track server’s state at any given moment of time, no technology is perfect and thus it is important to perform your own independent uptime monitoring, which may come in handy in emergency situations. So how do you measure uptime values correctly? Should you expect a 100% uptime? What web site monitoring tools are available to a regular user? These questions are not as simple as they appear at a first glance. Information in this article will be useful to those interested in understanding and monitoring uptime of an account or server.

Who should pay attention to web host uptime?

To begin with, let’s find out why we should be interested in having maximum uptime. Importance of this parameter greatly depends on the goals assigned to your hosting account or server. Users with personal blogs, forums or regular web pages do not worry as much as people doing e-commerce, managing blog for marketing purposes, providing advertising services with your content, using hosting services as communication system for business, sending customers to affiliate programs, etc., as for the latter type of hosting customers the server downtime impacts their income either directly or indirectly. In case your profit, reputation or status depends on the availability of your content, it is a very good idea to perform uptime tracking.

Nature of server uptime

As it has been stated above, server uptime is its availability on the Internet, but the server is not a solid entity that simply appears on the internet as an object. There are always various services running on a web host. They ensure presence and correct presentation of data on the network. Major services handled by *nix (here *nix goes out for UNIX, Linux and FreeBSD driven servers) servers today are:

Apache server (responsible for http, php, cgi etc.);
MySQL server (responsible for work with MySQL databases);
Mail server (responsible for e-mail services: POP, IMAP, SMTP);
FTP server (responsible for FTP connections and transfers);
SSH server (responsible for SSH jail/full shell connectivity);
DNS server (handles domain name related operations and settings).

To use each of these services, you need to be connected to each one of them. If you are browsing through your website, you are likely using only Apache server (i.e. http). At this point you can already think of this process as the simplest http uptime check (by sending connection requests and receiving results from a server). If you are checking emails with a mail client, such as Mozilla Thunderbird or Microsoft Outlook, you are interacting directly with the mail server. When uploading new content using FTP client, you are only communicating with the FTP server. As you can see, in a variety of cases operations performed by a user at one given point in time include either one or few services simultaneously. Imagine a situation when you can successfully receive mail messages, but at the same time nothing (normally “nothing” is considered to be a certain kind of error, 401 for example) is displayed when you are viewing your web site via browser (i.e. a downtime situation takes place). This often means that Apache server is experiencing problems (as html pages are normally processed by the http service).

When we are considering availability, we should keep in mind that server downtime can be either full or partial. It is normal for a hosting company to guarantee a 99,9% uptime figures, as the underlying value normally assumes percentage of time a web server is not spending in full downtime state. As any other devices, servers can and do get broken for various reasons. In many cases it is very hard to predict when exactly and why a server can fail. What is more important is whether a hosting company is capable of fixing the issue in time and with minimal impact on the customers. We at Sitevalley.com spend a lot of resources on server monitoring and always have a backup plan in case something goes wrong. We use special network monitoring software to constantly track status of our servers. Our network’s multiple redundant backbone connectivity links all of our Datacenters, using multiple high capacity lines. These Datacenters are maximum security, carrier-class facilities with fault tolerant power systems. All of them have state of the art IP architecture aimed at reliable delivery of your content 24x7x365.

Web site monitoring tools

After having defined uptime meaning and importance, let’s take a look at monitoring tools available for hosting users. We immediately can divide these checking utilities into two primary groups:

free;
paid.

The paid solutions mostly include the web based services that perform monitoring of web sites from numerous locations across the Globe. The technology behind such utilities is as follows: a certain number of interconnected servers with installed monitoring software send various requests (http, MySQL and DNS) to monitored locations. Based on the responses they receive, using special algorithms, they make conclusions about the current state of the location (i.e. a web site). Consequently, these results are stored and pictured as graphs with time dependence. Users utilizing such tools can be notified about critical states of their web sites via e-mails, instant messengers, SMS messages and so forth. The testing results posted at labnol.org will be very useful for those looking for a good paid server monitoring solutions. Main advantages of the paid uptime checking solutions are:

consistency of results;
higher accuracy due to numerous locations the testing is conducted from;
high response speed;
variety of notification methods;
service quality;
independence from your own computer and ISP;

The main drawback is price, of course.

Free website monitoring services are normally divided into the following three classes:

standalone server applications (need to be installed on a web server);
free monitoring services analogous to the paid ones;
standalone desktop software.

Free monitoring web based services use the same technology as paid services, but they offer lower response times and lower accuracy of results. The latter is due to the fact that such services normally use less monitoring points (i.e. locations) across the Globe to perform checks. There are exceptions, of course, one of which being a GIGRIB service, offered by the Pingdom Company (a very popular and effective monitoring services provider). GIGRIB uses its own customers as monitoring sources (this statement refers to the PCs of the customers). Such approach provides a very high accuracy due to high number of users.

Standalone server applications require installation on a separate hardware server. This type of solutions is widely used by webhosting companies to perform in house network monitoring. At the same time, standalone desktop applications are the worst and least efficient choices for users. These uptime monitoring techniques are very limited by the local ISP’s service quality. If the ISP servers go down, then your webhost will appear as unavailable for the applications relying on the local network. Such alerts may lead to false evaluation of your host’s service quality. You can find several lists of popular services from all presented categories in the following articles:

Conclusions

Web site uptime monitoring is crucial for those users, whose income directly depends on the availability of their content. Uptime figures themselves are a very complex notion, dependent on various parameters, and when evaluating them, one should always keep in mind diversity of the conditions that influence these values. It is important to understand, that there are various types of uptime guarantees used by hosting companies. These guarantees very often assume the partial uptime figures. Monitoring availability of your own hosting account or server is quite important. Timely detection and reaction to the downtimes may help you save money and reputation. The descriptions and links given in the article will help those seeking proper uptime control utilities find them. This should consequently lead to higher income and ratings of web resources.

Looking for a better and reliable hosting solution? Check our cheap Linux servers and cheap VPS hosting offers.

Tags: Server Downtime, Sitevalley, Uptime, Uptime monitoring tools, uptime tracking, Web based server status monitoring