Web Site Monitoring Service

By Staff
           
You can have the best web site in the world and have the highest ranking on the top search engines, but all that won’t mean anything if your web host’s servers are not fully operational 24/7.

Nothing is infallible in this world and that goes for web servers as well. With tons of computer viruses being released all the time, hardware failures and software glitches all can have an impact on whether or not your web host’s servers stay up and running.

In addition, web servers are vulnerable to hackers, connectivity issues and all sorts of things that can shut them down in a heartbeat. You need to realize this vulnerability and be prepared with a backup plan for your business in the event that the servers go down. In the past year, 41% of Web servers have had substantial down time. That is a fairly large percent when you look at the big picture.

There are many companies on the web that have sprung up that offer monitoring services. These types of services monitor email servers, web sites and also server operational status and performance. Server, email, and web site monitoring are critical to your success. In today's competitive technology driven world, your servers and infrastructure components are business tools, and as such are vital to your company. A server that fails to deliver in a timely manner can easily drive customers away from your site. In addition, vulnerability scanning is a must for every server, e-commerce system, website, and network infrastructure component.

So just how does this monitoring service work? Let’s take a look. Monitoring services monitor email servers (SMTP), web sites and servers (FTP) in general as I said above. They basically monitor the flow, in and out, of email to make sure that the servers are getting and receiving email. It monitors web sites and servers to make sure that they are operating properly and performing at the appropriate level.

These monitoring services will periodically connect to your site or host’s server and check the operational status and performance of the server. If they cannot connect to the server, you will be contacted after they have experienced several failed attempts at connecting to the server. By the same token, once they have successfully connected, you will be notified of their findings in regards to how the server if performing.

Website monitoring is much the same concept as using a Network Management System. The main difference is that a web site monitoring system performs server checks from a customer perspective, on the outside of your firewall using the Internet. In contrast, Network Management Systems are typically located in-house.

The main advantage of website monitoring is that your servers are tested from the "outside looking in". Your customers simply won’t know or care if your website is down because your ISP changed something on his routers, your IT department “improved” security or a system administrator installed new software on your web server.

All the customer knows is that your server is down and he'll possibly just move on to your competitor. In many cases, these types of problems can't even be identified by an in-house system.

The disadvantage is that if website monitoring is your only source of network management, and security is tight on your systems, you might not be able to monitor everything that needs to be monitored.

The good part of monitoring services is that they require no capital investment on your part. You also don’t need to install or maintain software, have any special technical experience or training.  What it does offer you is this, web-based reports, monitors and measures from the end-user perspective, is scalable to meet the needs of any size business, and offers numerous monitoring plans. It is easy to setup an with immediate monitoring of your server. In addition, email-monitoring services perform tests by actually send and receiving e-mail traffic.

What criterion does these monitoring services to determine if a server is operational use?  Let’s take a look.

Determining Operational Status with PING

Most of these monitoring services test the operational soundness of web site servers by using what is called “ping.” Ping is one of the most helpful network debugging tools available. Many say it gets its name from the sound made by sonar on a submarine when it is searching for objects beneath the ocean. When an object is found, the sonar sends back intermittent pinging sounds or pings.  

Testing the soundness of web servers using ping is based on this same premise. Some monitoring services simply use ping to see if a server answers and record the response times during the process. It is used to determine if a server is operational and more important if it is reachable externally.

With ping, a short burst of data also known as a “single packet” is sent to the server. In return the network listens for a single packet reply similar to an echo. The monitoring service learns a great deal about the targeted server from the ping response or lack there of.

The main feature of ping is this echo function. Imaging standing atop the Grand Canyon and shouting out loud, when you stop shouting, what do you hear? Well, it’s your own voice echoing back at you! Ping works in this same manner on the net and is usually a better bet than almost any other network software.

There are many versions of ping however the version of ping that is available for PC’s does not have all the features of let’s say the version that is available for UNIX.

 What ping can do

 ·         The monitoring service sends out a ping. Ping then places a unique sequence number on each single packet that it transmits, and reports, which sequence numbers, are received back. The monitoring service can then determine if packets have been dropped, duplicated, or reordered.

·         Because Ping checksums each single packet it exchanges, the monitoring service can detect some forms of damaged packets.

·         In addition, Ping places a time stamp in each single packet it sends.  This is echoed back and can easily be used to compute how long each packet exchange took to return.

·         Ping reports other important pieces of data such as if a router finds the target host unreachable.

What Ping cannot do

·         Ping cannot always determine why certain packets do not respond back. This is due to several reasons such as the Ethernet, which does not provide link-layer acknowledgments. In addition many routers may silently discard undeliverable packets or be confused as to whether or not the packet has been transmitted successfully.

·         Ping also will not give a reason why packets are dropped, damaged or delayed. It will not tell you just exactly where the process broke down either.

·         Ping will not give you a detailed step-by-step report of what happened during the entire process.

The fact is that there is no software out there anywhere that is reliable enough give this kind of detailed information.

Determining Operational Status by Scripting

When monitoring services set up their server testing devices they sometimes write a script based on specific criteria they want to use to test the operational functionality of a web server with. Many use remote agents (executable files) scattered all over the globe to perform their device checking functions. Their scripting engines also have the ability to generate scripts on the fly based when setting up their test devices.

 Monitoring services that use a scripting engine to create scripts for testing web servers also have the ability to create customized scripts to your specific needs. They could create scripts that not only access the home page, but walk through several pages, supplying form variables along the way; exercising CGI scripts and database connections to check the functionality quality. They can also write scripts that check your e-mail server by sending a test script via SMTP to determine if it arrives by contacting your POP3 interface.

Let’s take a look at what a simple script would look like. Let’s say we wanted to check the functionality of Yahoo.com. Once the monitoring service defines the requirements of the script, the script is written and tested. First, the script checks to make sure that the domain name, www.yahoo.com, can be tied to an IP address. Next, the script checks connectivity to the port that the HTTP server is listening on. Finally, the script initiates an HTTP protocol connection and gets the home page. If any one of these operations fails, the script generates an error.

The scripting capabilities of remote agents allow them to test the capability of virtually any Internet connected device. Custom scripts can travel over web sites and FTP sites, interact with mail servers, and report unusual conditions without taking down the site. In addition the language used in scripting is designed to be easily updateable with new Internet based protocols which allows new features to be added in a timely manner.

Determining Operational Status by Other Means

Some monitoring services use more complex techniques for testing the operational functionality of web sites.  Many employ such techniques as checking web page code, database connectivity, keyword verification, and email round robins.

The most important thing that counts is how a monitoring firm determines operational status. For example, a ping test may verify the server has power, but doesn’t necessarily guarantee a web site or server is operational. Most monitoring services however provide detailed statistics that can be especially helpful in determining operational functionality.

Some monitoring services require that executables be installed on your server. While this practice is not wide spread, it does exist. Most Internet monitoring services can query your site or server service without the need of agents (executable files) or the associated complexity and maintenance required by installing additional software. If your web site’s server is behind a firewall, a firewall rule will need to be established. Most monitoring services will provide originating IP information upon request.

Most monitoring firms email a contact list in the event of an issue. There are four important points to consider: (1) your e-mail availability; (2) the number of people that can be contacted; (3) testing your email devices; and (4) additional costs. If you carry an email enabled cellular phone, pager, PDA, or other device 24/7 you are in great shape. However, if you check e-mail a few times per day, having your server monitored at 2 minutes intervals makes little sense if the monitoring service uses email notification.

Many offer the ability to contact multiple persons. It makes sense to compile a list in the order in which you want people contacted in the event that an issue arises. Make sure that they are people who have the expertise to deal with the issue. They may include your Webmaster, LAN administrator, yourself, or others depending on your staff size, work schedules, or hosting arrangement.

In addition, most monitoring firms have the ability to send "test" messages to your list. This feature is provided to ensure everyone on your contact list is correctly receiving notification messages. Some firms have "additional" charges for pager messages if you exceed a specific number of notifications per month.

Monitoring costs are based on monitoring intervals. In other words, how often they check the site or server. Most monitoring services offer packages ranging from 2 to 60 minutes. Because the length of intervals is directly tied to the cost of the service, it is important to determine what downtime interval is acceptable. Generally prices range from free to $99.00 per month. Mission critical server packages normally range fall in the $30.00 - $60.00 per monthly range.

If you have a small business you may not need to purchase long intervals of testing. Those are usually best for larger corporations whose site or server performs mission critical functions. On the other hand, a site or server operating a hobby may not require monitoring at all.

Monitoring firms perform monitoring from outside your web site’s IT infrastructure in the same way that other people accesses your servers. By using this approach, it ensures that your servers are available to your visitors and items such as firewall are correctly configured. Depending on your business goals, monitoring can be a valuable resource and play a critical role in your online success.