Why Backups Are Essential
By Bock | November 14, 2007
One thing most web site owners have little time for is… anything! Anything other than focusing on their site content and the business or service it supports and the information it provides, that is. That means that administration often suffers, as it frequently must. There’s only so much time in the day.
But the one thing that you should never let slide are backups. They are like insurance. You rarely need it (you hope), but when you do you need it very badly.
Performing regular backups - and testing them - doesn’t have to be a nightmare. A little bit of forethought and effort and they can be automated to a high degree. And, they should be tested from time to time. Even when a backup appears to have gone without a hitch, the only way to know whether it’s of any value is to attempt to restore the information. If it can’t be restored, the backup is worthless.
Even when the web hosting company provides the service, there is still some planning involved for the site owner. Hosting companies often rely on one or both of two methods. They backup everything (called a full backup), then backup anything which has changed since the last full backup (called an incremental backup).
Of special interest are any configuration files that have been tailored. If you’ve modified the default installation of a software package, you want to be able to recapture or reproduce those changes without starting from scratch. Network configuration files, modifications to basic HTML files, CSS style sheets and others fall into the same category.
If you have XML files, databases, spreadsheets or other files that carry product or subscriber information - about items purchased, for example, or people who signed up for a newsletter - those should get special attention, too. That’s the lifeblood of your business or service. Lose them and you must start over. That can break your site permanently.
It should go without saying that all HTML and related web site files that comprise visible pages should be backed up regularly. It isn’t necessary to record every trivial change, but you can tailor backup software to exclude files or folders. Usually they’re so small it isn’t worth the trouble. But in some cases those small changes can add up in scenarios where there are many thousands of them.
Here again, the backups are worthless if they can’t be used. Even if the hosting company charges for doing so, it’s worthwhile to test once or twice a year at least to ensure the data can be restored. That’s especially true of database backups, which often involve special software and routines. Database files have a special structure and the information is related in certain ways that require backups be done differently.
Developing a backup strategy can be straightforward. Start simply and review your plan from time to time, modifying it as your site changes and grows. But don’t neglect the subject entirely. The day will come when a hard drive fails, or you get hacked or attacked by a virus, or you accidentally delete something important. When that day comes, the few minutes or hours you spent developing and executing a backup plan will have saved you days or weeks of effort.
Topics: Administration | No Comments »
Databases, What Are They and Do You Need One?
By Bock | November 14, 2007
‘Database’ is one of the most commonly used terms that one encounters in web site design. Yet, what they really are and whether they’re essential is often not clear to novices.
A database is a collection of organized data, stored in files that have a specific structure. It’s that organization and structure that allows for easy and rapid storage and retrieval.
The need for a database generally only arises when you have a certain amount of information and that information needs to have some structure. If you have a half-dozen names and addresses to store, a database is usually overkill. If you have a blob of data with no relationships between any of the items in that blob, maintaining a database is usually more trouble than it’s worth.
Maintain a database? Yes, like other complex systems a database, to be effective, needs to be designed properly at the outset then kept ‘tuned’ for good performance. The alternative is to gradually allow the database to become more and more disorganized. That leads to difficulty in use, poor speed of retrieval and more frequent failures.
With MySQL, Access or MS SQL Server, the three most common choices of database product for web sites today, setting up a database is relatively simple. Even those with limited technical skill can get one up and running just by following some simple instructions. But some thought should be given to how you want the information organized, and to maintaining the system during its lifetime.
Suppose you have a set of names, addresses, email addresses, products purchased, date purchased and amount. If you have only a few dozen records it matters very little how these pieces are arranged and related. A database usually isn’t even warranted in this scenario. Once you have several thousand or more records, it matters a lot. Speed, the ease of expanding the set of attributes (like adding, say, product category), and other issues come into play.
Even those with little technical expertise, but a willingness to exert logical thought and invest some time, can build a very robust database. Think about how you would organize a set of data (called ‘tables’). Should Name, Address, and Product be in the same table? Or should the personal information be stored in one table and any product information (product, price, …) in another?
Some experimentation may be needed to get it right, but the choices have an impact on how easy the tables are to maintain. It also affects the speed with which programs can fetch old data and store the new.
Having a database also introduces new maintenance issues for the server administrator, since backups usually need to be done differently. Recovering a failed database is usually more complicated than simply re-copying files from yesterday. Ask your hosting company what tools and skills they have for dealing with any database system you consider.
It’s true that introducing a database creates more complexity and the need for additional thought and administrative effort. At a certain level, professional expertise will be needed. But clearly the advantages outweigh the costs in many cases. Companies large and small eventually use databases to store and organize data. At some point, you may be fortunate enough to be one of them.
Topics: Databases | No Comments »
Is a Dedicated Server Worth What You Pay?
By Bock | November 14, 2007
In reviewing web hosting plans, many web site owners are faced at some point with the decision of whether or not to pay for a dedicated server. A dedicated server is one which holds your site(s) exclusively. It’s not shared with other sites. You then have the option to put one site or many on that piece of hardware.
But the decision is never easy. There are multiple considerations to take into account, far beyond just the higher dollar outlay that inevitably accompanies a dedicated server option.
Performance is (or should be) a prime consideration for the majority of site owners. Studies show that when a page doesn’t load within about 10 seconds or less, almost everyone will give up and go elsewhere. The delay may be caused at any of a hundred different points in the chain between the server and the user. But often, it’s the server itself.
In any case, it’s important to eliminate the server as a possible bottleneck, since it’s one of the few points over which the site owner can exercise some control.
That need for control extends further than just performance, however. Other aspects of the user experience can benefit or suffer from server behavior. Security is a prime example. With the continuing prevalence of spam and viruses, a server can easily get infected. Having only your site(s) on a single server makes that issue much easier to deal with.
With fewer sites on a server, there is less likelihood of getting infected in the first place. Also, since you will place a higher value on security than many others, it’s easier to keep a dedicated server clean and your site well protected. You can use best practices in security to fortify your site. Having other sites on the server that you don’t control raises the odds that your efforts are for nothing.
One way your efforts can get watered down is through IP address sharing. Less sophisticated hosting services will often assign a single IP address to a single server and multipe sites. That means your site is sharing the same IP address with other domains. That leaves you vulnerable in several ways.
Virus or spam attacks may target a particular IP address. If you have the same one as another site, one that is more likely to attract hostile intentions, you suffer for and with someone else.
In other cases an IP address range is assigned to the server, with each site receiving its own address from within that range. Though better than the one IP:server scenario, this still presents a vulnerability. Many attacks try a range of IP addresses, not just a single one.
But even legitimate sources can give you trouble when you share an IP address or a range. If another site engages in behavior that gets it banned, you can suffer the same fate if they ban the address or range. If the miscreant that shares your server/IP address or range is himself a spammer for example, and gets blacklisted, you can inadvertently be banned along with him. Using a dedicated server can overcome that problem.
There’s a certain comfort level in knowing what is installed on the server you use, and knowing that you alone put it there. But a dedicated server option may require increased administration on your part. If you’re not prepared to deal with that, you may have to pay still more to have your dedicated server managed by someone else.
All these factors have to be weighed carefully when considering a dedicated server plan.
Topics: Servers | No Comments »
Sharing A Server – Things To Think About
By Bock | November 14, 2007
You can often get a substantial discount off web hosting fees by sharing a server with other sites. Or, you may have multiple sites of your own on the same system. But, just as sharing a house can have benefits and drawbacks, so too with a server.
The first consideration is availability. Shared servers get re-booted more often than stand alone systems. That can happen for multiple reasons. Another site’s software may produce a problem or make a change that requires a re-boot. While that’s less common on Unix-based systems than on Windows, it still happens. Be prepared for more scheduled and unplanned outages when you share a server.
Load is the next, and more obvious, issue. A single pickup truck can only haul so much weight. If the truck is already half-loaded with someone else’s rocks, it will not haul yours as easily.
Most websites are fairly static. A reader hits a page, then spends some time skimming it before loading another. During that time, the server has capacity to satisfy other requests without affecting you. All the shared resources - CPU, memory, disks, network and other components - can easily handle multiple users (up to a point).
But all servers have inherent capacity limitations. The component that processes software instructions (the CPU) can only do so much. Most large servers will have more than one (some as many as 16), but there are still limits to what they can do. The more requests they receive, the busier they are. At a certain point, your software request (such as accessing a website page) has to wait a bit.
Memory on a server functions in a similar way. It’s a shared resource on the server and there is only so much of it. As it gets used up, the system lets one process use some, then another, in turn. But sharing that resource causes delays. The more requests there are, the longer the delays. You may experience that as waiting for a page to appear in the browser or a file to download.
Bottlenecks can appear in other places outside, but connected to, the server itself. Network components get shared among multiple users along with everything else. And, as with those others, the more requests there are (and the longer they tie them up) the longer the delays you notice.
The only way to get an objective look at whether a server and the connected network have enough capacity is to measure and test. All systems are capable of reporting how much of what is being used.
Most can compile that information into some form of statistical report. Reviewing that data allows for a rational assessment of how much capacity is being used and how much is still available. It also allows a knowledgeable person to make projections of how much more sharing is possible with what level of impact.
Request that information and, if necessary, get help in interpreting it. Then you can make a cost-benefit decision based on fact.
Topics: Web Hosting | No Comments »
Changing Web Hosts, Pitfalls and Planning
By Bock | November 14, 2007
At some point, nearly everyone finds it necessary to change web hosts. It may be just a migration to another server, or it may be changing web hosting companies entirely. Either way, the process is fraught with potential dangers. But there are ways to minimize the odds of problems and maximize your changes of a smooth migration.
Plan, plan, plan.
Make a very detailed list of everything that is on your current system. Review what is static and what changes frequently. Note any tailoring done to software and files. Be prepared to remake them if the systems aren’t transferred properly or can’t be restored. Keep careful track of all old and new names, IP addresses and other information needed to make the migration.
Backup and Test
Backup everything on your system yourself, whenever possible. Web hosting companies typically offer that as a service, but the staff and/or software are often less than par. Often backups appear to go well, but they’re rarely tested by restoring to a spare server. When the time comes that they’re needed, they sometimes don’t work.
Do a dry run, if you can. Restore the system to its new location and make any needed changes. If you have the host name and or IP address buried in files, make sure it gets changed.
This is often true of databases. SQL Server on Windows, for example, picks up the host name during installation. Moving a single database, or even multiple ones, to a new server is straightforward using in-built utilities or commercial backup/restore software. But moving certain system-related information may require changing the host name stored inside the master database. Similar considerations apply to web servers and other components.
Accept Some Downtime
Be prepared for some downtime. Very few systems can be picked up, moved to another place, then brought online with zero downtime. Doing so is possible, in fact it’s common. But in such scenarios high-powered professionals use state-of-the-art tools to make the transition seamless. Most staff at web hosting companies don’t have the skills or the resources to pull it off.
Prepare for Name Changes
One aspect of moving to a new host can bedevil the most skilled professionals: changing domain names and or domain name/IP address combinations.
When you type a URL into your browser, or click on one, that name is used because it’s easier for people to remember. www.yahoo.com is a lot easier to remember than 209.131.36.158. Yet the name and or name/IP address combination can (and does) change. Still, specialized servers called DNS (Domain Name System) servers have to keep track of them. And there are a lot of them.
There may be only two (rarely) or there may be a dozen or more DNS servers between your visitors’ browsers/computers and your web host. Every system along the chain has to keep track of who is who. When a name/IP address changes, that pair has to be communicated to everyone along the chain, and that takes time.
In the meantime, it’s possible for one visitor to find you at the new place, while another will be pointing to the old one. Some amount of downtime will usually occur while everything gets back in sync.
The Little Gotchas
But even apart from name and IP address changes, there are a hundred little things that can, and often do, go wrong. That’s not a disaster. It’s just the normal hurdles that arise when changing something as complicated as a web site and the associated systems that underlie it.
Gather Tools and Support
Having an FTP program that you’re familiar with will help facilitate the change. That will allow you to quickly move files from one place to the next to do your part to get the system ready to go or make repairs.
Making the effort to get to know, and become friendly with, support staff at the new site can be a huge benefit. They may be more willing to address your problem before the dozen others they have to deal with at any given moment.
Ok. On your mark. Get ready. Go.
Topics: Administration | No Comments »
