1. When possible, opt for the quality, server-grade CPUs (i.e. 64-bit Intel Xeon dual or quad core)

2. The more RAM you have, the better. You can never go wrong by adding memory to your system.

3. Get large, fast hard drives, especially if you plan to run virtual private servers (VPS).

4. For large-scale sites, server redundancy is a good thing, if you can afford it.

5. Multi-core processors improve performance, but correlate the amount of processing power you get with your actual needs. In other words, there is no point in having a 64-core processor for a couple of blogs.

6. Find ways to save power, especially if you have to pay for it. Green servers will save you money and save the environment.

7. Remember that technology is constantly evolving. Plan on needing to upgrade in the future.

Photo Source: Flickr

1. When possible, rely on the distribution updates and repositories. Only add third-party software when absolutely necessary.

2. Periodically run fsck to check the file system.

3. Monitor system and service logs.

4. Disable unused services.

5. Periodically optimize MySQL databases.

6. Monitor CPU and RAM usage.

7. Optimize RAM and swap usage.

8. On larger servers, run the database server on a separate machine, optimize the servers for scalability, and consider using a CDN (Content Delivery Network).

Photo Source: Flickr

Answer: If your current server setup involves a 32-bit architecture or even just a 32-bit version of your operating system, the short answer is: you cannot. By design MySQL will not be able to use more than 4GB unless it is running on a 64-bit OS.

If you are running Linux, type ” uname -m ” from the command line to see whether or not you are using a 64-bit version. If you know for a fact that your server actually has 64-bit processors, you can reinstall Linux with a 64-bit kernel.

The other less-drastic measure you may be able to take is to install a PAE (Physical Address Extension) kernel, which will allow your server to access physical address space larger than 4 GB. Some distributions, such as CentOS offer PAE kernel packages that you can easily install.

Source: Webhostingtalk.com
Photo: Flickr

MinSpareServers 5
MaxSpareServers 10

MaxRequestsPerChild – This is the maximum number of requests a child process will receive before it is killed. Make sure this setting is not too low, or it will create unnecessary load on Apache when it restarts the child.

MaxRequestsPerChild 1000 (for 1GB of RAM, 10,000 for 2GB)

KeepAlive and MaxKeepAliveRequests – This determines how long TCP connections are kept open for requests. Setting this higher will speed up HTML and Image downloading, but it can also add stress to the server. Whether or not to use KeepAlive depends on the purpose of your server. For a hosting server with shared hosting accounts, KeepAlive will probably just add too much CPU intensive stress. For a server with a single site that serves a lot of documents and demands speed (something like a wiki), you might want to keep it on.

KeepAlive off (or on – your choice)

Apache configuration is stored in a file called httpd.conf or apache2.conf, and it most often stored in /etc/httpd or /etc/apache2. To edit the file, you can use “vi” or “nano”.

MaxClients

This setting defines the number of visitors you can have connected at once. You can calculate the visitor capacity your server can support by using this formula:

150 x number of GigaBytes of RAM

For example, a server with 2GB of RAM can have 300 MaxClients. 3GB can support 450. Make it high enough to prevent user timeouts but low enough to avoid causing the server to lockup. A high amount can also make your server an easy target for DoS (Denial of Service) attacks.

ServerLimit

Set this value to the same as MaxClients (i.e. SeverLimit = 150 x number of GB of RAM)

I will continue the series on Apache optimization throughout this week. You can also read your Linux distribution’s specific documentation on Apache to find out specifics, such as where the configuration file is stored.

Source: linuxstuffs.net

A good web host will list some of their extra available features, including prices. Here is a brief list of options you might want:

• cPanel or other control panel
• SSL certificates
• Additional IP addresses
• Load balancing for two or more servers
• Anti-virus protection for mail servers
• Routine backup storage
• Additional RAM
• Additional hard drive
• Windows Server 2008
• KVM over IP
• Additional badwidth/data transfer

For prices check your web host’s website.

Photo Source: Wikimedia Commons

The amount of burstable memory that can be used depends on the loads of the other VPS units sharing your parent server. If the other clients are using all available resources, little burstable RAM will be available. On the other hand, you may find you can use all or most of it if the other units are running far below capacity.

Answer: There is no simple answer to this question. Generally speaking, to virtualize an operating system you need at least as much RAM as is normally required to run the OS independently. Therefore, if your OS requires 512MB of RAM to run normally, it will require that in virtualization.

It is, however, not quite that simple. Depending on your application needs, server loads, and the amount of data being accessed and transferred, your needs could range from the low (512MB) to the high (4GB) or even beyond that.

Therefore, it is important to know exactly what you need and how much RAM you would normally need to run the applications you are trying to run. Some virtualization software also includes dynamic memory allocation so that you can set a base amount and allow the amount used to expand on an as-needed basis. As with anything that might tax your server’s load, use it wisely.

Photo: Flickr

If you see a spike in CPU usage, an usually high amount of RAM being consumed, or other such anomalies, you could have a runaway process. Simply put, it is a program that is no longer behaving and may even be unresponsive. Linux has a quick and dirty solution: kill. If you happen to know the exact process number, just type: kill 8889, or whatever the process number is. If that does not help, add the “-9” flag to force it:

kill -9 8889

You can also quickly kill off all instances of a program with “killall”. For example, if a program called “gamebot” is no longer functioning or is frozen, you would enter:

killall gamebot

Use “kill” sparingly, and be very careful with “killall”, but when the time to kill does arrive, you will know it and know what to do. For more information about “kill”, type “man kill” from the command line.

Photo Source: Flickr

Question: My PHP content management program “X” needs more RAM. How do I fix this?

Answer: Depending on your server setup and whether you have shared hosting or a dedicated server, you may or may not be able to change the allowed PHP memory usage. What happens is that PHP is setup to allow a certain amount of data to be sent over the web before it times out and give you an error. The default is usually 8MB, which is not enough for large databases.

The solution is to increase the memory allowance. Normally, if it is done server-wide, you simply edit the php.ini file and find something that looks like:

“memory_limit = 8M”

If you want a 32MB limit, simplyl change it to:

memory_limit = 32M

If you are using a shared hosting account, there are several methods that a web hosting provider can use to allow you to change the settings, while some might not allow it at all. Check their documentation and, if necessary, contact them.

Photo Source: Flickr