SpamAssassin won’t do much if it hasn’t been trained. While it does come with a few plugins enabled for DKIM, SPF, RBL, and content checks, SpamAssassin is limited unless you train its Bayesian filter. The Bayesian filter will compare past content from known spam and ham emails to determine the likelihood of spam. Bayes' theorem, named after 18th-century British mathematician Thomas Bayes, is a mathematical formula for determining conditional probability.
Are you curious about SpamAssasin’s sa-update tool and what it does? As with many other programs geared towards servers, there are additional tools that are run inside of cron jobs and used by administrators. Knowing what these tools do and how they work can help you better understand your server and fix issues down the line. The sa-update tool is used to pull new configuration files and rules from channels. These new files are used by SpamAssassin to classify emails as spam in addition to the Naive Bayes filtering.
Below is a glossary of terms often times used when discussing Virtual Private Servers, web hosting, and networking. Knowing what these following terms mean should help you navigate hosting provider websites and tutorials. Not all of the following terms are concrete in meaning and could be used to mean a slightly different concept. The glossary below is ordered alphabetically and tries to focus only on terms used when discussing virtual private servers.
Having a VPS provider that offers internal IP addresses and internal networking can greatly improve your app or website performance by removing the network latency between servers. In addition to improved performance, an internal IP address you can help improve your servers security by not publicly exposing services to the public. Keep in mind that some internal networks have other VPS clients on the same subnet. These clients can access your internal IP address.
Virtual Private Server providers that offer an API are a godsend. The need for an API really depends on how much control you need from your VPS provider outside of their website. As VPS providers start adding additional features, for instance configurable firewalls, API access then becomes more useful to help manage all of the additional services. There are many possible reasons why you would want API access to your VPS provider from simply expanding block storage on your server to creating new servers on the fly dynamically.
When managing any type of server, it’s generally wise to have a solution in place for when a server fails or when the server needs to be taken offline. When working on a high availability server setup, the question is how to quickly transfer activity from the failed or offline server to the backup server. One method is to use IP failover, which is the focus of this post. In short, IP failover is the method of moving the IP address of the failed server to the backup server, allowing requests to be handled by the backup server until the main server is once again functional.
Nothing seems as nerdy as purchasing a VPS server using Bitcoins that you mined with your custom rigs. Ever since bitcoins become popular, hosting and tech companies were some of the first to adapt to accepting the new currency. Since it may be difficult to find a Virtual Private Server provider that accepts bitcoins, this list was created to help narrow your search down. Below is a list of popular Virtual Private Server hosts that accept payment via Bitcoin.
Many hosting companies have a clear Acceptable Use Policy (AUP) that outlines the services they allow to run on their servers, or more importantly, the services the hosting provider does not allow. These policies exist for all types of hosting services, from shared hosting to dedicated servers. As long as you are using someone else’s network, servers, and data center, there are going to be restrictions. It’s important to check if the services you plan on running on your server are allowed before purchasing your hosting plan and configuring your server.
One complaint many new VPS owners have is the amount of work required to setup a new server. If you don’t have an automated system pre-configured that instantly setups a new server, you could end up spending a few days modifying configuration files, installing services, and testing your new server. One solution that users turn to if they only run a few servers is to use TurnKey Linux. Instead of installing an operating system such as Debian, Ubuntu, or CentOS, you would install the TurnKey Linux image that matches your server’s needs.
Security should be your top priority when you’re maintaining a server even if you’re not working with personal information. In addition to hardening your server and properly configuring all of your services, subscribing to mailing lists can help keep your server secure by keeping you up to date on the latest security flaws. It’s difficult to manually keep up with all of the software that runs on your server, hence why subscribing to at least your distribution’s security mailing list is important.