As you remember, each server response includes status and headers. In the previous article, we listed all the server response statuses and named the most important of them. This time we will speak about server response headers. Let’s go back to the response example we used earlier: More →
Moving to a new domain is always associated with a number of difficulties. Firstly, you need to transfer the files and the database so that the site works without interruption. Secondly, it is necessary to carry out a number of actions aimed traffic and ranking maintenance. Experienced specialists can perform this operation in their sleep. But first-time webmasters have a lot of questions – and we try to address them in our article. More →
In October, 2016, critical Linux kernel vulnerability was discovered. The vulnerability called Dirty COW is related to copy-on-write (COW) kernel memory processing mechanism. Actually, it exists in Linux kernel since 2007.
Vulnerability refers to privilege escalation. Exploiting Dirty COW bug, unauthorized local users More →
As a rule, to solve problems of the server you need to know what happened to it before. Here, monitoring systems come to the rescue. Today there is a wide range of useful monitoring systems (and Nagios is regarded to be the most popular one). Among them Munin should be marked out.
Munin is convenient and easy-to-configure tool of server performance monitoring. It has a large number of useful plug-ins available right away after installing. Its extensible functionality allows to monitor virtually every server characteristic: load average, network, CPU loading, memory usage, postfix, exim4, mysql and many more. More →
Although Dropbox is extremely user-friendly, many companies do not use it for security reasons. As a result, Dropbox analogies operating within an enterprise network start to appear on the market. One of them is Seafile.
More precisely, Seafile is a Dropbox-like cloud data store that allows users to store their data on cloud servers and share information with other users on the Internet. In addition to the basic functions of remote server storage and data synchronization, Seafile provides flexible opportunities for content sharing and collaboration. Let’s examine Seafile advantages in detail. More →
Shellshock (or Bashdoor) is a series of software vulnerabilities found in GNU Bash in September, 2014. The level of danger currently assigned to this vulnerability by NVD is ‘10 of 10’; moreover, it needs no authentication to use Bash through CGI scripts. Vulnerability affects all Bash versions of nearly 25 years (including 4.3). Alas, the vulnerability can be preserved in the future versions. Let’s clarify the essence of the bug.
The main danger is the ability to arbitrarily set the environment variables in the bash shell. The problem appears when the bash shell continues to process commands after the function definition, so it allows to perform code injection attack. Thus, at the moment bash interpreter processes some code line any command can be executed. In the context of the Web, it can be done through such mechanism as CGI script (not necessarily via a request header). Keep in mind that the path and query string can also be a potential attack vector. More →
Network load balancing is a method of allocating tasks across multiple network devices (e.g. servers) in order to optimize resources usage, reduce the request processing time, as well as to provide fault tolerance (redundancy).
Load balancing can be used to empower the server farm. It also allows to continue server operation even when several execution units are out of order.
To achieve maximum bandwidth and resilience you have to keep several important rules. More →
Many people (and not only newbies) confuse memcache with memcached because of the names similarity. Let’s investigate the difference between these popular tools.
Some users think that memcache and memcached are both caching services, but it is not true. In fact, there is only one hash table based data caching service, and it is called Memcached. Using a client library it allows you to cache data in RAM of available servers.
But what is memcache then? More →
Network protocol is a set of rules that allows to connect and exchange the data between several network enabled devices. Nowadays there are many popular network protocols, but this article is devoted to FTP and its safe releases, SFTP and FTPS.
FTP (or File Transfer Protocol) is data transfer protocol that uses a special file server that allows users to exchange text and binary files with any networked computer. After connection is set the user can upload files to the remote machine and download data to his/her local computer.
Created in 1971, FTP is one of the oldest application protocols More →
Server cracking is one of the most vital Internet issues today, that especially concerns sites with high traffic or profitability. In fact, this is the problem every internet business owner faces the prospect of. That is why it is highly important to take specific measures to stop hackers beforehand.
But how to avoid hacking and computer viruses? To protect VPS from hacking you have to fully control it, carefully adjust its settings, and monitor system changes. Luckily, modern technologies can greatly lighten your work! More →