PHP handlers are the certain types of programs that load the PHP codes library on your Apache web server. PHP handlers see how these libraries are being loaded on the server. If you want to run a website with Php script then you need to execute the PHP codes on server. Or in other words we can say that php handler is a implementation which delivers the code library on server and works as a link between server and php codes. Since each handler provides the different files which generally affects the performance of your Apache server. So it is better to know about a handler to choose according to a particular situation.
Types of PHP handler:
php handler can be classified into four kinds as given below.
DSO: DSO is the fastest handler among all handlers. It is saved as a default setting on the server. The main advantage of this handler is the speed and is the best for the servers which run one or two sites having huge content matter because it needs very low memory requirements. The major demerit of this handler is security issue. All files that are uploaded by php scripts will be owned by user “nobody”. So in DSO all sites run under the one user so security concerns may take place. If a hacker is able to exploit the php script then he can generate the some files and it enables the intruder to edit the files outside the user account.
SuPHP: Although suPHP is slower than DSO but it is more secure than DSO. It interprets the php as the owner of domain instead of nobody user. Since the php files are interpreted by different user so chances of vulnerabilities are very few. Hence it provides the unquestionable security to the servers.
FCGI: It has a high performance value over CGI and can be used with an eAccelators or APC to avoid speed issues.
CGI: This handler is discarded because it is neither fast nor secure. It runs php as CGI module weather the SuEXE is enabled or not.