In previous parts, we have revisited some performance, scalability, and PHP tuning related issues and not in this part of PHP MySQL development series, which is broadly focusing on the scalability of web application we will try to discuss some important aspects of load balancing.
During our PHP MySQL development we create we application with massive data and tons of interactivities between the dynamic application and end users. These all definitely lead to exert loads on the server, which has to manage all requests all the time forth and back. It is good thing that we start with a single server to handle these all sorts of loads on the dispatch as well as in order to run the web application smoothly on each client.
Another important thing is that you need to scale the web application in order to manage extra traffic or some more traffic each time you come up with some fresh initiatives. Now, in such scenario, single server is not capable to manage heavy load all the time and we need to take help of multiple servers. Technically, we can’t connect multiple servers directly with the web application or can’t split them without any intermediary server with appropriate software and hardware.
This intermediary server acts as the load-balancing server and allocates traffic judiciously to the other multiple servers with different software and hardware. Here PHP is ideal web development language to do horizontal scaling. You need not to worry about the numbers of servers you add in load-balancing server. The obvious role of load-balancing server is to provide central point to manage all incoming requests and dispatching them to the appropriate server and then again redirecting the responses from the corresponding servers to the end users in a highly synchronous manner.
There are two kids of load-balancers. The first one is software load-balancers and second is hardware load-balancers. These software balancers are install on Linux bases machines in most of the cases and have their own peculiarities in terms of built in page output caching, some gzip type of compression and other many things we need in a modern server. The big fishes are Apache, Nginx and Squid like software to do effective load balancing. If you can’t afford big brands you have Perlbal like cheaper software to help you out for small to medium projects.
The second part is of hardware load balancers that have some custom built software to manage the various hardware counterparts of the load-balancing software. In present market, Citrix Netscaler and F5 BigIP are well-known versions of the hardware load-balancers and server as good security barriers or firewalls for your web application.
Today Cloud computing is serving as new dimension in the load balancing, but here you have some distinct benefits despite their software only nature. Those benefits are coming from the unique in-built mechanisms of handling load balance across the all-existing instances. Although, cloud base load-balancers are stiff means shows less flexibility, but superb in terms of easy setup and their maintenance in cost effective manners.
In short, if you need good solution for load balancing you need to monitor the ability of manipulation or making caching of the data across the servers and sort out the most appropriate solution for you.
Conclustion
We all know that most of our PHP MySQL web application development suffering from load-balancing problems when question of scaling of web application arises. Thus, finding hardware that is more suitable or software base solution is the need of the present hour. We have many software and hardware as well as Cloud based load-balancers in the market so we need to be careful in selection.
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