This project was a programming test for interview at a company, I did it only for using it as a portfolio about how I done projects with Phalcon and what is my insight about performance in PHP Programming. the original test case described bellow. I completed all two goals and all two bonuses. you can clone the project and see the performance results. the only change that you might keep in mind that the stats url changed from http://localhost/stats.php to http://localhost/stats
If you find the company that use this test for their interviews please don't copy any part of this project. it is important to be your self at interviews to have a success career not only a success interview.
We expect you to be familiar with git, Vagrant and VirtualBox.
The question and initial code is provided to you on this git repository.
The provisioning facility of vagrant will give you a box with the necessary software to get you started.
Your solution should be committed back into this repository like you would do in a normal project.
You can commit and push as many times as you want.
Please make sure you update the provisioner in case your solution requires extra packages, database schema changes, code/dependencies initialization or service startup.
Your response will be pre-evaluated by an automated system by doing:
git clone <this repository url>vagrant up --provision- run checks against index.php, stats.php and database.
Ensure those steps work as you would expect before asking for your answer to be evaluated.
One of the things we definitely do want to see are unit tests, so please do not forget those.
Among others, our company provides a variety of services to which a Client can subscribe by simply sending a subscription request via SMS to a so-called shortcode. For example, the Client sends an SMS with subscription request 'ON LEARNING' to shortcode 32788 to subscribe to our mobile learning services.
The industry term for such SMS'es is MO, which stands for Mobile Originated. Daily we receive and process millions of MO's which are sent to us by the telecom gateway through our MO API.
All of this is done in by the code that is provided to you in this talent test.
An example of a call through our MO API could look like this:
http://localhost/index.php?msisdn=60123456789&operatorid=3&shortcodeid=8&text=ON+GAMES
Your first goal is to transform this smelly code into production grade, quality code that follows modern software development practices. We can't emphasize enough the importance of this!
You will also notice that this code doesn't perform well. The registermo is inherently slow and you may
assume there is absolutely nothing you can do to improve the registermo command.
Can you improve the design in such a way that it can handle several thousands of requests per second?
There is also a stats.php file that is called periodically by our monitoring system to provide it with relevant performance statistics of our MO API.
The problem we are facing is that it has become very slow, something which seriously impacts our monitoring system.
Your second goal is to solve this problem and make sure that stats.php takes less than one second to run.
A simple way of checking the performance of the MO API is to use Apache's ab tool, like this:
ab -n 1000 -c 10 "http://localhost/index.php?msisdn=60123456789&operatorid=3&shortcodeid=8&text=ON+GAMES"
In order to better integrate with our monitoring tools, we need a way to know how many MO's have been received but not yet processed.
Can you provide a command line tool that, when executed, prints out a single integer: the number of MO's received but not yet processed?
Occasionally we get a wave of problematic MO's that fail to be processed.
To ease administration, can you provide a command line tool to clear (remove) all those MO's that have been received but not yet processed so that we don't waste time and system resources trying to process them?
- What's this binary
registermodoing?
Don't worry about this. This is a placeholder for external process and API calls we have no control over.
To rephrase what was stated in Goal 1, you are not allowed to change this binary in any way. Do not spend your time on it.