Welcome!

PHP Authors: Liz McMillan, Carmen Gonzalez, Hovhannes Avoyan, Lori MacVittie, Trevor Parsons

Related Topics: @DXWorldExpo, Java IoT, Linux Containers, PHP, Agile Computing, @CloudExpo

@DXWorldExpo: Article

How to Spruce Up Your Evolved PHP Application

Three performance improvement steps

Do you have a PHP application running and have to deal with inconveniences like lack of scalability, complexity of debugging, and low performance? That's bad enough! But trust me: you are not alone.

I've been developing Spelix, a system for cave management, for more than 20 years. It originated from a single user DOS application, and has now emerged into a web application with hundreds of users, used nationwide as the official cave directory in Austria.

Just as many software projects: Spelix evolved from MS DOS to PHP-powered Web 2.0 with increased demand for functionality and scalability

Recently I applied for a job at Compuware. For a presentation during my job interview I prepared a case study about how to monitor and improve performance of Spelix with dynaTrace, a tool in Compuware APM's suite. I found more hotspots than expected, and it was much easier than expected to resolve them. I also killed two birds with one stone: Spelix is really performing now and I've got a cool, new job.

Let me share with you my experiences in that process and the best practices I've applied to bring spelix.at to its current stage.

The Challenge of Software Evolution
When we start to design a new application we have the chance to consider data volume, number of users, traffic, all of these thoughts that drive us in selecting the proper architecture. But not many of us are able to follow that procedure, because we have to deal with a grown application. A system has emerged from a tiny set of tools and scripts, more and more functionality has been added over the years. Optimization processes often concentrate on the PHP core app to create performing database access, processing and content rendering, but that's not enough. Unfortunately other tiers are not included in these processes. Too often on the client side, the brush-up ends after designing a new frontend, using existing JavaScript plugins, and not thinking about application performance. But a slow database or browser code can dramatically slow down your application, even with an optimized PHP core.

In Spelix I have identified six major scopes for performance optimization:

  1. Database
  2. Server Side Data Caching
  3. Client Side Data Caching
  4. Network Traffic
  5. Browser / CDN Cache
  6. Server Side Session Handling

To be more digestible, this blog is split into two. This post focuses on the first three performance improvement steps and the next one focuses on the last three.

Step #1: Optimize Database Access
In the early stages of an application, it may not be relevant how your database access is designed. As long as the amount of data is low, a poorly designed query or missing indexes may not really affect overall response times. Therefore, database performance is rarely a topic that comes up in many cases. Once it has become an issue, it may be rather complicated to be handled. It's important to place enough value in your database design right from the start. Here are some of my lessons learned and best practices:

Interaction of Views & Indexes
I don't want to get into too much detail about creating indexes as many other articles have covered this. But it's rather important to understand when an index is not used: be careful when using views in MySQL!

When should you use views? Views are perfect to create complex queries and store them for further use. Views are commonly used to prepare data for presentation, or even for data pre-selection based on user access rights.

When should you avoid views? While a WHERE clause on a simple view may cause an index to be used, this could fail in complex view, even though the WHERE clause is on the primary key for the primary table. Once your query gets too complex, MySQL creates a temporary table for the result of the view, and then applies the query on top of the view, without any indexes to be used. Be alert when your view contains commands like GROUP_BY, ORDER_BY, or UNION. So what? My key advice on this is: when you create a view, define possible WHERE clauses and check the execution plan in the database by using the EXPLAIN command. If your WHERE clause is on a column in a table marked as select type "primary", you are on the save side to use the view. If it's "derived" or "dependent subquery", your query might not use existing indexes. It could be better to execute the query code from the application. If you have executed the SQL statements directly from your business logic, create a data access layer that contains your query code. Consider executing multiple SQL statements and merge the data in your PHP code rather than using complex joins that may spoil your indexes.

Check and Eliminate Redundant Statements
Check if your SQL executions are really necessary! You might have executed your statement in an earlier stage, is there really a requirement to run it again? Would it make sense to keep the data in your current context instead of re-requesting it? The following screenshot shows the database statements executed by the PHP Application.

A very good metric is "Executions per calling Transaction" which makes it easy to highlight statements, which are called several times, maybe too often per transaction. If that number is greater than 1, you might want to dig deeper into your code and try to optimize that. In this example "select * from sys2" reads the settings for the current user, which is not going to change permanently. There is no requirement to run this query redundantly.

What to look for? Find your query invocations in your code and avoid repetitive executions.

Optimizations? Depending on the type of information, consider caching your data in your transaction, session storage or overall server side cache, as described in the next section.

Seeing the actual SQL Statements in the context of the request makes it easier to optimize executions of database queries.

For steps 2 and 3, and for further insight, click here for the full article.

More Stories By Harald Zeitlhofer

Harald Zeitlhofer has 15+ years of experience as an architect and developer of enterprise ERP solutions and web applications with a main focus on efficient and performant business processes, usability and application design. As a Technology Strategist in Dynatrace's Centre of Excellence team he influences the Dynatrace product strategy by working closely with customers and driving their performance management and improvement at the front line. He is a frequent speaker at conferences and meetup groups around the world. Follow him @HZeitlhofer

Comments (0)

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


IoT & Smart Cities Stories
To Really Work for Enterprises, MultiCloud Adoption Requires Far Better and Inclusive Cloud Monitoring and Cost Management … But How? Overwhelmingly, even as enterprises have adopted cloud computing and are expanding to multi-cloud computing, IT leaders remain concerned about how to monitor, manage and control costs across hybrid and multi-cloud deployments. It’s clear that traditional IT monitoring and management approaches, designed after all for on-premises data centers, are falling short in ...
The deluge of IoT sensor data collected from connected devices and the powerful AI required to make that data actionable are giving rise to a hybrid ecosystem in which cloud, on-prem and edge processes become interweaved. Attendees will learn how emerging composable infrastructure solutions deliver the adaptive architecture needed to manage this new data reality. Machine learning algorithms can better anticipate data storms and automate resources to support surges, including fully scalable GPU-c...
A valuable conference experience generates new contacts, sales leads, potential strategic partners and potential investors; helps gather competitive intelligence and even provides inspiration for new products and services. Conference Guru works with conference organizers to pass great deals to great conferences, helping you discover new conferences and increase your return on investment.
Poor data quality and analytics drive down business value. In fact, Gartner estimated that the average financial impact of poor data quality on organizations is $9.7 million per year. But bad data is much more than a cost center. By eroding trust in information, analytics and the business decisions based on these, it is a serious impediment to digital transformation.
We are seeing a major migration of enterprises applications to the cloud. As cloud and business use of real time applications accelerate, legacy networks are no longer able to architecturally support cloud adoption and deliver the performance and security required by highly distributed enterprises. These outdated solutions have become more costly and complicated to implement, install, manage, and maintain.SD-WAN offers unlimited capabilities for accessing the benefits of the cloud and Internet. ...
Business professionals no longer wonder if they'll migrate to the cloud; it's now a matter of when. The cloud environment has proved to be a major force in transitioning to an agile business model that enables quick decisions and fast implementation that solidify customer relationships. And when the cloud is combined with the power of cognitive computing, it drives innovation and transformation that achieves astounding competitive advantage.
SYS-CON Events announced today that Silicon India has been named “Media Sponsor” of SYS-CON's 21st International Cloud Expo, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Published in Silicon Valley, Silicon India magazine is the premiere platform for CIOs to discuss their innovative enterprise solutions and allows IT vendors to learn about new solutions that can help grow their business.
DXWorldEXPO LLC announced today that "IoT Now" was named media sponsor of CloudEXPO | DXWorldEXPO 2018 New York, which will take place on November 11-13, 2018 in New York City, NY. IoT Now explores the evolving opportunities and challenges facing CSPs, and it passes on some lessons learned from those who have taken the first steps in next-gen IoT services.
SYS-CON Events announced today that CrowdReviews.com has been named “Media Sponsor” of SYS-CON's 22nd International Cloud Expo, which will take place on June 5–7, 2018, at the Javits Center in New York City, NY. CrowdReviews.com is a transparent online platform for determining which products and services are the best based on the opinion of the crowd. The crowd consists of Internet users that have experienced products and services first-hand and have an interest in letting other potential buye...
Founded in 2000, Chetu Inc. is a global provider of customized software development solutions and IT staff augmentation services for software technology providers. By providing clients with unparalleled niche technology expertise and industry experience, Chetu has become the premiere long-term, back-end software development partner for start-ups, SMBs, and Fortune 500 companies. Chetu is headquartered in Plantation, Florida, with thirteen offices throughout the U.S. and abroad.