What Are PHP Workers and Why Do They Matter for Your Website?

PHP workers are a key component of any PHP-based website or application. They handle the server-side processes that make dynamic websites work, such as retrieving data from a database or rendering user-specific content.

But what are PHP workers? Whether you’re running a WordPress blog, an eCommerce store, or a custom PHP application, they help optimize your website’s performance and ensure it runs smoothly under various traffic conditions.

Let’s learn what PHP workers are, how they function, and why they are an important part of hosting your website. Plus, we look at worker limits by hosting type so you can make the right decision for your hosting needs.

What Are PHP Workers?

PHP workers are the server processes responsible for managing PHP scripts that power dynamic websites and applications.

Without them, PHP cannot process the requests that power your site. Many websites use PHP, including WordPress, Drupal, Joomla, and almost every other dynamic website program.

These specialized background processes execute the PHP code that loads your website content, including pages, blog posts, and even eCommerce storefront content. The more PHP workers you have, the more concurrent requests your site can handle.

Here’s a better look at how these background computing processes function:

1. Handle PHP Requests: Every time a user interacts with a PHP-based site (e.g., loading a page, submitting a form, or querying a database), a PHP worker processes the request.
2. Execute PHP Code: Workers run the PHP scripts required to generate the desired output, such as retrieving content from a database or rendering dynamic content.
3. Return Responses: After completing the PHP execution, the worker sends the processed data back to the web server, which delivers it to the user.

Each PHP worker can handle one request at a time. If all workers are busy, additional requests are queued until a worker is available.

Ideally, each request should take no more than 250 ms to process. Optimal processing times are as low as 100 ms, meaning that each worker can execute between 4 and 10 requests a second on average.

The total number of workers per server depends on the system resources, but most have thousands available. However, some hosting companies set limits for the number of workers available based on your plan.

If you do not have enough workers to handle your concurrent PHP requests, visitors may experience delays or errors. Frequent delays like slow page load speeds or server errors can negatively impact conversions and SEO rankings.

Other Names for these PHP Processors

While PHP workers is the most common and widely understood name in web hosting discussions, they are sometimes referred to by other names depending on the context or hosting environment. Here are a few alternate terms and closely related concepts:

• PHP Processes: This term emphasizes that these workers are processes running on the server to handle PHP script execution.
• PHP-FPM Workers: In servers using PHP-FPM (FastCGI Process Manager), they are specifically referred to as FPM workers or PHP-FPM processes.
• Server-Side Processes: A broader term that encompasses all server-side tasks, including those handled by PHP workers.
• Concurrent PHP Requests: This term is used to describe the capacity of these workers to handle simultaneous tasks, often in the context of hosting plans.

How Do Websites Use PHP Workers?

PHP workers execute the code used to load dynamic websites based on WordPress, WooCommerce, Drupal, Joomla, and other content management systems (CMSs). Here are the key tasks that these PHP processors perform:

• Processing Requests: PHP workers process all of the requests needed to load websites built on content management systems like WordPress. They execute the PHP scripts that render the website theme and load the front-end website. They also run the code that powers plugins, embedded shortcodes, and widgets.
• Database Interactions: Dynamic websites use databases to store most of the content. PHP workers handle these database queries. This includes retrieving blog posts, product details, or user records, saving new data like pages, posts, and product listings, and performing complex searches for data-intensive applications.
• Real-Time User Interactions: Workers also manage real-time interactions such as searches for content or products, form submissions for sign ups or surveys, and AJAX background requests like refreshing content.
• eCommerce Operations: They are also an important part of an eCommerce store, handling shopping cart operations, check-out processes, and managing inventory levels and order statuses.
• Running APIs and Integrations: Websites often interact with third-party services via APIs. PHP workers respond to client-side applications and communicate with payment gateways, shipping APIs, or social media platforms.
• Background Tasks and Automation: They process automated tasks like sending email notifications, running scheduled tasks like creating reports or cleaning up databases, and managing batch processes like data imports and exports.
• Supporting Complex Web Applications: Advanced applications like customer portals, learning management systems (LMS), or SaaS platforms rely on PHP workers to handle user interactions and run server-side calculations.
• Error Handling and Logging: They also manage server-side error logging and diagnostics so you can track and record issues and return user-friendly error messages when things go wrong.

How Many PHP Workers Do You Need?

The number of PHP workers you need depends on your website’s traffic, complexity, and the nature of the tasks being handled.

Each PHP worker can handle one request at a time. If all workers are busy, additional requests are queued and users could face slower performance, load delays, or 429, 500, 503, or 504 errors.

Hosting companies often place limits on the number of workers available based on your plan. While 1 or 2 workers are usually enough for a basic, low-traffic website, WordPress sites typically need at least 4 to 8.

High-traffic sites like enterprise-level websites, membership sites, and news or media organizations will need significantly more PHP workers.

That said, you can limit your need for PHP processors by using caching. Caching optimizes performance by creating a snapshot of your website. Think of it kind of like a printout.

Instead of running the PHP scripts every time, your site loads cached content without relying on these workers. This makes your site more efficient, freeing up workers for more complex tasks.

How Does Caching Impact PHP Workers?

Caching significantly reduces the load on PHP workers by minimizing the number of PHP requests they need to process.

It stores pre-generated content as static HTML pages and serves it directly to users without running the PHP code. This reduces the need for workers to process repetitive tasks.

By serving cached content, PHP workers are free to handle tasks that require real-time processing for user-specific content like shopping cars or backend operations like form submissions or API calls.

Caching reduces the workload for regular server-side processes like loading site content, ensuring the best user experience. This reduces server-side processing time, increases page load speed, and limits site errors that can negatively impact your SEO.

Understanding PHP Worker Limits in Hosting Plans

When it comes to choosing the right hosting company and plan, you need to consider how these workers will impact your hosting experience.

From how long it takes your site to load to managing spikes in traffic, it’s best to choose an option with the highest amount of PHP workers available.

While the total number of workers available depends on the host and the plan you choose, here is a rough breakdown of what you should expect based on the type of web hosting you choose:

• Shared Hosting: Shared hosting typically comes with a limited number of workers, as server resources are shared among multiple users. Because of these low limits, shared web hosting is best for small websites or blogs with low traffic and limited dynamic content.
• VPS Hosting: VPS plans allow users to scale PHP workers based on their resource allocation. Growing websites with moderate to high traffic should consider VPS web hosting to keep up with the demand and prevent errors.
• Dedicated Hosting: Dedicated servers offer full control, enabling users to configure as many PHP workers as their server’s hardware can handle. Dedicated web hosting is best for resource-intensive websites or those expecting high concurrent traffic.
• Managed Hosting: Managed hosting providers often optimize PHP worker allocation for platforms like WordPress or Magento. A managed plan is best for users looking for hands-free hosting with performance optimizations built in.

Some hosting companies list the number of workers available based on the plan you choose. 5 to 10 PHP workers are average for entry-level plans, but you may see limits that are even lower.

Depending on the host, you may also be able to purchase additional PHP workers to boost performance as your website scales.

Common Errors If You Do Not Have Enough Concurrent PHP Processes

When there are too few PHP workers available to handle incoming requests, the server may struggle to process all tasks efficiently. This can lead to HTTP status errors that negatively impact the user experience.

The most common errors and status codes are 503, 504, 500, and 429. While all of them are caused by an overload of simultaneous requests, the exact error or status code depends on what causes the issue.

Here are the most common errors and status codes and what causes them:

HTTP 503 Service Unavailable

• Cause: This error occurs when the server is overwhelmed and unable to process new requests because all PHP workers are busy.
• Symptoms: Users see a 503 Service Unavailable message, indicating the server cannot handle their request at the moment.
• Implication: A temporary issue, but it signals the need for more PHP workers or better resource allocation.

HTTP 504 Gateway Timeout

• Cause: If a request waits too long in the queue for a PHP worker to become available, it times out and triggers a 504 error.
• Symptoms: Users see a 504 Gateway Timeout message, indicating the server did not receive a timely response.
• Implication: Indicates severe resource bottlenecks, often seen during traffic spikes or under heavy load.

HTTP 500 Internal Server Error

• Cause: If the server struggles with insufficient PHP workers or encounters an error due to resource limits, it may return a 500 error.
• Symptoms: Users see a generic 500 Internal Server Error message.
• Implication: While 500 errors are broad, they can signal server-side issues like overloaded PHP worker usage.

HTTP 429 Too Many Requests

• Cause: Some servers implement rate limiting to handle resource constraints, which can lead to a 429 error when too many requests hit the server simultaneously.
• Symptoms: Users are blocked from accessing the site temporarily with a 429 Too Many Requests message.
• Implication: Indicates your server can’t handle the current request volume, often tied to limited PHP workers.

All PHP-based websites rely on PHP processor workers to render and load those sites. All A2 Hosting plans include dynamic PHP workers to ensure the best and fastest website hosting available.

Whether you are a growing blog, eCommerce store, or enterprise web application, you get the resources necessary to ensure the best user experience. Plus, every A2 Hosting plan includes premium hardware, exceptional 99.9% uptime, and 24/7/365 in-house Gur Crew support.

Get the resources, speed, and support your website needs with A2 Hosting. Compare our hosting plans and launch a new site or migrate any existing site today.

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