What Is The Cache Hit Ratio and The Most 3 Quick Tips to Increase It?

The cache hit ratio is calculated by dividing the number of cache hits by the total number of cache requests (the sum of the number of cache hits and the number of cache misses). Finally, that result is multiplied by 100 to get the percentage.

The cache hit ratio is one of the metrics in the cache memories, used to determine the cache’s efficiency. A Content Delivery Network (CDN) stores your website’s content in the proxy/ edge server for fast delivery to your users worldwide. 

By measuring the cache hit ratio, we can measure how many content requests your cache can effectively deliver. Here, we will explain what the hit ratio is and how to measure it. We will also look at three quick tips to increase the cache hit ratio. 

What is Cache and How Does it Work?

Before discussing the cache hit ratio, you need to understand what a cache is and the importance of using a caching mechanism on your website & how cache works.

A cache is a temporary memory that stores your website’s data or static content so that when a user visits your webpage, that content will render much faster. By using a cache you can boost your website’s load time for a better user experience.

Let’s understand the cache mechanism in simple words. When a user visits your website for the first time, the browser loads the static resources and stores them in the browser cache. The next time that user revisits your website, the stored resources are served from the browser cache.

If the requested content is not available in the browser cache, then the HTTP request will go to the CDN cache. If that requested content is present in the CDN cache, then it will be served from there.

Finally, that HTTP request will go to the origin server. If the content is present in server memory, it will be served from the server cache. Otherwise, it will be served from the hard disk or storage. 

Let us understand this cache mechanism with an example.

• A visitor opens the cache vs cookies blog on RabbitLoader.com.
• If images are present in the cache, it will serve from the cache in RabbitLoader, increasing the cache hit ratio.

• Otherwise, it will serve from the origin server (Hostinger). This is known as a cache miss.

What is the Cache Hit and Hit Ratio?

A cache hit happens when a user requests data or content from a cache and that cache is able to fulfill that HTTP request, indicating the data/ content is successfully served from the cache. 

The cache hit ratio is an important metric for CDNs that tells how efficiently a CDN can serve the content that is stored in the cache. It’s measured as the number of cache hits divided by the total HTTP request (cache hit and cache miss).

What is the Cache Miss and Miss Ratio?

A cache miss ratio occurs when the requested content or data is not available in the CDN cache. Thus, the requested content will serve from the origin server instead of the CDN cache.

The cache miss ratio is calculated as a percentage of the number of cache misses and the total number of cache hits and cache misses. 

The Example of Cache Hit and Cache Miss

Now you have a brief knowledge of cache hit and cache miss. Now, you will understand with an example. 

RabbitLoader publishes a new blog on its website, and you are the first visitor to this blog for an edge location. So, when your browser sends an HTTP request for the content of this blog, the content will be sent from the origin server and loaded in the CDN server. Because the content is not available in CDN, a cache miss occurs in CDN.

The next time anyone opens this blog, the content can be served from the nearest edge server instead of the origin server. This can be described as a cache hit.

How to Calculate the Cache Hit Ratio and Cache Miss Ratio?

As mentioned earlier, you can calculate the hit rate by dividing the number of cache hits by the total number of cache requests (the sum of the number of cache hits and the number of cache misses). Finally, that result is multiplied by 100 to get the percentage.

The easiest way to calculate hit ratios is by using the below formula: 

Cache hit rate (the number of cache hits/ Total cache requests)*100

To calculate the cache miss ratio, you need to divide the number of cache misses by the total number of HTTP requests and then multiply by 100.

Cache miss rate= (the number of cache misses/ (Total cache requests)*100

Let’s understand with an example. Let’s say the total number of cache requests is 50, and the cache hits are 26. 

Cache hit rate= (26/50)*100

                      = 52%

Cache miss rate= (100-52)%

                          = 48%

What is the Ideal Cache Hit Ratio?

By getting the cache metrics: cache hit rate and cache miss rate, you can determine the CDN performance. If your website is made up of lots of static content, then your cache hit rate should be greater than 95 %

You need to keep in mind that if your website has a lot of dynamic content, it may have a lower cache hit ratio.

3 Ways to Increase Cache Hit Ratio for Your Website 

As you can see, the cache hit rate determines the cache performance for your website. Therefore, If the cache hit rate is low for your website, you need to increase it to boost your website’s performance. Let’s list the 3 most common ways to increase this hit rate:

• Set up a cache-control header based on your website’s requirements
• Increase the cache size and optimize the cache usage
• Cache invalidation

Set Up a Cache-Control Header Based on Your Website’s Requirements

By cache-control header, you can set the caching rules for optimizing your website’s data/ content serving. Here we will explore some cache-control header rules that include:

• no-cache indicates that though the requested content is available in the edge cache server, the HTTP response needs to be validated from the origin server before serving it.  

• max-age indicates the amount of time that the cache can store your website’s content. It can be measured in seconds.

• private tells your resources can be only stored in a private cache.

Optimize the Cache Size and Cache Usage

Optimizing the cache size and selecting the content to cache properly can increase your cache hit ratio. You need to ensure that the frequently accessed resources are stored in the cache by prioritizing high-demand resources. 

Cache Invalidation 

To increase the hit ratio, you need to ensure that your cached content remains up-to-date. To avoid stale content, you must invalidate or refresh your cache by setting up the cache control:max-age. 

How RabbitLoader Will Help You to Increase Your Cache Hit Ratio?

As you can see, the above ways are time-consuming. Being from a non-tech background, these strategies can look impossible to implement. But don’t panic. RabbitLoader has the solution. Let’s explore how RabbitLoader works to improve your cache hit ratio.

• You can easily install Rabbitloader to optimize your website’s performance, it will cache your website’s assets such as CSS sheets, Scripts, images, and HTML files for the right amount of time. Therefore, by storing your website’s assets, RabbitLoader will increase your website’s cache hit ratio and reduce the load on your origin server.

• RabbitLoader has a premium Content Delivery Network (CDN) with 300+ PoPs worldwide. By using RabbitLoader, you can ensure that your content is up-to-date (stale-free). It will also help you reduce your network latency with its 300+ PoPs.

Persistent Object Cache: How it Can Improve Your Website Performance

A persistent object cache is a powerful tool that significantly improves your WordPress website’s pagespeed performance. 

Your users expect a fast-loading website, but seeing a slow WordPress website can ruin their experience and increase their bounce rate. A Persistent Object Cache can be used to solve this issue.

You might be tempted to use Persistent Object Cache on your website, but first learn about persistent object cache in detail, how it works, and the benefits of using it in your WordPress website. Also, we will discuss the best practice for using persistence object cache – Redis and Memcached.

What is a Persistent Object Cache?

Your wordpress website consists of PHP objects. These PHP objects are constantly built, initiated, and removed by your memory manager. These actions can overload your server, leading to a slow WordPress website. This issue can be solved by a persistent object caching mechanism.

Before going to the persistent object cache, you first need to understand what object cache is.

What is Object Cache?

An object cache is a built-in object-caching mechanism that is used to store the database query results in cache memory so that, the next time a query is needed, it can be quickly fetched from the object cache instead of querying the original database again. 

A persistent object cache is known as a specialized server, such as Redis or Memcached, that is used to store your data in a way that persists beyond a single request or an entire session’s duration.

In simple words, a persistent object cache is a server side caching technique where data is stored in a persistent storage such as an in-memory data structure store. It allows for a quicker retrieval of the data query.

For example, imagine your WordPress website has high organic traffic. Your website’s pagespeed will decrease due to server overloading. Implementing a persistent object caching technique can solve this issue by caching frequently accessed data queries in RAM.

How Does an Object Cache Work?

An object cache helps reduce frequently repeated queries by caching the query results from the first request. Let’s examine how it works in just three steps.

1. Requesting  Data

When your visit requests for certain data on your website for the first time, the browser sends an HTTP request to your web server. 

2. Check Cache

After receiving the HTTP request, it will check if the requested data is available in the object cache. This checking is usually performed by using a unique key. This key is based on the URL, database query, or other unique identifier.

3. Cache Hit

If the requested data is present in the object cache, then it will directly be sent to the user. This process is known as cache hit.

If the requested data is not there in the object cache, then it will be served from the original database. This is known as a cache miss.

What is the Cache Hit Ratio?

The cache hit ratio monitors a cache’s efficiency. It measures how successfully an object cache serves the requested data to your user.

The cache hit ratio is defined as the percentage of the total number of cache hits to the total number of requested data: cache hit & cache miss.

See more: BF Cache

Let’s understand with an example.

Difference Between Persistent Object Cache and Non-Persistent Object Cache

Let’s see the different types of object caching. The object cache is categorized into two types.

1. Persistent Cache
2. Non-Persistence Cache

What are the Benefits of Using a Persistent Object Cache on Your Website

Let’s see the two most important benefits of using a persistent object cache on your WordPress website.

1. Reduce Your Database Workload

A persistent object cache is used to minimize the database queries by storing frequently accessed data in memory. Thus, it drastically reduces the database load, leading to a faster-loading WordPress website.

2. Decoupling from External System

A persistent object cache provides buffer layers that allow the application to run even if the database ( primary data source) is slow or temporarily unavailable. Thus, it will improve your WordPress site’s performance.

How Can You Check if Your WordPress Site Needs a Persistent Object Cache

A persistent object cache may not be required for all WordPress websites. But, a persistent object cache improves your website’s pagespeed performance, Only if your large website has lots of visitors.

To see whether your WordPress website requires a persistent object cache or not, you need to check your site health status by following the below steps:

1. After logging into your WordPress dashboard, click on the Site Health screen link.

2. Wait for some time to finish the loading.

3. After waiting for some time, you can see some suggestions to improve your site’s performance.

4. Click on Performance. In this tested website, a persistent object cache is required.

How to Use Persistent Object Cache With WordPress

• Redis

Redis (Remote Dictionary Server) is an open-source in-memory caching solution for data structures such as lists, strings, and hashes. Redis object cache is especially useful for session storage, database query caching, and other similar uses.

There are a lot of WP caching plugins available that support Redis object cache such as Redis Object Cache, Object Cache Pro, WP Redis, and so on. Let’s see the installation process of the most popular Redis cache. 

Check also: Web Caching Strategies

How You Can Install the Redis Object Cache Plugin?

To install the Redis cache in your WordPress site, you need to follow the steps:

Prerequisite:  

• RAM: A minimum of 2GB or higher RAM is required. If your WordPress server doesn’t have this, you need to upgrade it.

• PHP: The PHP version needs to be more than 7.2.

• Hosting: In the case of shared hosting, sometimes you need to upgrade your hosting package or switch hosts to install Redis object caching.  If you are on managed wordpress hosting, it’s more likely that it will be available for free.

Steps:

1. After logging into your WordPress admin, click on Add New Plugin in the Plugin section. 

2. Search the Redis Object cache in the search box.

3. Click on the Install Now.

4. After installing click on the Activate section.

5. After activating this wordpress object cache, click on Enable Object Cache.

• Memcached:

Memcached is an open-source WordPress object caching system that stores strings and objects (resulting from database queries, API calls, or page rendering) in the server’s RAM.

It consists of four major components:

1. Client Software (collect the list of distributed Memcached servers)
2. Client-Based Hashing Algorithm (Selete the server based on the keys)
3. Server Software (Store that data (values and keys) in the hash table )
4. Server Algorithm (decide when to delete the old data)

Several caching plugins available in the wordpress ecosystem, that support Memcached such as Speed Optimizer, Object Cache 4 Everyone, and many more.

Is RabbitLoader Compatible with Redis Object Cache and Memcached Object Cache?

As RabbitLoader is designed to be compatible with various wordpress cache plugins, it will be compatible with WP object cache plugins as well such as Redis persistent object cache and Memcached object cache. 

Apart from the wordpress website, if you have a Laravel and PHP website, you can use RabbitLoader SDK because it is compatible with other caching plugins.

FAQ:

5 Web Caching Strategies to Boost Your Website’s PageSpeed Score

Web caching, the ultimate solution to supercharge your website’s pagespeed and enhance the user experience. But what is this web caching and what they actually do?

Technically, web caching is a temporary storage location for copies of static files or data. , let’s discuss web caching in detail and you will learn the powerful strategies to develop web caching that you can implement on your website to improve the pagespeed.

What is Web Caching?

Web caching is the concept of temporarily storing or caching the static resources of a website for reuse.

It makes a website faster by saving the heavier website’s resources. Example of what web cache stores are:

• Media files ( logo, images, videos)

• HTML files ( bits of code that create the content of a webpage)

• CSS stylesheets (a bit of code to add style to the webpage content)

• JavaScript files ( Scripting language to make the webpage more interactive)

Let’s understand with an example. You are visiting our website RabbitLoader.com. The first time the browser downloads and temporarily stores the RabbitLoader logo into the web cache. Every time you go to a different webpage on rabbitloader.com, the logo on the left top corner is loaded from the web cache. It will reduce the web page loading time.

Type of Caching on the Web?

Now you have a basic idea of web cache. Let’s discuss the different types of web cache. Web caching can be categorized into two parts: client-side and server-side. 

1.Client-Side Caching

happens when the browser saves the static resource files locally on the user’s computer. So that the files don’t have to be downloaded again.

2.Server-Side Caching

Indicates the web server temporarily stores the content of the webpage before it’s sent to the user’s browser. 

Here, we will explain the different types of cache such as browser cache (using client-side caching mechanism), proxy cache, and CDN cache which are well-known server-side caches.

• Browser Cache:

Browser cache is a client-side cache used to store images, Stylesheets, scripts, and other resources from the website. So,  when a user revisits the website, the cached content doesn’t need to be downloaded again. 

However, the browser cache has some drawbacks. It can introduce inconsistency. If the website’s content (like image or script) is changed then, the user will get a 304 Not Modified error for the stale cache content until they delete the cache. 

How to clear the web browser cache?

Let’s find out the steps to clear the browser cache in Google Chrome!

• Step 1: In Google Chrome go to the top right side and click on More (three dots). 
• Step 2:  Click on Clear browsing data or press Cntl+Shift+Del.

• Step 3: Select one time range, like All time or Last hour, and the type of information you want to remove from your browser.

• Step 4:  Click on Clear data.

• Proxy Cache:

A proxy cache is the most common type of server-side cache that lies between the user and the origin server. This cache is used for performance optimization, privacy, and security purposes.

When a user requests the content of the website, it can be fetched from the proxy server cache instead of its origin server. It will help to reduce the traffic and overload on the origin server.

Proxy servers also enhance security by filtering network traffic, scanning for viruses, encrypting data, and preventing malicious requests.

• CDN Cache:

A Content Delivery Network (CDN) is a group of proxy caching servers that are geographically distributed. It will reduce the real-world distance between the user and the original server. 

Content Delivery Network will help to improve the website pagespeed performance by reducing the latency. 

When a user requests content from a website through HTTP headers,  the HTTP request will arrive at the nearest PoP of the user.

• Cache Miss: happens If the requested content of the website is not present at the nearest server, The Content Delivery Network will retrieve that content from the origin server.

• Cache Hit: happens in a Content Delivery Network, If the requested content is present, then CDN can fulfill the request of the user by fetching the content through an HTTP response. 

What is the Cache Hit Ratio?

A cache hit ratio is used to measure the success of a Content Delivery Network (CDN) server’s cache system. The cache hit ratio is defined as the number of content requests a cache can deliver from the cache storage.

Let’s understand with an example. If a cache hit ratio is 75%, that means 75% of the requested content is served from the CDN cache, and the remaining 25% must be retrieved from the origin server.

The Impact of Web Caching 

Web caching has several significant impacts on the website’s performance. Let’s discuss a few reasons why a website needs web caching layers.

1. Web caching improves the website’s pagespeed performance:

By storing copies of the website’s static resources such as HTML files, CSS stylesheets, JavaScript files, and media files (images and videos) in the nearest edge location server, it will increase the website’s pagespeed by reducing latency. 

2. Web caching makes your website more secure:

Web caching allows you to access sensitive resources without exposing the resources to the server. You can control the web cache to restrict it based on an IP address and any other criteria. 

It will make this easier to audit and identify the hackers as well as bots.

3. Web caching reduces the server load:

When the cached resources are fetched from the web cache server rather than the origin server, it will reduce the load on the origin server. This also allows the server to handle more requests and improve the overall scalability.

So, web caching can be used as dependable and quick hosting to enhance the website’s performance.

Developing a Web Caching Strategy

Now, you have already covered the most important concepts of web caching. From here, we will discuss the strategies to develop a web cache.

There are certain strategies that you need to follow to develop web caching.

1.Identify cache resources:

First, you need to determine which resources should be cached if your website has some specific need. 

Usually, this may include static resources of website content such as HTML files, CSS stylesheets, JavaScript files, and media files ( images and videos), as well as dynamic content that is not changed frequently.

2.Understand cacheability:

You need to understand the cacheability of the resource files like how often they are changed or whether these resource files are sensitive to the user-specific data. Understanding cacheability is critical to setting a cache-control header.

3.Choose a caching mechanism:

After understanding the cacheability, you need to choose any caching mechanism like browser caching, proxy caching, or CDN caching. 

4.Set a cache-control header:

A cache control HTTP header carries the instructions for both requests and responses which control the whole caching process in the client-side cache as well as server-side cache.

Use an appropriate HTTP header such as Cache-Control to control the cache’s behaviours. By using this, you can set the max-age to specify how long the resources should be cached, no-cache which indicates the response must be stored in the cache but the response will validate with the backend or original server before reuse, and many more. 

5.Testing:

After configuring the caching you need to check in different browsers and devices to ensure consistent performance.

How RabbitLoader will help you in web caching?

The above strategies, which we’ve mentioned, are time-consuming and you need to do them manually, which requires a piece of coding knowledge. But why are you putting extra effort into this? 

There are many optimization plugins available such as RabbitLoader, WP Rocket, W3 total cache, and WP super cache to implement web caching in WordPress. You can also use RabbitLoader for your PHP, and Laravel custom website optimization. 

However, RabbitLoader is an all-in-one performance optimization plugin. No other optimization tools are required to enhance the website’s performance like other plugins when using RabbitLoader.

RabbitLoader will improve everything that’s needed for optimal performance. Not only that, RabbitLoader will enable premium CDN with 300+ POPs, and many more.

Conclusion

Here, you have a clear idea about web caching and how it helps you to improve your website’s performance and also learn the strategies to implement web caching on your website through as well as by using any plugin.

Now, you must implement web caching to improve the pagespeed of websites for a better user experience as well as higher SEO rankings.

Cache Hit Rate: How To Calculate It And 3 Powerful Techniques To Optimize It

The cache hit rate is one of the most important metrics in cache memory. It can be calculated by dividing the amount of cache hits by the total amount of cache requests that came from the browser. 

The cache hit rate is usually used to analyze cache efficiency. In other words, it determines the percentage of browser’s HTTP requests your cache can successfully serve. Increasing the cache hit rate is crucial for improving user experience.

But how to optimize this cache hit rate?

Let’s see the cache hit rate and how to calculate it. We will also explore how RabbitLoader can help you optimize your cache hit rate and enhance your user experience.

What Is Web Cache And How Does It Work?

Before discussing further the cache hit and cache miss rate, let’s first understand the web caching strategy. 

A web cache is a temporary memory for storing a website’s static content (stylesheets, scripts, and media files). It stores the content during a user’s first visit. Therefore, if the same visitor re-visits the page, it will render much faster. By implementing a web caching mechanism in your website, you can improve its loading time. 

Another advantage of using a web cache is that when a visitor opens your website, a browser such as Google Chrome sends an HTTP request to the origin server to request the content. Too many requests can overload the origin server, but you can mitigate this problem by using a web cache.

The resource which can be cached: 

Understand Cache Hit And Cache Miss With Examples

When a visitor requests content, the browser makes an HTTP request that arrives at the CDN cache. Two scenarios can occur.

• Cache Hit: If your Content Delivery Network fulfills the browser’s HTTP request by sending the content, this is known as a Cache Hit. 

• Cache Miss: if the requested content is not available in the edge server of the CDN cache, then it is not able to fulfill the browser request. This is known as a cache miss.

Let’s see the cache strategy with a real-time example. RabbitLoader publishes a blog on Google web fonts. You are the first visitor to this newly published blog. Therefore, when you request any content, the requested content will be sent from the backend server.

After loading the static resources (images, stylesheets) from the origin server it would be stored in your CDN cache. The next time another visitor from the same location visits the same blog, the static contents will be severed from the CDN cache. This is called a cache hit.

However, when a CDN is unable to deliver the requested content, it’s called a cache miss.

What Is The Cache Hit Rate And How To Calculate It?

The cache hit rate is used to measure how efficiently a CDN cache serves the website’s content from its cache memory. Let’s see how it can be calculated.

Cache hit rate formula= the number of cache hits/ Total cache requests (the summation of cache hits + cache misses)

In order to measure the cache hit ratio, multiply this cache hit rate by 100.

Cache hit ratio = (cache hit/ cache request (the summation of cache hit cache misses))* 100

When a cache hit ratio is more than 80 %, it is considered high. A result below 80 % indicates a lower cache hit ratio. 

Explaining The Cache Miss Rate And How To Calculate It?

The cache hit rate measures the efficiency of your cache memory. You can easily calculate the cache miss rate by dividing the amount of cache misses by the total HTTP cache request.

The formula of Cache miss rate = the amount of cache misses/ Total amount of cache requests (cache hits + cache misses)

By multiplying the cache miss rate by 100, you can easily measure your cache miss ratio. 

Cache miss ratio formula= (cache misses/ cache request (cache hits + cache misses))* 100.

Improve Cache Hit Ratio With RabbitLoader

In order to increase the cache hit rate manually, first, you need to set an efficient cache-control header, optimize the cache size, and finally set proper cache invalidation methods. 

However, RabbitLoader provides a non-coding solution. Its premium Content Delivery Network (CDN) distributes your website’s static content in the edge/ proxy server, which has 300+ PoPs. Also by the advanced cache invalidation technique, RabbitLoader is able to provide stable-free content.

Conclusion

As discussed earlier, optimizing the cache hit rate helps you to provide a seamless user experience. While the manual techniques for increasing the cache hit rate can be challenging for a non-technical person, RabbitLoader provides you with an easy solution.

Therefore, You must use RabbitLoader to increase this cache hit rate and enhance your web performance.