Distributed caching is a technique that improves the performance and scalability of web applications by storing frequently accessed data in a distributed cache. This reduces the load on the database and improves response times significantly.

In this blog post, we will explore how to implement distributed caching with GlassFish, a popular Java application server, and the Java Caching System (JCS), a powerful caching library.

What is distributed caching?

Distributed caching involves setting up a cache that is shared across multiple servers, enabling them to access and store data in a distributed manner. This allows for faster data retrieval and eliminates the need to hit the database repeatedly for the same data.

Setting up GlassFish and JCS

To get started, you will need to have GlassFish installed on your system, as well as the JCS library added to your project’s dependencies. You can add JCS as a Maven dependency in your pom.xml file:

<dependency>
    <groupId>org.apache.jcs</groupId>
    <artifactId>jcs-core</artifactId>
    <version>2.3</version>
</dependency>

Configuring GlassFish for distributed caching

GlassFish provides built-in support for distributed caching through its caching service API. To configure GlassFish to use JCS as the caching provider, you need to make some modifications to the domain.xml file of your GlassFish installation.

Open the domain.xml file and add the following lines under the <java-config> section:

<java-config>
    ...
    <caching-service>
        <cache-provider>jcs</cache-provider>
    </caching-service>
    ...
</java-config>

Save the changes and restart GlassFish for the configuration to take effect.

Using JCS for distributed caching

With GlassFish configured, you can now start using JCS for distributed caching in your Java application. JCS provides a simple and intuitive API for storing, retrieving, and managing cached data.

To store data in the cache, you can use the following code snippet:

import org.apache.jcs.JCS;
import org.apache.jcs.access.exception.CacheException;

...

try {
    JCS cache = JCS.getInstance("myCache");
    cache.put("key", "value");
} catch (CacheException e) {
    // Handle cache exception
}

To retrieve data from the cache, you can use the following code snippet:

import org.apache.jcs.JCS;
import org.apache.jcs.access.exception.CacheException;

...

try {
    JCS cache = JCS.getInstance("myCache");
    String value = (String) cache.get("key");
} catch (CacheException e) {
    // Handle cache exception
}

Conclusion

Implementing distributed caching with GlassFish and JCS can greatly improve the performance and scalability of your web applications. By reducing the load on the database and caching frequently accessed data, you can achieve faster response times and better overall user experience.

To get started, make sure you have GlassFish and JCS properly configured, and then use the JCS API to store and retrieve data from the distributed cache.

#distributedcaching #GlassFish #JCS