Java Memcached Stats Items (Detailed Guide w/ Code Examples)

Use Case(s)

The 'stats items' command in Memcached is often used when you want to understand the status of your cache, specifically items stored within the cache. It provides information such as the number of items currently stored, total storage size for each slab, and other important statistics that can help optimize performance.

Code Examples

Here we are using the SpyMemcached client for Java.

1. Connecting to Memcached Server and Fetching Stats

import net.spy.memcached.MemcachedClient;

// ...

MemcachedClient client = new MemcachedClient(new InetSocketAddress("localhost", 11211));

// Fetch stats from Memcached server
Map<String, Map<String, String>> stats = client.getStats();

// Get item stats
Map<String, String> itemStats = stats.get("items");

// Print the stats
for (Map.Entry<String, String> entry : itemStats.entrySet()) {
    System.out.println(entry.getKey() + " = " + entry.getValue());
}

client.shutdown();

In this example, a connection to the Memcached server is established, then the getStats method is called which returns a map containing statistics about the server. Then it retrieves the "items" statistics and prints them out.

Best Practices

• It's usually best to not run 'stats items' too frequently as it could consume additional resources. Instead, use it mainly for debugging and occasional monitoring.
• Always remember to close the memcached client connection after use to release the resources.

Common Mistakes

• Forgetting to handle exceptions. Network issues or an unavailable server should be properly handled to prevent your application from crashing.
• Not shutting down the Memcached client which may lead to resource leaks.

FAQs

1. Why are my item stats empty?
   If your Memcached server is recently started, or if it hasn't stored any items yet, item stats may be empty.

2. Can I use 'stats items' for real-time monitoring?
   While possible, it's not recommended due to the additional load it could put on the server. Use sparingly and consider other monitoring solutions for more frequent updates.