How to Fix Memcached Returning Null for Strings Set in Python and Accessed in Java?

Why is Memcached returning null when a string is set using Python and retrieved using Java?

# Python Code to set value in Memcached
import memcache

client = memcache.Client(['127.0.0.1:11211'], debug=1)
client.set('some_key', 'Hello from Python')

When using Memcached to store a string set in one programming language, such as Python, and then retrieving it in another, like Java, there can be discrepancies that result in null values. This usually occurs due to differences in serialization and connection details between the two languages.

// Java Code to get value from Memcached
import net.rubyeye.xmemcached.XMemcachedClient;
import net.rubyeye.xmemcached.exception.XMemcachedException;

XMemcachedClient client = new XMemcachedClient("127.0.0.1", 11211);
String value = client.get("some_key");
System.out.println("Value from Memcached: " + value);

Causes

• Incompatible serialization formats used by Python and Java.
• Different key casing or character encoding issues.
• Network issues that may prevent Java from accessing the Memcached instance.

Solutions

• Ensure that both Python and Java are using compatible serialization formats, such as JSON.
• Verify that the keys used for setting and retrieving values are identical in casing and formatting.
• Check the network configuration to ensure Java can reach the Memcached server.

Mistake: Using different casing for keys in Python and Java.

Solution: Always use consistent casing (e.g., all lowercase) for keys in both languages.

Mistake: Not connecting to the correct Memcached instance or port.

Solution: Ensure that the Memcached server address and port are correctly configured in both applications.