Memcached CLIENT_ERROR invalid compression

What is Memcached CLIENT_ERROR invalid compression

Understanding Memcached

Memcached is a high-performance, distributed memory object caching system, primarily used to speed up dynamic web applications by alleviating database load. It stores data in memory for quick retrieval, making it an essential tool for applications that require rapid access to data.

Identifying the Symptom: CLIENT_ERROR invalid compression

When using Memcached, you might encounter the error message: CLIENT_ERROR invalid compression. This error indicates that there is an issue with the compression settings being used in your Memcached configuration.

What You Observe

When this error occurs, you will notice that certain operations fail, and the error message is returned by the Memcached server. This can disrupt the normal functioning of your application, leading to potential performance degradation.

Explaining the Issue: Invalid Compression

The CLIENT_ERROR invalid compression error typically arises when the compression settings specified are not supported by Memcached. Memcached supports specific compression algorithms, and using unsupported settings will trigger this error.

Common Causes

Using an unsupported compression algorithm. Incorrect configuration of compression settings in the client library.

Steps to Fix the Issue

To resolve the CLIENT_ERROR invalid compression error, follow these steps:

Step 1: Verify Supported Compression Algorithms

Ensure that the compression algorithm you are using is supported by Memcached. Commonly supported algorithms include zlib and LZ4. Check the documentation of your Memcached client library to see which algorithms are supported. For example, the Memcached Wiki provides information on supported compression methods.

Step 2: Update Client Library Configuration

Review and update the configuration settings in your Memcached client library. Ensure that the compression settings align with the supported algorithms. For instance, if you are using a PHP client, you might need to adjust the settings in your php.ini or directly in your application code.

Step 3: Test the Configuration

After updating the configuration, test the changes by performing operations that previously triggered the error. Ensure that the error no longer occurs and that data is being compressed and decompressed correctly.

Additional Resources

For more information on configuring Memcached and troubleshooting common issues, consider visiting the following resources:

Official Memcached Website Memcached GitHub Wiki PHP Memcached Manual