The error message "unable to load dynamic library 'redis.so'" indicates that the Redis server is unable to load the necessary Redis extension library, which is required for Redis to work correctly. The reason behind this error could be various, but the most common one is that the Redis extension library is not installed or configured correctly on the system.
Sometimes, the Redis extension library may also be missing or corrupted due to an incomplete installation process, a version mismatch between the Redis server and the extension library, or a conflict with other extensions. Additionally, the error can also happen if the Redis configuration file is pointing to a non-existent or incorrect location of the Redis extension library.
To resolve "unable to load dynamic library 'redis.so'" error in Redis, there are several solutions depending on the root cause of the issue. First, you need to confirm that the Redis extension library is installed and available on your system. You can check this by running the command php -m | grep redis. If it returns nothing, then it means that the Redis extension library is missing, and you need to install it using the package manager or manually.
If the Redis extension library is already installed, then make sure that it is configured correctly in the PHP configuration file. You can locate the PHP configuration file by running the command php --ini. Edit the configuration file and ensure that the extension=redis.so line is uncommented and pointing to the correct location of the Redis extension library.
In case the Redis extension library is corrupted or incompatible, try reinstalling it from the official source or updating it to a compatible version. If none of the above solutions work, you can consider disabling conflicting extensions or contacting Redis support for further assistance.