The error message 'memcached cannot assign requested address' usually occurs when Memcached is unable to bind to the specified IP address or port number. This could happen if the IP address or port number is already in use by another process, or if it is invalid or reserved for another purpose.
Another possible cause of this error is that Memcached is trying to allocate more memory than is available on the system. This can happen if the -m parameter is set too high or if there are other processes consuming a large amount of system memory.
To resolve the 'memcached cannot assign requested address' error, you can try the following solutions:
Check if the specified IP address and port number are valid and not in use by any other processes on the system. If they are already in use, you may need to change them to a different value.
Check if the system has enough free memory to accommodate the memory allocation specified with the -m parameter. If not, reduce the memory allocation or shut down other memory-intensive processes running on the system.
Increase the limits for the maximum number of open files and sockets on the system. You can do this by modifying the ulimit settings for the user running Memcached.
Ensure that the firewall settings allow incoming connections to the specified IP address and port number. If the firewall blocks these connections, Memcached will be unable to bind to the address and port.
By taking these steps, you should be able to resolve the 'memcached cannot assign requested address' error and get Memcached up and running again.