An user mentioned the problem here:
http://www.cubrid.org/660884
The reason of the issue is that the code calls get_db_parameter and this function is not supported. Check cubrid_log.txt for proxy_log messages and the test php file attached.
The shard1 database with shard user and shard123 password is the default one from this tutorial:
http://www.cubrid.org/manual/91/en/shard.html
Connection works fine from Java or nodejs.
We found the line of code that mentions that the operation is not supported (line 82 of shard_proxy_handler.c):
{code}
fn_proxy_client_not_supported, /* fn_get_db_parameter */
{code}