I use both. They both work well, but:
1. php has security risks involved as you need to supply connection details, passwords etc over the air. It is also a bit slower than jRDC2
2. jRDC2 works very well and is fast, but, has some tricks up it's sleeve to get the ultimate out of it. Not difficult to setup or use - you just have to know where what and how.
My setup reads only MySQL at this time and is based on a hosted Windows Server, running a Xeon setup, as listed below
On this server I have a MySQL server, MQTT server, CLOUD KVS server and jRDC2 server running side by side without a problem. I have never experienced a slow down or hickup with it. I have had a really hard time getting this machine over 6% usage at any one time.
My conclusion:
You will not go wrong with jRDC2 - choose your drivers correctly, setup your config file properly, setup your MySQL correctly and make use of Procedures where you can with parameters and it should run faultlessly forever and a day. Mine has been running continuously for 310 days and 7.5 hours now !!
Hope this helps.
Enjoy !!
