MySQL / MariaDB change feeds Is there a way to get a notification when a row in a table is created or updated? Much like RethinkDB's change feeds. 

Anything would work really - a message on a WS channel, or a HTTP request with the data that was created/updated...

Cannot use trigger to copy to temp table and poll, this is for a real time currency fx feed.

I've also been looking at reading from binlogs but it's too complicated, adds overhead and multiple possible points of failure.

Later edit: also tried lib_mysqludf_sys to sys_exec() a PHP script that connects to the WS server to send the update, it takes between .25 and .50 seconds, which is very very slow considering the single table I am interested in gets updated several thousand times per minute.
MySQL and MariaDB do not have any way for a TRIGGER to invoke anything outside of the MySQL/MariaDB server.  (To do so would be to create a security problem.)

Well, you could write a UDF that could do anything, and compile a special version of the server, etc.

You are probably better off polling, as you mentioned.  If there are thousands of updates per minute, the polling could "optimize" the fetch via GROUP BY and other techniques.