Very different behaviour executing stored procedures between 5.5 and 5.7

[Daniel Bradley]

Hi,

We recently upgraded from Ubuntu 14 LTS to 16 LTS, and in so doing, from MySQL 5.5 to MySQL 5.7.

We are getting very different behaviour regarding the execution of stored procedures between the two different systems.
Firstly, MySQL 5.7 seems to return a result set from a stored procedure as soon as a select statement is encountered and doesn't wait until the stored procedure completes.
Secondly, performance is much much slower. Stored procedures that used to execute almost instantaneously are now taking many seconds to execute. Tests were performed in isolated VMs so the only real difference was MySQL (and Apache/PHP).

Is there any documentation that describes any differences in how stored procedures are implemented in MySQL 5.7 compared to 5.5?

Does anybody have any experience with this that might help me deal with the situation?

At the moment, I'm considering downgrading back to MySQL 5.5.

Regards,
Daniel Bradley