Chris
Thanks for the link.
Increasing number of connections is one of the options by which we will get bigger heap memory pool at the reboot of ASE server. And apart from increasing per process memory I may just do this as temporary measure. (more details below)
Anyway in our case it turned out to be a bug in ASE 16 SP02
It was not there in 15.5 or 15.7.
Underlying cause is a login trigger we use to set up two variables with use of set app_context.
Use of set app_context fragments the heap memory pool severely. And that leads to error 712 finally.
Most likely we will request a one off for this.
Cheers.
Avinash