Re: Proposed change to make cancellations safe

Simon Riggs <simon(at)2ndquadrant(dot)com> writes:
> On 24 April 2016 at 17:54, Shay Rojansky <roji(at)roji(dot)org> wrote:
>> I definitely agree that simply tracking message sequence numbers on both
>> sides is better. It's also a powerful feature to be able to cancel all
>> messages "up to N" - I'm thinking of a scenario where, for example, many
>> simple queries are sent and the whole process needs to be cancelled.

> For security, I think any non-matching cancellation would be ignored so
> that only someone with proper context could issue the cancel.

Well, we already have a random cancel key in the requests. As a separate
matter for a protocol change, it might be nice to consider widening the
cancel key to make it harder to brute-force; but I disagree that the
current proposal has anything whatever to do with security.

regards, tom lane