According to MySQL 5.1's manual, section 18.104.22.168 KILL Syntax, when you
kill a connection, a thread-specific kill flag is set for the thread. The flag will then be checked from time to time, even during some long-running queries, so that it can interrupt the query.
Is there a way to instruct a thread not to check the kill flag while inside some kind of delimited critical section?
What I'm looking for is something like:
BEGIN IGNORE_KILLS; -- if this thread is killed here, it will simply ignore it END IGNORE_KILLS; -- here, the thread would be able to tell if someone tried to kill it previously
Assuming that it does not exist, or that someone could offer me a better solution to my problem, let me explain why would I want it.
I have an application that must react to lines that are inserted in a table, and this must be scalable. According to MySQL expert Baron Schwartz, one should not keep polling the database, and he proposes, as an alternative, to use
The problem is that after the connection waiting on
select sleep(...) is notified (by being killed) that it has work to do, I'd like to guarantee that, during its work (what I called critical section above), it won't stop doing what it should do even in the case that the killer thread goes crazy and kills it again.