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Re: RFC: Pausing a query thread


Why not take a more daring approach - implement 'priorities' in
"SET PRIORITY = high|medium|low [or 1..9]  FOR processlist.ID=xx;"

I realize that this is not a trivial task, and obviously it requires so
much change in server architecture that it is not a solution for Marian

@Marian BTW (as you probably know the answer): what do hosting companies
offering 2.95 $-per-month 'web hotel' solutions do where hundreds or
thousands of users/customers share a MySQL server and one user repeatedly
executes idiotic queres from home-grown applications resulting in starving
of the server and thus effectively causing denial-of-service for other
users/customers? I was always surprised that they could manage it with
MySQL, actually!

-- Peter

On Mon, Jun 24, 2013 at 9:50 PM, Marian Marinov <mm@xxxxxxxx> wrote:

> Hi Roberto,
> MDEV-4623 is does exactly what I want in a different manner.
> I have a similar thing as MDEV-4427 written as MySQL plugin. Unfortunately
> this have one very big problem. It sometimes breaks tables. I have seen
> even InnoDB tables broken by this type of intervention :( I can't reproduce
> it very easy for InnoDB, but for MyISAM it should be pretty easy.
> Also killing query, even one that takes a lot of resources may result in a
> loss of data, which in turn says, that the service is bad.
> My opinion is, we should either accept a query and try to execute it while
> preventing resource starvation or we should deny it. It is very bad to
> accept it and then kill it in the middle of its work.
> This is a DataBase, it should either accept data or not.
> Marian
> On 06/24/2013 08:15 PM, Roberto Spadim wrote:
>> hi marian, could you see MDEV-4623 and MDEV-4427, and tell me if that
>> could help you?
>> MDEV-4623 <https://mariadb.atlassian.**net/browse/MDEV-4623<https://mariadb.atlassian.net/browse/MDEV-4623>>
>> - https://mariadb.atlassian.net/**browse/MDEV-4623<https://mariadb.atlassian.net/browse/MDEV-4623>-
>> lock/unlock connection
>> MDEV-4427 <https://mariadb.atlassian.**net/browse/MDEV-4427<https://mariadb.atlassian.net/browse/MDEV-4427>>
>> - https://mariadb.atlassian.net/**browse/MDEV-4427<https://mariadb.atlassian.net/browse/MDEV-4427>- twitter
>> like patch (this one is to kill a query, but after MDEV-4623 we could use
>> lock connection)
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