maria-developers team mailing list archive

[Roberto Spadim <roberto@xxxxxxxxxxxxx>]

Hi Guys!
Some mariadb's user comments :)


2013/9/12 Sergey Vojtovich <svoj@xxxxxxxxxxx>

> Hi Sergei,
>
> thanks for your comments, answers inline.
>
> On Thu, Sep 12, 2013 at 04:27:57PM +0200, Sergei Golubchik wrote:
> > Hi.
> >
> > Good work.
> > I only have one small comment about the code, see below.
> > And one about the syntax.
> >
> > > === modified file 'sql/sql_parse.cc'
> > > --- sql/sql_parse.cc        2013-08-14 08:48:50 +0000
> > > +++ sql/sql_parse.cc        2013-09-11 12:29:32 +0000
> > > @@ -7139,24 +7139,60 @@ THD *find_thread_by_id(ulong id)
> > >
> > >
> > >  /**
> > > -  kill on thread.
> > > +  Find a thread by query id and return it, locking it LOCK_thd_data
> > > +
> > > +  @param id  Identifier of the query we're looking for
> > > +
> > > +  @return NULL    - not found
> > > +          pointer - thread found, and its LOCK_thd_data is locked.
> > > +*/
> > > +
> > > +static THD *find_thread_by_query_id(longlong id)
> >
> > why didn't you reuse find_thread_by_id()?
> > this function is almost identical to it.
>
That was the patch that i sent on MDEV, just a raw idea, but worked, maybe
a copy and paste hehe =)



> For no good reason, I'll fix it.
>

> >
> > > +{
> > > +  THD *tmp;
> > > +  mysql_mutex_lock(&LOCK_thread_count); // For unlink from list
> > > +  I_List_iterator<THD> it(threads);
> > > +  while ((tmp=it++))
> > > +  {
> > > +    if (tmp->get_command() == COM_DAEMON)
> > > +      continue;
> > > +    if (tmp->query_id == id)
>
there was a warning in gcc about unsigned and signed when i put the patch
in jira, but i didn't removed
maybe "if ((longlong) (tmp->query_id)==id)" could remove the warning, but i
don't know if it's ok



> > > +    {
> > > +      mysql_mutex_lock(&tmp->LOCK_thd_data);    // Lock from delete
> > > +      break;
> > > +    }
> > > +  }
> > > +  mysql_mutex_unlock(&LOCK_thread_count);
> > > +  return tmp;
> > > +}
> > > +
> > > +
> > > === modified file 'sql/sql_yacc.yy'
> > > --- sql/sql_yacc.yy 2013-08-13 11:35:36 +0000
> > > +++ sql/sql_yacc.yy 2013-09-11 12:29:32 +0000
> > > @@ -12890,6 +12891,11 @@ kill_expr:
> > >              Lex->users_list.push_back($2);
> > >              Lex->kill_type= KILL_TYPE_USER;
> > >            }
> > > +        | ID_SYM expr
> > > +          {
> > > +            Lex->value_list.push_front($2);
> > > +            Lex->kill_type= KILL_TYPE_QUERY;
> > > +          }
> >
> > So, you implemented KILL [ CONNECTION | QUERY ] [ ID ] expr
> > It allows, in particular
> >
> >    KILL CONNECTION ID 10
>
I like the QUERY_ID with underscore to know that we are talking about the
query_id, not the thread_id
example:
KILL CONNECTION QUERY_ID 99999
KILL QUERY QUERY_ID 99999



> >
> > which looks strange, why would that mean that 10 is a query id?
> >
> > I originally suggested KILL [ CONNECTION | QUERY [ ID ] ] expr
> > to allow only
> >
> >    KILL CONNECTION expr
> >    KILL QUERY expr
> >    KILL QUERY ID expr
> >
> > because in this case it's quite clear "QUERY ID" and because
> > I thought it's a bit strange to kill a connection by query_id.
>
>
> > If you want to allow that (as I saw in the comments, Roberto didn't
> > thought it's strange to kill a connection by query id), may be you'd
> > better use
>
For me, it's ok to kill connection or query using the query id or the
thread id, both are nice solutions
the query_id can change while we read the processlist and send the kill
command, while the thread_id many times don't
i want kill using the query id as parameter not the thread id, if the query
isn't what i want, mariadb will send an error or a warning, that's what i
expect

i'm new to source code of mariadb, it's difficult for me to change bison
files, i tested but was very confusing to me now (maybe in future i could
change it easier)
i think a nice nice syntax could be:
KILL [CONNECTION | CONNECTION QUERY ID | QUERY | QUERY ID ] exp
just an idea I think that QUERY_ID is easier to implement in bison than
QUERY ID, but i'm a begginner :P



> >    KILL [ CONNECTION | QUERY ] [ QUERY_ID ] expr
> > ?
> Same here. I was a bit scared by amount of affected test cases, so decided
> to submit "early" patch.
>
wow! a lot of test changes!


i didn't found a kill test with many ids, for example:
KILL QUERY ID 1,2,3,4,5
in my patch it didn't worked :P and i don't know how to allow it
i think the "KILL 1,2,3,4,5" is allowed for KILL command based on threads,
arent? could be nice the same syntax for kill query_id :) since it's the
"same" KILL command, but using different "WHERE" parts


another question :) maybe in futures MDEV could be nice something like:
KILL QUERY_ID IN (1,2,3,4,5) or
KILL QUERY_ID IN (SELECT QUERY_ID FROM information_schema.PROCESSLIST WHERE
..... )
KILL THREAD_ID IN (1,2,3,4,5) or
KILL THREAD_ID IN (SELECT ID FROM information_schema.PROCESSLIST WHERE
..... )
KILL CONNECTION QUERY_ID IN (1,2,3,4,5) or
KILL CONNECTION QUERY_ID IN (SELECT QUERY_ID FROM
information_schema.PROCESSLIST WHERE ..... )
KILL CONNECTION THREAD_ID IN (1,2,3,4,5) or
KILL CONNECTION THREAD_ID IN (SELECT ID FROM information_schema.PROCESSLIST
WHERE ..... )

it's another mdev, but what you think about it?


> Thanks,
> Sergey
>
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thanks guys! you are the best!

-- 
Roberto Spadim