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From:Walton Hoops Date:July 27 2009 5:56am
Subject:RE: Why doesn't mySQL stop a query when the browser tab is closedL
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Even if it did, it would be by convention only, there is no guarantee.  Not
only that, but it would likewise be dependent on the browser closing
normally, which is likewise no guarantee.  
The fact of the matter here however is that there is NO set of behavior that
would suit everyone.  I can think of several examples (modifying table
structure, inserting data, etc) where I would want query execution to
continue even after the client has gone away.
Lastly, and I'll test this later, is this strictly php behavior? I seem to
remember queries started with MySQL query browser running to completion even
after losing my connection (although I think these were all writes, not
reads). 

-----Original Message-----
From: Johnny Withers [mailto:johnny@stripped] 
Sent: Sunday, July 26, 2009 6:34 PM
To: Eric Bergen
Cc: Daevid Vincent; mysql@stripped
Subject: Re: Why doesn't mySQL stop a query when the browser tab is closedL

I'm not sure closing the browser window sends the RST packet back to
the server, if it does, that's great! However, if php is waiting on
mysql to return a result, it wouldn't notice this anyway until mysql
finished processing and returned control back to the script. I could
be completly off-base here, I have no way to test this.

On Saturday, July 25, 2009, Eric Bergen <eric.bergen@stripped> wrote:
> PHP will notice if the browser has disconnected when it tries to write
> data. If it detects the browser has disconnected it will stop script
> execution. You can control what php should do in the event of a
> disconnect with the ignore_user_abort() function. See the connection
> handling page for more details:
>
> http://us3.php.net/manual/en/features.connection-handling.php
>
> On Wed, Jun 3, 2009 at 2:54 PM, Johnny Withers<johnny@stripped>
wrote:
>> It just seems odd to me that PHP does a mysql_connect and gets a resource
>> ID. Then it uses that socket (or whatever it is) to do subsequent
queries.
>> Mysql has to know about it too in order for it to send back results to
the
>> same resource/handle/socket/whatever. So either PHP should do some
>> cleanup, which
>> I assume it does when the page goes away, otherwise PHP would leak memory
>> like a sieve all over the place as pages are closed/aborted.
>> PHP has no idea the browser left/aborted/died/etc. When you begin a
request
>> that PHP handles, it begins processing the script, which in turn begins
>> processing whatever instructions the script has. At no point in time is
it
>> aware if a "browser window" is waiting on its response, it simply spits
it
>> response back to the HTTP server which may or may not have a client
reading
>> the response to display to a user.
>>
>> PHP's clean up is when the script ends processing. You can see this by
>> creating a PHP script that takes ages to complete (no mysql involved,
maybe
>> just a loop and sleep statements that sends output to a text file) and
>> kicking it off by browsing to the page, then closing your browser and
>> tail'ing the output file, you will see it continuing to write to this
file
>> until the loop is complete.
>>
>> You can assume what you like about PHP, but that doesn't make it true.
>>
>> -johnny
>>
>>
>> On Wed, Jun 3, 2009 at 2:03 PM, Daevid Vincent <daevid@stripped> wrote:
>>
>>> We have a "NOC" that displays this sort of thing and shows myTop in six
>>> windows for DEV/TEST/PROD and Master/Slave for
>>> each.(http://www.daevid.com/content/examples/snippets.php scroll down to
>>> "Automatic Monitoring of remote servers" for a handy script)
>>>
>>> So we do monitor this and will kill long running queries by hand. I was
>>> hoping for something a little more automated however. It just seems odd
to
>>> me that PHP does a mysql_connect and gets a resource ID. Then it uses
that
>>> socket (or whatever it is) to do subsequent queries. Mysql has to know
>>> about
>>> it too in order for it to send back results to the same
>>> resource/handle/socket/whatever. So either PHP should do some cleanup,
>>> which
>>> I assume it does when the page goes away, otherwise PHP would leak
memory
>>> like a sieve all over the place as pages are closed/aborted, OR mySQL
>>> should
>>> get a signal that, "hey, your handle to return your data on just STB, so
>>> stop what you're doing please".
>>>
>>> On a related note then, is there a way to set a my.cnf setting so that
>>> queries that are going for longer than X seconds are re-niced or
something
>>> to not bog down the system? Ideally I'd assume you'd want each query to
>>> "peg
>>> the CPU" so that they're in and out quickly and the user can get on with
>>> their life. But these long running ones at some point X are then taking
>>> over
>>> the entire server with 135% CPU usage and killing the experience for any
>>> other user on the web site -- and for a duration too!
>>>
>>>
>>> > -----Original Message-----
>>> > From: Darryle Steplight [mailto:dsteplight@stripped]
>>> > Sent: Wednesday, June 03, 2009 8:41 AM
>>> > To: Jerry Schwartz
>>> > Cc: Jay Blanchard; Daevid Vincent; mysql@stripped
>>> > Subject: Re: Why doesn't mySQL stop a query when the browser
>>> > tab is closedL
>>> >
>>> > Hi Daevid,
>>> >
>>> > You can always stop the query by running
>>> >
>>> > SHOW PROCESSLIST;
>>> >
>>> > from the command line or your MySql Admin tool. The above command will
>>> > show you all of the queries that are currently running along with
>>> > their PID# and state. Find the query your want to stop, and run the
>>> > following command
>>> > KILL #; (where # is --
> Eric Bergen
> eric.bergen@stripped
> http://www.ebergen.net
>

-- 
-----------------------------
Johnny Withers
601.209.4985
johnny@stripped

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Thread
Why doesn't mySQL stop a query when the browser tab is closedLDaevid Vincent3 Jun
  • RE: Why doesn't mySQL stop a query when the browser tab is closedLJay Blanchard3 Jun
    • RE: Why doesn't mySQL stop a query when the browser tab is closedLJerry Schwartz3 Jun
      • Re: Why doesn't mySQL stop a query when the browser tab is closedLDarryle Steplight3 Jun
        • RE: Why doesn't mySQL stop a query when the browser tab is closedLDaevid Vincent3 Jun
          • RE: Why doesn't mySQL stop a query when the browser tab is closedLMartin Gainty3 Jun
          • Re: Why doesn't mySQL stop a query when the browser tab is closedLJohnny Withers3 Jun
            • Re: Why doesn't mySQL stop a query when the browser tab is closedLEric Bergen26 Jul
              • Re: Why doesn't mySQL stop a query when the browser tab is closedLJohnny Withers27 Jul
                • RE: Why doesn't mySQL stop a query when the browser tab is closedLWalton Hoops27 Jul