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From:Johnny Withers Date:July 27 2009 12:33am
Subject:Re: Why doesn't mySQL stop a query when the browser tab is closedL
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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
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