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From:Thomas Seifert Date:August 14 2002 7:19pm
Subject:Re: Persisten Connections
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And I disagree with this view.

If you've got a server with 512 MB RAM and running the webserver and the
db-server on the same machine, 100 idling mysql-processes are a HUGE overhead.
At most if not every http-request requires a mysql-connection.

I did many benchmarks and I got a huge decrease of the server-load as I disallowed
persistent connections through the php.ini.

I am serving around 180K pageviews/day with this config and on the described server.

AFAIK it is MUCH more than 100K per mysql-process and a large process table is also
of no gain.

I may have to agree to your view but only if you have different servers for webserver
and database, but I never tested such a config.


On Wed, 14 Aug 2002 11:14:33 -0400 Tod Harter <tharter@stripped>

> On Wednesday 14 August 2002 09:54 am, Thomas Seifert wrote:
> I disagree entirely....
> Persistent connections have little or nothing to do with increasing load!
> Given that you mention you are using PHP I'll assume you have mod_php running 
> in Apache. Each Apache child process in this configuration will maintain ONE 
> open database handle, so 100k pageviews per day I would expect you might max 
> at like 30k in one hour, or around 10/second, so you might top out at roughly 
> 100 Apache child processes at any one time, thus 100 database connections.
> Each DB connection is not a huge overhead, but creating and destroying 10 
> database handles PER SECOND is a large overhead!!! Remember, every time mysql 
> creates a connection it has to do internal queries on the grant tables. I 
> don't know exactly what the overhead of that is going to be, but ANYTHING 
> that creates 10 queries per second is putting some strain on your database 
> server!
> One of the main goals of using Apache modules for scripting was to allow 
> persistent database connections. There is really NO reason to give up that 
> advantage. Remember, MySQL is multi-threaded, with one thread per connection, 
> so the resources for a database connection are on the order of under 100k of 
> memory per connection.
> > it will reduce the load for sure!
> > MySQL is very fast in opening and closing connections at least if the
> > database-server and webserver are on the same machine.
> > I don't know how it will perform on different machines.
> >
> >
> > Thomas
> >
> > On Wed, 14 Aug 2002 14:40:31 +0100
> >
> > "John Wards" <j.wards@stripped> wrote:
> > > I am running a website which generates around 100,000 pageviews a day and
> > > I am wondering if I stop using persistent conections to the MySQL
> > > database and use
> > > normal open and close conections this would reduce the load onto my
> > > server?
> > >
> > > Most conections are either made through my "main" file or the phorum
> > > message board system.
> > >
> > > Thanks in advance
> > > John Wards
> >
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Persisten ConnectionsJohn Wards14 Aug
  • Re: Persisten ConnectionsThomas Seifert14 Aug
    • Re: Persisten ConnectionsTod Harter14 Aug
  • Re: Persisten ConnectionsJocelyn Fournier14 Aug
  • Re: Persisten Connectionspeter.brawley14 Aug
  • Re: Persisten ConnectionsJocelyn Fournier14 Aug
  • Re: Persisten ConnectionsStreetWarz & SpeedWarz14 Aug
  • Re: Persisten ConnectionsJocelyn Fournier15 Aug
  • Re: Persisten ConnectionsGelu Gogancea15 Aug
  • Re: Persisten Connectionsmos16 Aug
  • Re: Persisten Connectionsmos17 Aug
Re: Persisten ConnectionsPaul DuBois14 Aug
Re: Persisten ConnectionsThomas Seifert14 Aug
RE: Persisten ConnectionsSteve Orr16 Aug
RE: Persisten ConnectionsSteve Orr16 Aug