Re: FN-FORUM: Dedicated linux hosting query

date posted 21st August 2003 15:10

Bill Martin [EMAIL REMOVED] wrote:

> I have clarified with them that when they say 100 concurrent connections
> they don't just mean on the database the are talking overall.

Sounds to me like they are spinning you a line, ask them how they measure
this and ask them to provide some evidence so you can see (for your own
performance tuning of course ;).

You don't have concurrent connections unless you're talking about the
database. When you browse a web site then each object (for which I am
talking about an html file, or a gif, or a jpg) is one TCP connection
that is opened, data transfered, and then closed.

I wouldn't say you can class them as concurrent because they never stay
open that long, only long enough to transfer the data for the particular
object.

> Does anyone have any idea about how to monitor overall connections?

For MySQL there is a tool called (I think) MyTOP, which shows you MySQL
connection/query usage.

> I have a dev server here with the website on and want to see how many
> concurrent connections normal browsing by one user accounts for, to see
> if I can optimise the site in some way, to reduce connections.

I'd say it's impossible to measure, well I suppose you could find some
way of measuring number of port 80 TCP connections over a time period,
but it's a pretty meaningless measure of anything IMO.

> I thought that if one PHP page opens a mysql database and does 3/4/5..
> queries, this is one connection not 3/4/5 etc. So optimisations of
> individual scripts is not going to bring to connections down unless I can
> remove the connection to mysql altogether on some pages. Is this right?

My understanding/observation is that each fork()'ed Apache process will open
a separate d/b connection for each d/b user that talks to the d/b.

-Paul-

--
Paul Civati www.xensia.net
Xensia, London UK - Quality UK Hosting Services