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Johan,
"In a dedicated database setup we have big problems running over 500
connections to MySQL."
You shouldn't have a problem with this... MySQL can handle well over that
given a good amount of ram and processing power.
Let me tell you about our setup and hopefully it will help you make a better
decision.
Two LVS directors mon+heartbeat+lvs
6 Web Servers (512mb ram + 733 Mhz)
2 DB Servers (1 GB ram + 866) in Hot Replication (active/active)
We serve aprox 280 million page views per month off this setup and MySQL
does avg 1,200 quieries per second.
About serving static images, there is a web server, khttpd, that can be
compiled into the kernel to serve static pages. Very efficient. Just have
all your images hosted at images.yourdomain.com or use a different port.
"One scenario could be that the load balancer would look at the requests and
direct all /images/* to the static virtual server. I know that some
loadbalancers can do that, how about LVS?"
I don't know if LVS can do this but if it can it would require LVS to read
HTTP request hearders and really slow things down. IMHO no realy point.
Regards,
Rajiv Khaneja
-----Original Message-----
From: lvs-users-admin@xxxxxxxxxxxxxxxxxxxxxx
[mailto:lvs-users-admin@xxxxxxxxxxxxxxxxxxxxxx]On Behalf Of Johan
Isacsson
Sent: February 26, 2001 12:36 AM
To: lvs-users@xxxxxxxxxxxxxxxxxxxxxx
Subject: SV: Introduction and LVS/DR 2.4 realserver questions
Hello Rajiv,
We have actually considered both options for quite some time and for now
httpd+mysql on same host seems to be the best configuration. I'll explain
why:
Each mahine can take up to about 200 http connections with 1 Gb RAM (all
realservers have 1 Gb RAM). Since we use PHP the http processes are at least
5 Mb in size, so we have big memory problems if we go any further than that.
At that load the local MySQLd runs fine having about 200 connections.
In a dedicated database setup we have big problems running over 500
connections to MySQL. So instead of having, for example, 2 webservers
sharing 1 database machine and still just get to handle 400 connections we
choose to have 2 web+db machines that can also take 400 connections.
That saves us the cost of 1 db mahine per 2 web servers. In total we save 8
machines, and that's http 1600 connections :)
If anyone have comments on this i'd love to hear them.
One thing we've been thinking about is to serve static images from separate
webservers running boa or some other small and efficent webserver. The
problem with it is that it would make life complicated for the designers and
webmasters unless there was a way of doing it behind the scenes.
One scenario could be that the load balancer would look at the requests and
direct all /images/* to the static virtual server. I know that some
loadbalancers can do that, how about LVS?
Well, thanks for your comments :)
Regards,
Johan Isacsson
MGON
> -----Ursprungligt meddelande-----
> Från: lvs-users-admin@xxxxxxxxxxxxxxxxxxxxxx
> [mailto:lvs-users-admin@xxxxxxxxxxxxxxxxxxxxxx]För Rajiv Khaneja
> Skickat: den 26 februari 2001 09:05
> Till: lvs-users@xxxxxxxxxxxxxxxxxxxxxx
> Ämne: RE: Introduction and LVS/DR 2.4 realserver questions
>
>
> Hello,
>
> Greetings, I am new to this list as well and would like to offer some
> friendly advice. Get your MySQL databases on to some dedicated servers.
> Why run a RDBMS + Webserver on the same machine? You should see some big
> improvements...
>
> Regards,
> Rajiv Khaneja
>
> -----Original Message-----
> From: lvs-users-admin@xxxxxxxxxxxxxxxxxxxxxx
> [mailto:lvs-users-admin@xxxxxxxxxxxxxxxxxxxxxx]On Behalf Of Johan
> Isacsson
> Sent: February 25, 2001 10:47 PM
> To: Lvs-Users
> Subject: Introduction and LVS/DR 2.4 realserver questions
>
>
> Hello,
>
> I'm new to this list so here comes a little introduction.
> My name is Johan Isacsson and i'm the CTO of MGON International
> AB, based in
> Sweden.
> MGON creates and maintains websites about computer games, traffic is about
> 25 million impressions/month.
> Almost all pages are dynamic, so we need to distribute the load
> over several
> servers. We're running Linux 2.2 with Apache+PHP and MySQL on all
> realservers, about 16 in total.
> We use custom/scp script for file mirroring but are looking for
> better ways
> of doing that (any suggestions are welcome).
> Currently we use LVS/DR to distribute the load and it works very well for
> us.
> Before that we used IBM Network Dispatcher which i think worked
> the same way
> as LVS/DR do, but it costs lots of money! :P
> Well, enough about me, on to the questions!
>
> 1. Is the redirect approach working (well) on 2.4, and if so, are
> there any
> drawbacks using that method compared to the hidden arp method in 2.2?
> 2. Is it a very bad idea to just have 1 NIC on the LVS machine to receive
> and forward the requests?
>
> It's a DR setup.
>
> We have another server location with a 4Mbit connection that we don't use
> much. We have some servers there serving static files, but i'd
> like to load
> balance them between that location and our main location. Like this:
>
> Location 1 (Max 4Mbit)
> Static file servers
> FS1
> FS2
>
> Location 2
> Static file servers
> FS3
> FS4
> Virtual server
> VFS1 (FS1,FS2,FS3,FS4 LVS/TUN)
>
> I'd like to use as much as possible of the bandwidth in location 1 (up to
> 4Mbit) and after that start using the fileservers at location 2. The
> bandwith usage can be taken from the router at location 1 using snmp.
> If anyone have suggestions about how to set up scheduling for
> this i'd love
> to hear them :)
>
> Thanks for your time,
>
> Johan Isacsson
> MGON
>
>
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>
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> Send requests to lvs-users-request@xxxxxxxxxxxxxxxxxxxxxx
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