Mailing List Archive

Re: Does someone really use LVS as a HTTP,FTP or SMTP server?
Hi Huatao,

I hope you don't mind if I post this to the lvs mailinglist.

> So if i have dynamic webserver content, the realservers will share one
> database or they each have one and keep them snychro? If those
> requests are mostly database related, i guess the workload will not be
> balanced very well if there is only one database. And if those
> realsevers each have a database, let's say MySQL, is it possible to
> keep them synchro?

I can't give you the correct answer here since I don't know enough about
databases. But there are a lot of people here on the list that know this
and it has also been addressed quite some times in the list. That's why
I forward this mail to the list.

> Sorry, i think i did not make myself very clear in last letter, but
> your answer is very helpful, i can learn a lot from it as well :-)

Good to know ;) I also learn a lot in this mailing list.

> What i really wanted to say is how to verify those scheduling
> algorithms like rr,wrr,lc,wlc, using browser? But cache is a big
> problem when making verifications.

Oups, you lost me here. Could you elaborate a little bit more on the
first question? Do you want to know what scheduler is running by
connecting to the VIP? ???

> It's so kind of you!
> Your answers are very helpful.
> Thank you very much!

I'm glad having helped someone. Best regards,
Roberto Nibali, ratz

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mailto: `echo NrOatSz@tPacA.cMh | sed 's/[NOSPAM]//g'`
Re[2]: Does someone really use LVS as a HTTP,FTP or SMTP server? [ In reply to ]
Hello ratz,

Tuesday, November 21, 2000, 7:29:59 PM, you wrote:

r> I hope you don't mind if I post this to the lvs mailinglist.

Of course not :-)

>> What i really wanted to say is how to verify those scheduling
>> algorithms like rr,wrr,lc,wlc, using browser? But cache is a big
>> problem when making verifications.

r> Oups, you lost me here. Could you elaborate a little bit more on the
r> first question? Do you want to know what scheduler is running by
r> connecting to the VIP? ???

In fact, i want to know how to verify those scheduling algorithms
like rr,wrr,lc,wlc each is doing it's own work. For example,
if i use Netscape Navigator 4.7 to connect to the VIP, and keep
reloading, i should be able be see the index.html in DocumentRoot
of the webserver on each different realserver alternating accroding to the
scheduling algorithm(of course the index.htmls are different :-) ),
but it's not working very well , due to the cache of Netscape
Navigator, i think. Lynx is better? I'll try it.

Thank you, ratz.

--
Best regards,
huatao mailto:thua@sei.xjtu.edu.cn
Re: Does someone really use LVS as a HTTP,FTP or SMTP server? [ In reply to ]
Hi Huatao,

> r> Oups, you lost me here. Could you elaborate a little bit more on the
> r> first question? Do you want to know what scheduler is running by
> r> connecting to the VIP? ???
>
> In fact, i want to know how to verify those scheduling algorithms
> like rr,wrr,lc,wlc each is doing it's own work. For example,

Aha, now I understand, this is rather simple.

> if i use Netscape Navigator 4.7 to connect to the VIP, and keep
> reloading, i should be able be see the index.html in DocumentRoot
> of the webserver on each different realserver alternating accroding to the
> scheduling algorithm(of course the index.htmls are different :-) ),
> but it's not working very well , due to the cache of Netscape
> Navigator, i think. Lynx is better? I'll try it.

Do a SHIFT+[click on reload] and this should work. At least it works over
here. For some (for me) unknown reasons if you just click on reload, some-
times the cache comes into play. So press shift and then click and it will
work.
But as you already mentioned, using lynx is of course the better variant
to test it ;) Just do a:
while true; do lynx -nolog -nopause -noredir -reload -mime_header http://VIP/;
sleep 1; done
and watch your different static pages fly by. It's a good proof-of-concept.

HTH,
ratz

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mailto: `echo NrOatSz@tPacA.cMh | sed 's/[NOSPAM]//g'`
Re: Does someone really use LVS as a HTTP,FTP or SMTP server? [ In reply to ]
ratz wrote:

> Do a SHIFT+[click on reload] and this should work. At least it works over
> here. For some (for me) unknown reasons if you just click on reload, some-
> times the cache comes into play. So press shift and then click and it will
> work.

I've been in situations where shift reloading doesn't rotate through
the real-servers. I assumed it was due to HTTP persistance and I've
since used telnet to port 80 to check that all real-servers were on line.
(I expect lynx will do the same thing).

I have apache 1.3.x running right now and I notice that with KeepAliveTimeout of
15 secs
that rapid shift reloads rotates through all websites.
This happens with static and SSI pages.
Shift reloads at greater intervals (>15 secs)
sometimes get the same pages and sometimes rotates.

I can't find anything helpful on the netscape or apache websites
beyond all current browsers supporing KeepAlives (persistance connection)

Anyone know what's going on?

(I'm off for thanksgiving for a 3days in a minute or 2).

Joe

--
Joseph Mack PhD, Senior Systems Engineer, Lockheed Martin
contractor to the National Environmental Supercomputer Center,
mailto:mack.joseph@epa.gov ph# 919-541-0007, RTP, NC, USA