Mailing List Archive: Multiple wackamole/spread groups in same subnet

Multiple wackamole/spread groups in same subnet

Aug 21, 2002, 2:33 AM

Post #1 of 4 (2239 views)

Hi wackamole-users.

I'm currently using wackamole and RR DNS to distribute load between 3
machines for a client to great effect. Now our client has added five new
machines for a new project and they want the same solution as before.
The five machines are on the same subnet as the first 3 machines.

Is there anything that I should watch out for when setting up Spread or
wackamole for the new machines so as to not disturb the existing setup?

--
Hroi Sigurdsson hroi@ngdc.net
Netgroup Datacenter http://www.ngdc.net

Multiple wackamole/spread groups in same subnet [ In reply to ]

jesus at omniti

Aug 21, 2002, 7:12 AM

Post #2 of 4 (2143 views)

Permalink

Hroi Sigurdsson wrote:

> Hi wackamole-users.
>
> I'm currently using wackamole and RR DNS to distribute load between 3
> machines for a client to great effect. Now our client has added five
> new machines for a new project and they want the same solution as before.
> The five machines are on the same subnet as the first 3 machines.
>
> Is there anything that I should watch out for when setting up Spread
> or wackamole for the new machines so as to not disturb the existing
> setup?

Well, you will have to make a cut-over eventually. Before doing so, I
would bring up your new Spread ring running on a different port... That
way you can make sure that the ring works the way you expect. Then
switch all your wackamole's over to the new ring and new wackamole
configuration. You should be able to get away with mere seconds of
downtime.

--
Theo Schlossnagle
1024D/82844984/95FD 30F1 489E 4613 F22E 491A 7E88 364C 8284 4984
2047R/33131B65/71 F7 95 64 49 76 5D BA 3D 90 B9 9F BE 27 24 E7

Multiple wackamole/spread groups in same subnet [ In reply to ]

george at omniti

Aug 21, 2002, 7:15 AM

Post #3 of 4 (2149 views)

Permalink

Hroi Sigurdsson wrote:

> Hi wackamole-users.
>
> I'm currently using wackamole and RR DNS to distribute load between 3
> machines for a client to great effect. Now our client has added five
> new machines for a new project and they want the same solution as before.
> The five machines are on the same subnet as the first 3 machines.
>
> Is there anything that I should watch out for when setting up Spread
> or wackamole for the new machines so as to not disturb the existing
> setup?
>
Just using a separate group for the new wackamole config should be good.

8 hosts is good for spread, but somewhat contrary to what you might read
on the spread users list, if you go past 12 (especially if your machines
are moderatley loaded, you may want to run multiple rings to keep the
total count of machines per ring below that number. That's not a magic
number, btw, just where I've personally seen problems in the past.

Multiple wackamole/spread groups in same subnet [ In reply to ]

hroi at ngdc

Aug 21, 2002, 7:27 AM

Post #4 of 4 (2132 views)

Permalink

George Schlossnagle wrote:

>> Is there anything that I should watch out for when setting up Spread
>> or wackamole for the new machines so as to not disturb the existing
>> setup?
>>
> Just using a separate group for the new wackamole config should be good.

How do I set that? It seems that it is hardcoded in the source. Am I
right? (Version 1.2.0)

> 8 hosts is good for spread, but somewhat contrary to what you might read
> on the spread users list, if you go past 12 (especially if your machines
> are moderatley loaded, you may want to run multiple rings to keep the
> total count of machines per ring below that number. That's not a magic
> number, btw, just where I've personally seen problems in the past.

Thanks for your input. The three machines are quite loaded, serving 40
Mbits of mostly static content per machine. The runqueue load (load
average from "uptime") is around 25 most of the time.

I'll set up a separate ring on another port for the 5 new machines.

--
Hroi Sigurdsson hroi@ngdc.net
Netgroup Datacenter http://www.ngdc.net