High availability tips & ideas

[George Daflidis-Kotsis]

On Tue, Feb 18, 2003 at 01:35:34PM +0200, Σταμάτης Κεκές wrote:

> George Daflidis-Kotsis wrote:
> 
> >On Tue, Feb 18, 2003 at 11:39:06AM +0200, Σταμάτης Κεκές wrote:
> >
> >>Geia xara se olous kai oles sti lista!
> >>Edo kai kamposo kairo thelo na stiso ena cluster me 2 web servers opou 
> >>tha exoun kai ftp epano tous gia to upload.
> >>esto loipon oti o enas exei tin IP 10.0.0.2/24 kai o allos tin 
> >>10.0.0.3/24 kai i floating IP einai i 10.0.0.4/24.
> >>
> >
> >Giati enw les IP perigrafeis ena /24 network?
> >
> Giati apla ithela na doso kai netmask. Gia syntomia loipon anti tou 
> 255.255.255.0 evala to /24 ;-)

Ah, ok. Parablepsh dikia mou.

> >>Mexri stigmis xrisimopoiontas to heartbeat katafera na apo tin proti 
> >>stigmi na exo mai floating IP kai ola ta requests http kai ftp na 
> >>ftanoun ston server kai na douleyei mia xara.
> >>Otan omos erixna ton "active" server pethainan kai ta connections pou 
> >>eixe kai tin floating IP tin epairne o allos.
> >>To erotima mou einai to eksis:
> >>Ksereis kaneis i exei dei kaneis kapoio tropo na ginetai takeover 
> >>transparently diladi xoris na xathoun ta ftp connections ?
> >>Eyxaristo prokatavolika osous kai oses apantisoun.
> >>
> >>P.S. Oi distro pou exo kaneis tis dokimes mou itan me RH 7.2 kai 8.0, 
> >>Debian Potato kai Woody kai me heartbeat oti teleytaio vrika sto 
> >>linux-ha.org.
> >>
> >
> >Den 3erw an to heartbeat einai kapoio feature tou linux n' kapoio 
> >e3wteriko,
> >
> Eksoteriko einai kai mporei na vrethei sto http://www.linux-ha.org
> 
> >
> >commercial,
> >
> Commercial omos oxi.
> 
> >paketo pantws auto pou 8eleis na sumbainei einai na metaferetai
> >to pass state twn connections.
> >
> >To floating IP 8a thn parei o standby server profanws, gi' auto einai
> >floating :-)
> >
> Nai apla otan tin pairnei prepei na ksanakano connect. Diladi fantasou 
> na doso ena mget ena iso image 600 MB kai kata ti diarkeia tis metaforas 
> na ginei to takeover. Ayto pou thelo einai aytos pou travaei to iso 
> image na mi katalavei oti egine takeover.

E3artatai apo to poso e3eligmeno einai to software gia to resilience.

Sunh8ws to floating IP parousiazetai me to idio MAC address kai stous
duo servers opote to switch de 8a katalabei diafora. Apo kei kai pera
einai 8ema software. Des sto dodumentation tou Linux HA project ean
to sugkekrimeno functionality uposthrizetai.

HTH.

-- 
[george daflidis-kotsis - systems admin,web/e-commerce - gdk at demon.net]