FlexHub Forum

Protocol talk => NMDC Protocol => NMDC Extensions => Topic started by: FlipFlop™ on April 26, 2011, 09:26:15

Title: $FailOver
Post by: FlipFlop™ on April 26, 2011, 09:26:15
Based on it's ADC counterpart, the FO extension (http://adc.sourceforge.net/versions/ADC-EXT-1.0.6.html#_fo_failover_hub_addresses), I suggest implementing failover addresses for NMDC too.

This will provide the client with one or more alternative addresses (another hub, or a network array) to connect to in case the hub becomes unavailable for whatever reason (server crash, ISP trouble, DDOS etc).
The client could keep polling the original hubaddress to see if it's back online again and take action based on client settings.

Protocol:

$FailOver <address1[:port]>,<address2[:port]>|

Example of a part of the client-hub login:
Client:    $Supports ... FailOver|
Hub:$Supports ... FailOver|
Hub:$FailOver someaddress.no-ip.org,adc://someotheraddress.com:5432|

The $FailOver command can be sent by the hub at any time, after the $Supports reply from the hub, overwriting/replacing addresses of any previous $FailOver commands. An empty $FailOver command will clear the addresses and simply keep waiting for the hub to get back online: $FailOver|

(edited: added specifics)
Title: Re: $FailOver
Post by: LadyStardust on April 26, 2011, 10:17:16
Would be especially useful to DC networks still using NMDC. Will also prevent loosing those users who close the hub tab when it goes offline.  :D
Title: Re: $FailOver
Post by: TraN on April 26, 2011, 10:25:02
So, excuse a noob for asking, but how does the client get the failover address if the hub is offline?  :)
Other then that, great initiative, since nmdc is still widely used, it still needs development  8)
Title: Re: $FailOver
Post by: FlipFlop™ on April 26, 2011, 10:30:42
The alternative addresses are sent to the client during login, ofcourse it needs a succesful login for the failover addresses to work, but the client will then store the alternatives for when the hub isn't online anymore. I suggest the client stores the failover addresses in the hub favs section.
Title: Re: $FailOver
Post by: TraN on April 26, 2011, 10:36:33
Ah, that makes sence then =) Would be a great idea if youre asking me.
Title: Re: $FailOver
Post by: LadyStardust on April 26, 2011, 10:49:14
The whole idea of the extension is great, as many others, the point is that much more of DC world can benefit from it. Imho it would be nice to have some good ideas spread around and be implemented in more and more DC software. Also making NMDC alike ADC in this matter would be good for FlexHub and avoid any future confusion caused by different features and settings for each protocol.
Title: Re: $FailOver
Post by: FlipFlop™ on April 28, 2011, 00:34:22
FlexHub will have the NMDC $FailOver and it's ADC counterpart the FO extension implemented on the next update, expected this week.

Client devs are invited to do the same ;)