Funding Cyrus High Availability

David Lang david.lang at
Mon Sep 20 13:00:53 EDT 2004

On Mon, 20 Sep 2004, David Carter wrote:

> On Sun, 19 Sep 2004, David Lang wrote:
>> assiming that the simplest method would cost ~$3000 to code I would make a 
>> wild guess that the ballpark figures would be
>> 1. active/passive without automatic failover $3k
>> 2. active/passive with automatic failover (limited to two nodes or withing 
>> a murder cluster) $4k
>> 3. active/passive with updates pushed to the master $5k
>> 4. #3 with auto failover (failover not limited to two nodes or a single 
>> murder cluster) $7k
>> 5. active/active (limited to a single geographic location) $10k
>> 6. active/active/active (no limits) $30k
>> in addition to automaticly re-merge things after a split-brin has happened 
>> would probably be another $5k
> I think that you are missing a zero (or at least a fairly substantial 
> multipler!) from 5. 1 -> 4 can be done without substantial changes to the 
> Cyrus core code, and Ken would be able to use my code as a reference 
> implementation, even if he wanted to recode everything from scratch. 5 and 6 
> would require a much more substantial redesign and I suspect quite a lot of 
> trial and error as this is unexplored territory for IMAP servers.

Thanks, this is exactly the type of feedback that I was hopeing to get. so 
you are saying that #5 is more like $50k-100k and #6 goes up from there

Ok folks, how much are you really willing to pay for this and since the 
amount of work involved translates fairly directly into both cost and time 
how long are you willing to go with nothing?

David Lang

> -- 
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