Funding Cyrus High Availability

David Lang david.lang at
Sun Sep 19 19:54:50 EDT 2004

please don't misunderstand my posts. it's not that I don't think that 
active/active/active is possible, it's just that I think it's far more 

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

now this doesn't mean that all ofs must be done in this funded project. I 
believe that people would end up going from #1 or #3 to #2 or #4 by 
individuals coding the required pieces and sharing them (#4 has as much of 
a jump over #3 becouse of all the different senrios that are involved, 
each one is individually simple) however #5 and #6 are significantly more 
difficult and I would not expent them to just happen (they are also much 
more intrusinve to the code so there is some possibility of them not 
getting merged into the core code quickly)

David Lang

-- There are two ways of constructing a software design. One way is to 
make it so simple that there are obviously no deficiencies. And the other 
way is to make it so complicated that there are no obvious deficiencies.
  -- C.A.R. Hoare

P.S. #1-4 all could qualify as the first way, #5 and #6 are both 
complicated enough to start with that it is really hard to keep them out 
of the second way
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