Perhaps I've misunderstood something here.
By matching Bitcoin and Namecoin block I'm thinking of an SHA-256 hash of [a list of Bitcoin transactions, some Bitcoin address information, and Namecoin data in a merkle tree] which happens to be a particularly low number (begins with quite a lot of 0s). It was my understanding that any hash small enough to generate a Bitcoin block would also be small enough to generate a Namecoin block and consequently I expected any merged mining Bitcoin block to have a corresponding Namecoin block (at least while Namecoin difficulty is less than Bitcoin difficulty).
This belief was made stronger by posts such as this:
https://bt.irlbtc.com/view/42667.msg566146#msg566146where slush proudly announced the first Bitcoin merged mining block (which had a Namecoin counterpart) Bitcoin 148744 = Namecoin 19274.
Can you guys explain why Bitcoin and Namecoin block generation events are not linked in this way? Are the corresponding random variables independent (in the sense of probability) and if so why?
Thanks.
The returning getwork hashes are passed to both nmc & btc clients. Either or both can find a block. To describe the whole process would be very lengthy.
I've just learned that with merged mining, more than 99% of Bitcoin blocks should each come with a Namecoin block. Check out
https://bt.irlbtc.com/view/33142.msg606537#msg606537.
If you have two or more examples of a share which generated a Bitcoin block but not a Namecoin block then I recommend looking into this and making sure that most BTC/NMC miners are working on headers with valid Bitcoin and Namecoin information most of the time. Caution: cgminer has had issues with merged mining because old versions doesn't like to change the block header when new work is pushed for Namecoin. The current version of PoolServerJ seems to be ok right now, even with cgminer, and you can see an example of it in action here: (
BTC and
NMC).
Love the "Blocks found over last week" graph! Good luck guys!
