Bitcoin Forum

Bitcoin => Bitcoin Technical Support => Topic started by: rupy on August 08, 2015, 11:30:00 PM



Title: Use blockchain of another bitcoind
Post by: rupy on August 08, 2015, 11:30:00 PM
I'm now running 3 nodes. But I only need 1 blockchain. Is there a way to point 2 of my bitcoind's to the third and only have that one download the blockchain?


Title: Re: Use blockchain of another bitcoind
Post by: achow101 on August 09, 2015, 02:46:01 AM
You can use other SPV wallets to do this, but I don't think Bitcoin Core can do that.

You could also share the blockchain data directory of that node and have each wallet have its data directory pointed to that one. Then you can change the wallet name on each node so that each one has a different wallet. The problem is that if that node is compromised, the Bitcoin in all three wallets can be lost.


Title: Re: Use blockchain of another bitcoind
Post by: shorena on August 09, 2015, 07:16:29 AM
I'm now running 3 nodes. But I only need 1 blockchain. Is there a way to point 2 of my bitcoind's to the third and only have that one download the blockchain?

Not if you want them to run at the same time.


Title: Re: Use blockchain of another bitcoind
Post by: rupy on August 09, 2015, 01:10:14 PM
Also forgot to mention they are on 3 separate machines.

I think it might make sense to divide the responsibility between replication and synchronization of data (router) and verification and manipulation of that data (wallet) with a simple API.

Synchronization and verification has some common traits, but to have a tight bond between the wallet and the blockchain might become too rigid soon. importaddress is a move in that direction, where you can have the private keys somewhere else and still use the bitcoind to receive and notify transactions, with trust but without security.

But you still need the full blockchain to sign and send a transaction securely, that's why it would be nice to have a really lightweight sending capable client that communicates with a trusted "receive and notify" blockchain to sign the outgoing transactions. Is that what bitcoin-tx is supposed to be?

I think this has been out of the secure distributed nature scope of the development so far, but now unless pruning is 100% secure, we have this issue.

Having a microservices oriented approach to the bitcoind might starve out memory leaks quicker too.


Title: Re: Use blockchain of another bitcoind
Post by: achow101 on August 09, 2015, 02:16:25 PM

But you still need the full blockchain to sign and send a transaction securely, that's why it would be nice to have a really lightweight sending capable client that communicates with a trusted "receive and notify" blockchain to sign the outgoing transactions. Is that what bitcoin-tx is supposed to be?
You don't need to have the full blockchain in order to sign a transaction. In fact, you don't need the blockchain at all. That is how offline wallets work.

What you pretty much described is the principle behind SPV wallets.

bitcoin-tx is not an SPV wallet. It is simply a command line utility for transactions.