Precisando fazer umas operações de varredura (sweeps) em umas carteiras e endereços antigos, achei alguns detalhes sobre o processo de transmissão das transação para os mempools através do meu nodo completo que compartilho aqui.
There are some legacy bitcoin keys which produce vanity
addresses, such as
1Bio* made with
and some legacy wallets made with
needed to be swept to segwit addresses as transaction fees are
doomed to get very high on the main chain as time goes on.
Some time ago, Adreas Antonopoulos said in one of his lectures the best way to do that is to sweep the old wallets. Moving utxos to a single address will reduce the size of the following transactions but sweeping may generate a large transaction (in bytes) because it can contain various unspent outputs. That is why it is a good idea to do sweeps leisurely, with time at hand and aiming for low fees..
I can sync my full node that lives in a USB hard drive with the
network. I have got the
bitcoind inbound port open to
get other nodes to sync with me (including the mempool). I
just don't mine nor use
bitcoind with my wallets
because I rather prefer
Electrum to manage them.
I have been trying to set sweeps with small transaction fees, such as 1-6 satoshi/Byte.
Notes on broadcasting transactions from my full node
As many of the readers may be aware, most
mempools will not accept transactions with very low fees and their
threshold is much higher than the minimum of 1sat/B as the default
relay (broadcasting) fee.
What the reader may not be aware of is about the minimum
The amount of system memory allocated for
unconfirmed transactions is defined with the option
maxmempool defaults to 300MB
of RAM. Once the maxmempool-memory is fully used, the lowest-fee
transactions are dropped from the nodes mempool and
mempoolminfee is increased to reject lower-fee
Transactions may be dropped from the mempool just a few minutes after they are added or until 336 hours (two weeks) or after even longer.
Andreas Antonopoulos said he can get most of his transactions through with 1sat/B fee, so I reckon he keeps broadcasting his transactions through his own node until they are taken in a block or he gives up.
Andreas said that even though transactions marked with the flag
Replaceable By Fee (RBF) are less dependable than
non-flagged transactions, all of his transactions are marked as
RBF. It should not really make much of a difference but if a
transaction is not marked as RBF,
bitcoind will not
just double-spend the same utxo while the old transaction
is in your local mempool and will throw out a broadcasting error,
whereas RBF transactions are promptly double-spent and the older
transaction (conflicting transaction) is removed from the local
Andreas also remarked that RBF transactions may be replaced by the sender, while Child Pays For Parent (CPFP) transactions are made by the recipient.
I decided to use
Electrum to make and sign the
sweep transactions and then broadcast them through my own node.
The first time I messed with those sweep transactions, broadcasting a bunch of to my local mempool and soon blockcypher could detect them in various other mempools, too.
After less than 24 hours, no transaction could be found in other mempools by blockcypher, but they still persisted at my local mempool.
bitcoind-daemon, those old
transactions were rebroadcasted from my local node and could be
detected by blockcypher again. So if you don't want to
rebroadcast old transactions accidentally, be sure to remove
bitcoind starts or
mempool.dat is created by dumping mempool data from
To keep rebroadcasting your own transactions, be sure to set a
large enough value for
maxmempool size so your
transactions are not outside
I will keep trying some more experimentations with low transaction fees and broadcasting them from my own node to see how many, if any at all, will be confirmed in the following few days.. So far, only one transaction with feed ~6sat/B got to the blockchain, but that is higher than I want to pay for the other transactions..
Tip: if you are using the clipboard and dealing with private keys, beware not to paste one of them in a block explorer as I did.. Ideally, don't connect your computer to the internet while dealing with private keys. This avoids many problems.
- Strategies to save off Bitcoin fees?, see tranthidung commentary
- Unconfirmed transaction
- It is pointless if the BTC fees increases along with rise in BTC price!, this is a long discussion and seems interesting..