bitcoin core – How do I get old blocks while running a pruned node?

Hello I’m trying to build a NodeJS app that fetches Bitcoin blocks, potentially old ones, and I’m running into issues. I’ve downloaded Bitcoin Core but I don’t have enough space to run a full node and so I opted to run a pruned one. However, when I go to query an old block it tells me that the block isn’t available in pruned mode. So my question is, why doesn’t Bitcoin Core query the block on the fly from another node if it doesn’t find it on disk? It clearly has the ability to do this, else how would it sync the blocks in the first place? If this is not possible with Bitcoin Core, could I build my own JS app that mimics the network calls used in the IBD to get blocks on demand, instead of saving them to disk? Also, I can’t use a 3rd party block explorer API because they don’t have all the features I want and they are less reliable.

Transaction has 135 confirmations,but bitcoin not received

I sent money via bitcoin, and I have 135 confirmations already, But according to blockchain.info, 6 confirmation enough for Bitcoin transaction. mine has 135 confirmation now but still didn`t receive it. How long can it be take more to receive it? and is it possible to happen like this?

Bitcoin address are correct, but still not received after 135 confirmation.
Is it possible to not receive it in spite of this many confirmation?…

bitcoin core – Why is a minRelayTxFee of 1000 sat/kb not equivalent to 250 sat/kw?

I thought vbytes were equal to weight units divided by 4

It is *, but rounded up to the next integer, so the implementation in bitcoind is :

int64_t GetVirtualTransactionSize(int64_t nWeight, int64_t nSigOpCost, unsigned int bytes_per_sigop)
{
    return (std::max(nWeight, nSigOpCost * bytes_per_sigop) + WITNESS_SCALE_FACTOR - 1) / WITNESS_SCALE_FACTOR;
}

(Where WITNESS_SCALE_FACTOR = 4).

In addition, bitcoind not only uses vbytes for user interface but also for mempool logic and the DEFAULT_MIN_RELAY_TX_FEE constant is set in vbytes :

static const unsigned int DEFAULT_MIN_RELAY_TX_FEE = 1000;

In order to check it for standardness bitcoind will compute your transaction size as rounded up (if not a multiple of 4), and will record your transaction feerate as rounded down.
It will then compare this to the minimum relay feerate (1000) : a feerate of 250sat per KW will pass only if the size of your transaction (in weight units) is a multiple of 4.

It might be clearer with code, here is a Python function which illustrates this behaviour :

>>> def bitcoind_fun(tx_weight, feerate_perkw):
...     fees = tx_weight * feerate_perkw // 1000
...     print("Your transaction will pay {} sats of fees, is {} WU large (a feerate of {}sat/Kw)".format(fees, tx_weight, feerate_perkw))
...     tx_vbytes_for_bitcoind = (tx_weight + 3) // 4
...     tx_feerate_vbytes_for_bitcoind = fees * 1000 // tx_vbytes_for_bitcoind
...     print("bitcoind reads your transaction as paying {} sats of fees for a transaction of {} vbytes, so a {}sat/perKvb feerate".format(fees, tx_vbytes_for_bitcoind, tx_feerate_vbytes_for_bitcoind))

Which if you run with a tx_weight which is a multiple of 4 will pass, otherwise it won’t :

>>> bitcoind_fun(1600, 250)
Your transaction will pay 400 sats of fees, is 1600 WU large (a feerate of 250sat/Kw)
bitcoind reads your transaction as paying 400 sats of fees for a transaction of 400 vbytes, so a 1000sat/perKvb feerate
>>> bitcoind_fun(1601, 250)
Your transaction will pay 400 sats of fees, is 1601 WU large (a feerate of 250sat/Kw)
bitcoind reads your transaction as paying 400 sats of fees for a transaction of 401 vbytes, so a 997sat/perKvb feerate
>>> bitcoind_fun(1602, 250)
Your transaction will pay 400 sats of fees, is 1602 WU large (a feerate of 250sat/Kw)
bitcoind reads your transaction as paying 400 sats of fees for a transaction of 401 vbytes, so a 997sat/perKvb feerate

So we use 253 as the feerate floor to always be safe :

>>> bitcoind_fun(1600, 253)
Your transaction will pay 404 sats of fees, is 1600 WU large (a feerate of 253sat/Kw)
bitcoind reads your transaction as paying 404 sats of fees for a transaction of 400 vbytes, so a 1010sat/perKvb feerate
>>> bitcoind_fun(1601, 253)
Your transaction will pay 405 sats of fees, is 1601 WU large (a feerate of 253sat/Kw)
bitcoind reads your transaction as paying 405 sats of fees for a transaction of 401 vbytes, so a 1009sat/perKvb feerate
>>> bitcoind_fun(1602, 253)
Your transaction will pay 405 sats of fees, is 1602 WU large (a feerate of 253sat/Kw)
bitcoind reads your transaction as paying 405 sats of fees for a transaction of 401 vbytes, so a 1009sat/perKvb feerate

By the way the comment in the code you put is wrong : it’s not (3 * weight) / 4 but (3 + weight) / 4.


* Excluding sigop stuff.

PS: In the same vein, see https://github.com/bitcoin/bitcoin/issues/13283.

transactions – What is meant by Bitcoin dust?

To understand ‘dust’ you must understand a few things:

Firstly, a UTXO is an unspent transaction output. This is essentially a piece of bitcoin somewhere on the blockchain that is unspent.

To create a transaction, 1 or more UTXOs are used to form the inputs, and 1 or more UTXOs are “born” in the process. After the transactions are confirmed, the UTXOs that formed the inputs are now just “TXOs” (ie. they’ve been spent).

To ensure a transaction is confirmed, a fee must be added, that fee is proportional to the overall size of the transaction, which is the number of bytes the transaction takes up on the blockchain. The more UTXOs are used as inputs, the bigger the transaction will be, thus the higher the fee that needs to be paid.

If I have 1 BTC stored in 1 UTXO, it will cost me less to send that than 1 BTC spread across 10 UTXOs of 0.1 BTC, and it will cost me less to send that than 100 UTXOs of 0.01 BTC.

The fees are calculated as satoshis per byte, and the fees fluctuate depending on how busy the network is.

Every UTXO you want to use in a transaction will incur an increase in fee.

Every UTXO takes up a number of bytes in the transaction.

If you multiply fee per byte by the number of bytes taken by the UTXO and it exceeds the value held in the UTXO, then this UTXO is said to be ‘dust’.

So a ‘dust’ UTXO is a UTXO that isn’t worth including in a transaction because to do so would incur a fee increase higher than the value of the UTXO.

trading – How does the Bitcoin forex work?

No, it’s all the same. Well, maybe there are some very small differences, but in general it’s the same as forex. I would say that the cryptocurrency is much more unstable, and this is why I prefer trading CFDs on Investous broker. I am much better in that area, and it’s much easier for me to analyze this market. However, it has the same thing at base, so, if you are already good in one area, you will be successful in the other one too. I would suggest reading more information about that on the internet, there is a lot of information available on that topic

Allowing Incoming Connection on Bitcoin Core

Good Evening,

I recently installed Bitcoin Core v0.12.1 on my home server (running Windows 7) and wanted to allow it to accept incoming connections and used the guide found here: https://bitcoin.org/en/full-node#windows-7 to ensure I did everything that was needed. Unfortunately, it hasn’t been showing any incoming connection and when I used the connection tool recommended in the guide (https://bitnodes.21.co/#join-the-network), it says my server is unreachable.

I have already setup port forwarding for port 8333 to both my server’s IP address, 192.168.1.105 (wireless) & 192.168.1.129 (ethernet). I ran a port scan on the following websites and they all indicate that Port 8333 is open:

  1. Ping.eu Port Check
  2. WhatMyIP Port Scanner
  3. T1 Shopper Port Scanner

(I would provide links for the above scanners, but I cannot post more than 2 links)

I also created two rules in Windows Firewall (under Inbound Rules) with the following properties:

  1. Local Port – 8333
  2. Remote Port – All Ports
  3. Scope – Local & Remote IP address set to Any IP Address
  4. Domain, Public, and Private all checked
  5. All programs that meet the specified conditions checked
  6. Set to allow the connection
  7. Rule is enabled

There are two rules with the above settings, one for TCP and one for UPD. Even with all the above setup, the “Join the Network” tool on Bitnodes website (second link from the top) still says my node is unreachable and the debug window inside the program shows 0 incoming connections and 8 outgoing connections.

I’m not sure what else needs to be setup since I completed everything in the guide and port 8333 is definitely open. Any help or information with this issue would be greatly appreciated. Thank you in advance.

Dominick

merchants – Should a casino manage its own Bitcoin wallet?

Integrating your casino with a 3rd party payments processor translates to much easier bootstrapping for your casino but also higher operating costs. Higher operating costs in turn means that your are by definition less competitive, as you will not be able to provide your users with a smaller over-round and also you won’t be able to control the deposit and withdrawal costs.

Another thing to consider is security; having a 3rd part service deal with your money means that if they fail, you fail; if they vanish, your money vanishes with them.

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How To earn free bitcoin playing fruit slot machines on telegram – Other Money Making Opportunities

Do you have blockchain wallet then you can get free bitcoin just by playing fruit slot machines games on telegram play for free earn real money,Accept bitcoin payment method.

below is the link to join and also my earnings.

https://t.me/BTC_Fruit_v50_bot?start=1065362956

 

 

Screenshot_2020-05-23-01-18-47.png

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Experts says 3rd bitcoin halving is not the same with previous halvings

Some experts says that the 3rd bitcoin halving will not be as same as the previous ones, as they stress that with previous halvings the miners have most of the bitcoin to sell, but with the 3rd halving most of the bitcoin’s are already in circulation in different markets and exchanges, miners will only have smaller amount of bitcoin to sell this time. They also said that bitcoin price might not rise any time soon.