Updates & Forks - Discussion

Blockchain and Bitcoin 101
#671

I have a couple questions around this subject:

What is the exact trigger for a miner to start working on a new block? is it when they receive a copy of the blockchain with an extra block and they also approve of that block?

another question, if for example an update happens to bitcoin (from 1 to 2 mb blocks) and miner A updates and miner B doesn’t. Miner A will now accept larger blocks and miner B will ignore the larger blocks. Now a Fork happens and you get 2 different chains. Do these chains still use the same mempool/ transactions?
I assume the chain of miner A (and everyone else that updates) will become the new used blockchain for BTC? as the update was executed on purpose.

What happens to Miner B (and everyone who doesn’t update) who will still be mining according to the old consensus? Will he still get block rewards? Will there be a new coin/cryptocurrency linked to the UTXO’s that will devolop on this chain (like btc gold)? what happens to the old UTXO’s on the chain as they share the same history as Bitcoin (chain A).

Thx in advance, I have learned a lot with this course sofar!

#672

Correct.

A hard fork creates two versions of the blockchain which are not compatible with each other. This means that nodes running on the new version of the blockchain will not recognize transactions being made on the old version, and vice-versa.

As there is no change in the protocol, the miner will get his/her reward as before.

Actually the one with updated protocol create a new currency and anyone holding any amount of the native coin will also get the same amount of the new currency. This situation doesn’t automatically happen but you need to claim these coins. And each coin has a different claiming mechanism.

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#673

Hey filip, If the bitcoin network always goes for the chain with the most PoW, then how is it that a hard fork can permanently split the chain? Eventually, 1 chain will have more PoW than the other, so shouldn’t they converge?

#674

A hard fork is not backward compatible, so the old version no longer sees the new one as valid.

#675

Ahhh then that explains it, thanks a lot!

1 Like
#676

i had same question, thanks filip and rest of folks. Great community.

#677

Hi Filip, hope you are well.
If a Hard fork appears like BCH, How does that chain keep existing? I am sure that more blocks would have been confirmed on BTC therefor making it the wining chain.
Is it perhaps that the nodes that want to keep working on BCH just never update?
Thank you.

#679

A hard fork is not backward compatible, so the old version no longer sees the new one as valid. If we take BCH fork, the updated nodes can not choose BTC chain any more because it is not valid with their updated rule and vice versa.

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#680

thank you Filip for this very intrestinglesson, I had to look several times to the video, before I think I understand it now, but can you have a look, please.
If I understand it correctly: what you mean with update of the consensus rules. at least a majority the nodes has to accept them <= 50% makes them soft forks and with hard forks you have to convince 100% of the nodes.
hard fork update:
expand the set of rules that makes blocks valid who were before invalid because they were outside the old rule set. new updated blocks don’t fit within the old rule set
Soft fork update:
blocks that are created within the new ruleset, they fit within the old rule set so will be accepted by the nodes

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#681

yes actually you said that " you lose money " instead of that unaccepted TXs (blocks) going back to the mempool and waiting for the put in a block by the next miner

#682

Hello, i have a questions :

update : ohh i see the last part of the video and yes the majority decides :slight_smile:

¿ What happens when the nodes are update for the new rules ?, who decide this exactly ?
¿ If i have a node with a differents rules but working in the same blockchain i am doing a fork ?

i trying to understand this in deep because if the network is decentralized who decides when the rules gonna be changes ?

The only that i can thing is divide and decided in majority of nodes like the 51% of the community that has nodes and then the rules can changes, but i dont know if i am right

right know i have existential question, i have another episode of " i dont need sleep i need answers", after this message i go to search in google equal :slight_smile: :heart:

image

#683

A Bitcoin node is any computer that runs a Bitcoin implementation and stores the entire blockchain. And If you are running a node then it is you who decide to update the new set of rules or not.

There are two updates, one leads to hard fork and the second leads to soft work. With a soft fork, only one blockchain will remain valid as users adopt the update. Whereas with a hard fork, both the old and new blockchains exist side by side, which means that the software must be updated to work by the new rules. Both forks create a split, but a hard fork creates two blockchains and a soft fork is meant to result in one

Anyone can make an update but the problem is who gonna accept the new change if the community find it interesting they will update their nodes software for the new rules.

1 Like
#684

So when an accidental fork happens, the transactions in the stale block are permanent or reverted ?

#685

I am confused with hard forks.

Let’s say there is one. So it will create a new currency (like ETC and ETH). What becomes the composition of a wallet after a hard fork ? Like if you had 50 ETC before, does it mean that after the fork:

  • Your wallet on the chain that did not change will still have 50 ETC ?

  • Your wallet on the new chain will have 50 ETH instead ?

But if these 2 things are correct then we create coins but the amount they are backed on is still the same but they should decrease of value ?

#686

Hello Filip,

Am I correct in understanding the following?

Regardless of how many nodes update successfully, they will be less than 100% of the network. Because they (the updated nodes) are fewer than 100%, a chain split / hard fork occurs.
In a perfect blockchain ecosystem, 100% of nodes would update before a split would occur, and regrettably, this is unavoidable.

Is this the case?

RJ

#687

Once a transaction is made can not be reverted, but you can broadcast a new tx using the same UTXOs with a higher fee, ensuring the tx will be mined first thus invalidating the original tx. If the transaction is mined in both blocks then there is no issue, but at the time there is no way of knowing for sure if your tx is included in both blocks. Once the fork is resolved the nodes return transactions that were not in both blocks back to the mempool. When they are returning these transactions they validate them again if a tx was also part of the winning block it would mean its UTXOs are spent and the tx would be invalid (or already confirmed in another block) and not returned back to the mempool.

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#688

When a Bitcoin fork occurs, anyone holding any amount of bitcoins will also get the same amount of the new currency. This situation doesn’t automatically happen but you need to claim these coins. And each coin has a different claiming mechanism.

#689

Yes, you are correct😊.

#690

Thank you for helping me understand. I appreciate your help. :smiley:

#691

So you would have the same amount of the coin on the new chain andon the old chain yes ?
But the freshly created coin (from the hard fork) hasn’t any value locked to it right ? So its value is 0 ?