We’re rewarding the question askers & reputations are being recalculated! Read more.

Questions tagged [forks]

forks are events where the blockchain consensus is not guaranteed and clients may have different states

Filter by
Sorted by
Tagged with
16
votes
3answers
3k views

TheDAO difference between a hard and a soft fork?

There are currently different scenarios examined which include soft or hardforking the ethereum blockchain to mitigate the DAO attack. What plans are there exactly and what are the difference between ...
16
votes
1answer
1k views

How should I handle blockchain forks in my DApp?

In the user interface of my DApp, how can I detect that a blockchain reorganization happened and what should I do to update the UI state once the fork is resolved?
12
votes
1answer
727 views

parity Ropsten testnet forked at block 296151?

I am seeing what looks like a fork in the Ropsten testnet at block 296151 (Jan 6, 11:14 PM UTC). Is this expected? My local Parity node (Parity/v1.4.7-beta-f2058bd-20161227/x86_64-macos/rustc1.13.0) ...
10
votes
1answer
837 views

How can I reliably induce a blockchain fork for testing purposes?

I would like to reliably induce a fork on a private testnet so that I can test the behavior of off-blockchain code that interacts with contracts. (see related questions as to why I would want to do ...
9
votes
1answer
368 views

When there is an unexpected hardfork, what is the procedure taken by the core team?

Imagine Ethereum had a hardfork like this one that Bitcoin experienced. Ethereum can learn from this and can be prepared to be more efficient during the crisis, minimize panic, minimize other ...
9
votes
1answer
1k views

How to check if a transaction is still in the blockchain?

Say we want to confirm that a value transaction tx has reached certain finality, which we define as waiting for 12 block confirmations. We do this to drop the probability of tx getting lost due a fork ...
7
votes
1answer
224 views

Would a fork require miners to update software it they mine on a pool?

Would a miner have to update their mining software, such as ethminer, to go on a forked version of the chain? Or is it up to the pool to decide which chain to mine? Also, if a miner is mining on a ...
6
votes
1answer
206 views

How do miners decide whether to fork or not fork?

How, as a technical matter, do miners express their desire to fork or not to fork? What happens with the miners that are in minority if they persist in mining on the unpopular branch?
6
votes
2answers
262 views

Do I need to prepare anything for the upcoming homestead release?

This is a canonical question. What actions should regular users miners and pool operators developers undertake to prepare for the upcoming homestead release which includes a forking mechanism.
6
votes
1answer
304 views

How to detect if block was forked?

It's is possible to track by API, if block was forked/orphaned? Will be glad to see some example.
5
votes
2answers
714 views

Cold Storage after a Hard Fork?

If you create a cold storage account, by following the method described here for example: How to send ether to a cold storage account? And subsequently, a hard fork takes place on the Ethereum ...
5
votes
2answers
723 views

Blockchain sync on geth stalls at block 1.1 million

I saw the responses on a few issues regarding ethereum and blockchain sync on this site, and was wondering if anyone could help me with a problem I'm facing. I've been trying to sync the blockchain ...
4
votes
1answer
717 views

What improvements will the upcoming Byzantium fork bring to Smart Contract development?

The Ethereum Team announced recently that the Byzantium fork will happen on October 16. This will be the first phase of the Metropolis upgrade. What improvements will the Byzantium bring to Smart ...
4
votes
3answers
333 views

Maximum known Ethereum fork length

What is the maximum known Ethereum fork length? What is the maximum Ethereum fork length in theory? Edit: please read fork length as maximum number of uncle blocks.
4
votes
1answer
709 views

If there is a fork, will the difficulty go down?

Say there's a fork with 51% of the hashrate going to the new version. I assume then that the hashrate of the new chain would be almost half of what it previously was for as long as other miners join ...
4
votes
1answer
173 views

Transaction propagation and acceptance on forks

Assuming the scenario where a fork occurs shortly after I have sent a transaction out, and it gets mined in my side of the fork, could it also be mined in the other side of the fork? In other words, ...
3
votes
3answers
1k views

Lost ether: wallet on some other chain

Yesterday I decided to move my Ethereum coins to my coinbase account from my PC based Ether wallet from Ethereum.org . I had 107ish coins. I sent 1.2 to my coinbase address as a test and they arrived ...
3
votes
1answer
180 views

How to check if a mining pool runs the forking client or not? [The DAO]

As Geth and Parity forking version are out, the switch to a soft fork related to The DAO is said to happend on block 1800000 if block gas limit is below or equal to 4M. We can see global gas limit on ...
3
votes
1answer
1k views

How to fork Ethereum from the current state?

I've read a lot of tutorials and guides that teach how to set up your own private network from scratch. However, how would I do that from the current state of the blockchain? Instead of generating a ...
3
votes
1answer
132 views

Low block confirmation time and forks

In Bitcoin the block confirmation time is set at 10 min using POW and DoD. This reduces the chance of conflicts (temporary forks) from nodes that simultaneously solve POW solution. How are these ...
3
votes
2answers
614 views

Is it still possible to replay a single transaction on ETC and ETH from a pre DAO-fork address? [duplicate]

If, for some reason, I want to spend both ETH and ETC to the same address in a single transaction right now, how would I do that? The ether is currently in a pre DAO-fork address.
2
votes
3answers
133 views

When will the EIP 2 fork kick in?

EIP 2 is a fork cleaning the protocol a little. When will the fork kick in?
2
votes
3answers
370 views

Want to run a local fork of Ropsten

I would like to run a local fork of Ropsten to interact with some of the smart contracts without having to fill up from the tap. My plan was to start a light parity node as follows: parity --chain ...
2
votes
2answers
38 views

Does the ETH blockchain have fundamentally more branching than BTC?

Intuitively speaking, ETH seemed to have simply increased the average block generation rate from one every 10 min in BTC to 1 every 15 seconds. There doesn't seem to be any other protection against ...
2
votes
1answer
24 views

Which semantics are used for old contracts executed now?

Suppose an old contract is called now that contains an opcode that was invalid then but has some meaning now. What happens when this opcode is executed during a recent transaction: Will execution fail ...
2
votes
1answer
735 views

Ethereum Hard Fork: what happened to legacy Ether?

I currently run Forked Ethereum via Parity. I'm assuming my Ether from before the fork is available on this chain. However, does it also still exist on the Ethereum Classic chain? I tried researching ...
2
votes
1answer
191 views

Is ethereum based on bitcoin?

There are many discussions about so called altcoins. Is Ethereum an alternative coin? Is Ethereum even a coin? (This is a canonical question to gether answers and resources on that subject.) Is ...
2
votes
1answer
190 views

What is a “51% spawn camp attack”, and is it any different from a normal 51% attack

What is a "51% spawn camp attack", and is it any different from a normal 51% attack. Saw this mentioned in this tweet from Vitalik. Is there a distinction that I am missing?
2
votes
1answer
231 views

What happens if a miner who didn't soft fork mines an “invalid” block?

Can someone explain, technically, what would happen if a majority of the miners adopted a soft fork (forward-compatible) making some tx invalid and then a miner who didn't fork happened to mine a ...
2
votes
0answers
60 views

How can I extract sidechains (transient forks) from a geth node before they get discarded?

According to my understanding, transient forks (also known as sidechains in geth's source code) are discarded or overwritten when a reorganization happens. But before that, when the node detects a ...
2
votes
0answers
36 views

Ropsten issues - two forks happening, transactions showing in both places

There seems to be a few issues going on with ropsten right now: https://twitter.com/sbetamc/status/1092167042709573633 https://twitter.com/stevenleeg/status/1092546643604459521 At the same time, a ...
2
votes
0answers
33 views

Geth Clique: can change config params in genesis and still retain the existing blocks?

I have altered my custom Geth private chain Clique PoA, but it seems after I do that I encounter: BAD BLOCK Error: invalid receipt root hash Is it possible to: change the Geth code add a new hard ...
2
votes
0answers
238 views

What does Vlad Zamfir mean by 'the fork-choice rule is stateful'?

Does he mean the rule to determine the next blockchain requires knowing the state of currently bonded validators? This “out-of-band authentication only necessarily once” property is what Vitalik ...
1
vote
1answer
25 views

“Fork choice rule” : A general term? or a specific algorithm?

Is "Fork choice rule" a general term including all the algorithms used for choosing a branch among other branches in a fork (including longest chain rule etc) ? Or is it a specific algorithm designed ...
1
vote
1answer
91 views

Is a truffle migration effectively the same thing as a fork?

I'm confused as to the distinction between a migration (in truffle) and a fork (project, not ethereum). After the initial migration (deploy), any future migrations create new contracts with new ...
1
vote
2answers
46 views

How is the state “undone/reverted” after a longer chain is determined?

So say there is block_a, and block_b, both at height 1677. And a node accepts block_a, but then recieves block_b + block_c (which is mined on top of block_b), how exactly are the state changes made in ...
1
vote
1answer
101 views

Whats the cheapest way to fork an ERC20 token when you have all addresses and values?

If you have a copy of the mapping of the owners/allowance of the tokens you'd like to fork. I couldn't find any contracts that seemed to be able to this.
1
vote
2answers
44 views

Will my transaction get lost if it's in a block which was forked due to double-spending?

I have a contract which I need to update occasionally. This update has nothing to do with "real money transfer". It deals only with the value of a state (global) variable in my contract. Also, I am ...
1
vote
1answer
325 views

Am I now protected from replay attacks?

I had five accounts on ETH before the hard fork with various balances. Over the last few days, I've sent all the ether in all of those accounts to Kraken. When I was done with that, all of my ether ...
1
vote
1answer
44 views

How to prevent fork in poa network?

I discover that forks in poa network can happen! I have 4 nodes (trusted nodes) I want to create a poa network with no forks, is it possible ?
1
vote
0answers
99 views

Why is my geth node stuck on block 7130891?

My geth mainnet node (version 1.8.21) has stopped on block 7130891. Interestingly, eth.syncing returns false and eth.blockNumber constantly returns 7130891. It was working up until ~24 hours ago. ...
1
vote
1answer
125 views

What happens with transaction after the block fork?

Do I need to generate transaction again after fork? How many confirmations are minimal to be sure of the transaction?
1
vote
1answer
90 views

Fork mainnet into PoA/clique network

How to to fork Ethereum main net (from latest block) into a non-official chain that can only be mined by PoA/clique using geth? Preference for keeping geth code untouched if possible. As expected, ...
1
vote
1answer
79 views

Spoon vs fork vs airdrop

Can someone explain the exact differences between the three? I'm most familiar with the fork, where the rules of generating blocks change creating a fork where miners can choose to follow the old ...
1
vote
0answers
40 views

What precisely classifies an off-chain block as a fork?

I am looking for validation (or invalidation) of my assumption of what strictly counts as a fork in Ethereum. If you start filters to multiple ETH nodes at the same time, you will very often see 2 or ...
1
vote
0answers
330 views

DB - How do I roll back to a block height?

I was informed on this post that I was, indeed, on a fork. My client starts syncing and encounters a discrepancy with my local DB copy. My peers then vanish. In my case, it would be a great hassle if ...
1
vote
0answers
43 views

Node running on testnet doesn't match etherscan explorer [duplicate]

Two of my nodes running geth version 1.5.3 have been working great on testnet since 24th November 2016 by using this command: geth --rpc --datadir /mydatadir/.ethereum/testnet --networkid 3 but ...
0
votes
1answer
31 views

Constantinople gas change, reentrancy possibilities

With the new reduced fee for using SSTORE for 'dirty' storage slots, is it possible to re-enter a function from a send() or transfer() and have the contract call send() or transfer() again? Or is it ...
0
votes
1answer
21 views

Will there be an Ethereum Constantinople Fork coin and which exchanges would be supporting it?

There are reports of nodes that still haven't upgraded their Ethereum nodes and they are on the Ethereum Constantinople fork. Would a new coin exist and which exchanges have shown support for ...
0
votes
1answer
29 views

Is the result of getBlockByNumber final?

Will the result of getBlockByNumber change due to the longest chain issue? Say, I called getBlockByNumber(100000) now and got block A. 10 mins later, it turns out block A is not in the longest chain. ...