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Questions tagged [forks]

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

2
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2answers
27 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 ...
0
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0answers
24 views

Why does my private network transaction use a different amount of gas than my mainnet transaction performed immediately after?

I am forking the mainnet from my own geth node with ganache-cli --fork option. Immediately after the fork, I simulate a transaction to a contract on the forked, private network. I then immediately ...
0
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1answer
31 views

Possible replay attack when paying to smart contract

I am afraid of a possible replay attack when paying to a smart contract. Given these 3 assumptions An action gas cost may change according to the state of the blockchain (even if its the same action)....
0
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1answer
25 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 ...
2
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0answers
27 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 ...
1
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0answers
41 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. ...
0
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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 ...
2
votes
1answer
19 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
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0answers
24 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 ...
1
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1answer
119 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
66 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
2answers
34 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 ...
3
votes
3answers
178 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.
1
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1answer
61 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
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2answers
36 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 ...
0
votes
1answer
27 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. ...
0
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1answer
67 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
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0answers
38 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 ...
2
votes
3answers
311 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 ...
0
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3answers
59 views

Question on the security of forks

Reading the whitepaper of Ethereum I came up with the following questions on forks. Let me explain: Lets say that I send 1 ETHER to an address A1 to buy something and this transaction gets logged on ...
2
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0answers
199 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
85 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 ...
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 ...
0
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1answer
181 views

What happens to ICO tokens on the Ethereum chain after a hardfork? Are they valid on both chains?

With the Ethereum Metropolis hard fork coming up, what happens to ICO tokens like Steemit and all the others built on top of the Ethereum network? Do they automatically fork too?
4
votes
1answer
705 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 ...
1
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0answers
295 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 ...
6
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1answer
255 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.
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2answers
3k views

What happens to wallets during a hard fork?

What happened to "Ethereum" wallet balances when Ethereum was forked from Ethereum classic? For example if someone had a wallet prior to the fork, would that wallet then be compatible in both ...
2
votes
1answer
181 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?
5
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2answers
677 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 ...
3
votes
2answers
585 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.
1
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0answers
42 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 ...
11
votes
1answer
714 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) ...
3
votes
1answer
129 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 ...
-4
votes
1answer
85 views

Forking example - Ethereum 101 [closed]

In the forking example on Ethereum 101 course on b9lab's website, could someone clarify why transaction 7 appears in ledger fork 1? Thanks! https://academy.b9lab.com/courses/B9lab/X16-0/2016/...
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 ...
1
vote
1answer
322 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 ...
2
votes
1answer
687 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 ...
4
votes
1answer
169 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
1answer
179 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 ...
15
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 ...
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 ...
6
votes
1answer
199 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?
2
votes
1answer
225 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 ...
4
votes
1answer
698 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 ...
7
votes
1answer
221 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 ...
3
votes
1answer
185 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 ...
5
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2answers
720 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 ...
10
votes
1answer
707 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 ...
6
votes
2answers
261 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.