Questions tagged [blocks]
This tag is for questions dealing with the structure of blocks.
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1answer
27 views
How to get the value of the transaction?
I am using web3.py but I need help to know the value of the transaction sent.
I know that the information is stored in the input but how do I parse the string. I know nothing about ABI.
Here is the ...
0
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1answer
13 views
changing source of random number based on reward?
Would this be an acceptable way to produce a random number dependent on the reward?
Say if the reward is high enough to entice a miner to manipulate the block then the contract will utilize oraclize.
...
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0answers
44 views
Modify number of confirmations
By default there are 24 confirmations but I am running a testnet with just 3 miners and I would like to change this number bucause it makes not sense to have 24. I have been checking ...
0
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0answers
8 views
How to read the data from block?
In my smart contract, I am inserting plain text message.
I can also update the message.
After updating, if I want to see the previous message, is it possible?
Can I see all the data in etherscan.io?...
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0answers
17 views
How to mine a Empty Block or reject transaction?
How Can a miner can mine a empty block,reject honest transactions to be added into block ; does it mean we could tweak the miner client , if yes could someone tell how it is done and what are the ...
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1answer
113 views
How can i implement deadlines in smartContract?
Suppose I am running a gallery and ask participants to submit there paintings before a specific date. After passing that date participant should not be able to submit their entry. How can I implement ...
1
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1answer
15 views
Make sure I don't jump any blocks
I'm making a simple program to track transactions in and out of an address, I have a function that gets the latest block and then I run it consecutively.
When I run the function sometimes the block ...
2
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0answers
33 views
How to read block propagation delay from ethstats.net?
I am wondering what is the average (or mdeian) time it takes to propagate a block in the Ethereum blockchain?
I found ethstats.net provides a cummlative graph for block block propagation but do not ...
1
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1answer
20 views
How to change all the ethereum blocks from C drive to D drive — question about the answer
I'm new here and have no idea if this is the right way to respond. So I duplicated the question a have a question about:
I've done the things written in the answer on the original question and I ...
0
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1answer
21 views
Is there multiple chains of block in ethereum network?
Since blockchain is a chain of blocks,
In ethereum,
1. is there only one chain of blocks
2. are there multiple chains of blocks.
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0answers
37 views
What actually a block contains, is the data inside it a virtual or physical entity?
My understanding of a block in blockchain is that it is a data structure that contains information like Block Size, Block Header, Transaction Counter and then Transactions. Deeper in the Block Header ...
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1answer
57 views
How State variable are stored and updated?
The Smart contract and the state variables are stored in the blockchain, let us say during deployment of a smart contract the state variable and smart contracts are stored in the block 1, and in ...
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1answer
23 views
Looking for an Ethereum sniffer
I have been looking for a sniffer similar to Bitcoin P2P Network Sniffer (https://github.com/sebicas/bitcoin-sniffer) which could allow me to connect to Ethereum nodes and listen to blocks and ...
1
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1answer
30 views
Getting the last synced block is 0
I am trying to get last synced block but it always 0.
So I have run
geth --syncmode fast -cache 4096 --rpc
Here is a logs
INFO [12-19|09:47:50.058] Imported new state entries count=...
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2answers
53 views
Who generates the mathematical problem for miners?
In POW miners solve an problem for successfully mining a block, who provide the question to the miners ?, does all miners work on same problem ?, and how the miners verify the answer ?, if the problem ...
0
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1answer
27 views
how to get the last incoming transaction before date
I need to get the incoming transaction before the date currently i use
https://web3api.io/api/v1/addresses/0xaD4b04Df17f2d35F81771Fa124dBD94E33587F4c/transactions?to=...
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0answers
34 views
Get blocks between dates
I am trying to get the block between dates . for that i use web3.js . per day average block is 6172 so if i need previous day block i use below code
fromBlock: (await web3.eth.getBlockNumber()) - ...
0
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2answers
49 views
can only change header's extra data to mine a new block? [closed]
Fix 'nonce' and 'mixDigest', only change 'extra' to mine a new block.
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1answer
23 views
How will Proof of Stake affect blockhash generation
When (and if) Ethereum switches to proof of stake, how will the hash of blocks (most likely) be set?
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0answers
35 views
Ethereum Blocksci parser tool
I need a blocksci parser for ethereum.
I am using https://github.com/citp/BlockSci for bitcoin .
Is any similar blocksci parsing tool for ethereum?.
1
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2answers
30 views
0 txn in mined block [duplicate]
How is it possible for a block to be mined with 0 txn?
https://etherscan.io/block/6739171
That's an easy way to get 3 ETH block rewards.
1
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1answer
16 views
Is state read from the current or previous block for external function calls?
Given that a computer must execute in a sequence, I assume the VM is also doing so before deciding the final block state. Let's say my contract calls an external function from another contract that ...
8
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2answers
212 views
Possible error in white paper validation algorithm?
If we take the block validation algorithm described in the
white paper (Section Blockchain and Mining), it states at point 6:
Let TX be the block's transaction list, with n transactions. For all i ...
3
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0answers
13 views
Will block numbers be sequential on a sharded blockchain
When Ethereum shards (assuming it does) will the block numbers across the multiple shards be unique? I doubt it (I don't think the shards can have sequential block numbers and be independent of the ...
1
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1answer
22 views
Does a non-miner node validate both single transactions and an entire block?
My understanding is that an originating node broadcasts a transaction to its neighbours, who all validate the transaction to ensure (a) the signature is valid and (b) the state change is valid, before ...
2
votes
1answer
32 views
Is there any point in adding msg.sender to an event?
I am asked to provide the value of msg.sender as part of an event emitted in a function.
It is something like:
contract MyContract {
event MyEvent(address indexed sender, uint256 input, uint256 ...
0
votes
2answers
80 views
How to get multiple blocks timestamps with a single JSON RPC call?
Is there a way to get data similar to the ones provided by web3.eth.getBlock(blockNumber) but with multiple blocks at once?
The goal is to get the timestamps for 100 blocks in a row without ...
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0answers
78 views
Same Block Received More Than Once With Same Block Parameters
Use Case:
I am implementing a deposit system where I will get a block as it is mined and parse transactions to check for a deposit of Ether or a specific token. Getting the same block twice will ...
1
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1answer
317 views
How can I retrieve the transaction hash / block hash of a contract that has already been deployed?
If you use Web3.py to deploy a Solidity contract to the blockchain, you can retrieve a transaction hash, like this:
tx_hash = w3.eth.sendRawTransaction(signed.rawTransaction)
Once you have that ...
0
votes
1answer
110 views
How to read previous blocks data?
I'm new to block chain technology. I'm trying to store and read blocks using testRPC along web3.js. I'm able to get the latest block data but not able to fetch previous blocks data. Please some one ...
1
vote
1answer
31 views
Why is LH repeated in equation 35 of the yellow paper?
Excerpt from page 5 of the yellow paper, version e94ebda:
I understand that LX is the preparation function for serialising X, as follows:
LB for blocks
LH for block headers
LU for ommer block ...
1
vote
1answer
357 views
How the blocks and tries are stored
Newbie here!
I still not sure if I understood how some structures of Ethereum are physically stored (assuming Geth implementation)
State Trie: only one off-chain Merkle Patricia Tries stored using ...
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0answers
141 views
What does total number of blocks per day mean in Etherscan?
I tried to figure out what does total number of blocks per day means here and on the Internet, but i failed. For example, the number of blocks on 26 Aug is 5947 [here https://etherscan.io/chart/blocks]...
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1answer
54 views
Why are timestamps stored in a uint (256 bit) when they would fit in a uint64?
A (signed) 64 bit timestamp can store a date much larger than the age of the universe.
On many platforms this would be a micro-optimization, but in the context of Ethereum, we want to squeeze every ...
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1answer
1k views
Block time and confirmation time
I have been reading in different papers and comments these two concepts and I would like to know the difference between them(if there is, sometimes it is a bit confusing).
I understand that the block ...
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0answers
37 views
Why is my transaction not included into blocks with smaller gas prices in them?
I created a transaction with gas price 1.1 GWEI. It has been pending for 3 hours, and yet - during just the last 75 blocks - several 1 GWEI transactions have been included.
In other words, gas price ...
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0answers
23 views
How the default block in Parity is set
How function setting default block (going back in history) in parity is implemented looking from algorthmic side?
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2answers
893 views
Basic Blockchain Implementation: how is the blockchain on a given node “synced” with that on another node?
Here's my understanding of the execution flow of blockchain:
Consider two nodes, node1 and node2. Let's say there are 10 users on node1. They're making transactions, but none of these are actually ...
0
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1answer
121 views
How to get erc20 contract deploy time / block number
I am building a framework for ERC20 tokens.
Aim is to scan all events (Transfer and Approve) generated by ERC20 contract, for which I am using web3.js getPastEvents.
I have set the toBlock to web3....
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0answers
703 views
Ethereum Blockchain Size calculation from Etherscan
I was looking into Etherscan.io charts of Ethereum Block Count and Ethereum Average Block Size. Both of them have the data since 07/30/2015 and if one multiply both time-series
(Ex. 07/30/2015 - 644 ...
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1answer
29 views
Couldn't reach block gas limit
When i try to send a lot of transaction, every block looks like only use half of its gas limit.
How can i make block to use all its gas limit until it can't handle more transaction?
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1answer
48 views
Can I set the block size in genesis block by puppeth?
Found the block size is set to 30K in genesis block. How can I modify this value to 100K or 1M by puppeth?
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1answer
21 views
I have done simple data transaction on ropsten, it's stll increasing blocks confirmation
Why there are so many block confirmations in small transaction?
How blocks are working while transaction?
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2answers
52 views
All my blocks has deleted
I have a private network for testing. My problem is when ever I stop running geth network, all of my mined blocks are gone. I run like
geth --datadir "ethereum/node1" --port 30301 --networkid 1234 --...
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0answers
42 views
how to check if a block has a transaction to an address only by using the block header
Question is self explanatory. How can I check if a block has a transaction to or from an address only by using the block header?
Question is prompted by this comment - How to explore all ...
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1answer
98 views
Transaction receiving ether from a contract address
Are transactions sending ether from contract addresses to normal addresses listed in block.transactions or are they not trivial to detect?
If not in block.transactions than how to detect?
0
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1answer
27 views
What is saved on every block on Ethereum?
In Bitcoin every block has the information about the transaction (A sends money to B, C to D etc). And everytime a new transaction (someone sends money to another address) is sent, the miners will ...
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0answers
76 views
Showing block confirmations on a user transaction, best practices?
I'm working on a site that allows users to deploy smart contracts via MetaMask. Basically they customize it, it gets compiled, and then the user deploys it by via a MetaMask transaction.
I would like ...
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1answer
68 views
Examples of light-client interactions to extract Merkle proofs?
I'd be grateful for pointers to working examples of interacting with the geth/parity light-client protocols. I'm particularly interested in working code which shows how to extract the Merkle proof ...
0
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1answer
29 views
Uploading big contract to the Ethereum blockchain
As far as I understand, there is a limit on the block size. But what if I want to upload a large contract that exceeds the blocksize? Will it not be allowed?
