Questions tagged [blockchain]

The Ethereum blockchain is a distributed database based on the Ethereum whitepaper specification and stores both the full transaction list and the most recent state.

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7
votes
1answer
699 views

Block header structure change under Proof of Stake?

The yellow paper describes the below block header structure: This includes difficulty, beneficiary, mixHash and nonce values. Presumably these will be redundant under Proof-of-Stake. How will the ...
5
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1answer
835 views

Call write function, which doesn't change contract value

I'm new in smart contracts and faced with one problem. After deploying contract to my test local blockchain network, i try to set new value via setter, after that I call get method of contract and it ...
4
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0answers
353 views

What is the current size of the Ethereum State?

What is the current size of Ethereum's state in bytes? I am not asking about the size of the blockchain with blocks headers, transactions and receipts. I am looking for the size of all the structure ...
4
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1answer
427 views

Storing private data off-chain with a sharing feature upon request

My question is not very technical from an implementation point of view, but I am looking for advice to achieve a specific use case using blockchain tech. I would greatly appreciate any insights or ...
4
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1answer
338 views

Why does geth -light start importing block headers from 3297471

I've been using geth to download the blockchain (on full) and one of the requirements for my research involves the use of light clients. I used 2 computers to download the blockchain on the -light ...
4
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0answers
130 views

Did the ripemd precompiled contract get deleted?

A bug "caused account 0000000000000000000000000000000000000003 to be deleted in block 2675119, even though the deletion should have been reverted due to an out of gas error." Source Did account 0..3 ...
4
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0answers
132 views

Genesis.json permanence and updating the blockchain

I understand that the initial genesis.json attributes are a permanent thing, and it cannot be changed retroactively. But what I want to know is which parameters are changeable afterwards and how? ...
4
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1answer
146 views

Can someone share your geth export file with me?

I need to setup an archival node ASAP but the download takes around 1-2 block per second. With this speed it will finish in 2 months (if it doesn't stall, but it does, I have to restart it manually ...
3
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1answer
62 views

Blockchain Performance Metrics

How can I measure blockchain execution time, latency and throughput? Which API do I use to measure? Anyone suggest any article or book for me to read about the blockchain performance metrics?
3
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1answer
73 views

How to download the blockchain of a single ethereum contract’s address?

The blockchain required to run ethereum is several Terabytes large. This means more than 9 years would be required to download it with my connection speed. In my case, I just want to know if the ...
3
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0answers
82 views

Zero Knowledge Range Proofs

I am new to the world of Zero Knowledge Range Proofs. I read the following on GitHub: https://github.com/ing-bank/zkproofs The Zero Knowledge Range Proof allows the blockchain network to validate ...
3
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0answers
192 views

What filesystem should I use for geth and leveldb?

I used old LGA775 machine for running geth node. Its mobo has older sata 3gb/s (benchmark showed that ssd bottlenecked there) and only 4gb of DDR2, with windows installed. So syncing is a real pain ...
3
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1answer
69 views

Understanding what happens between transaction creation and block creation in Proof of Authority

I am currently writing my thesis where I'm investigating the potential of blockchain technology to become the underlying technology in a system that is create and record qualifications. I'm at the ...
3
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0answers
203 views

How to access txpool pending transactions using Netherum?

I want to get list of transactions which are in pending state & queued state in txpool. I can see these transactions in pool using txpool.inspect command. I tried code given in nethereum sample ...
3
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0answers
1k views

Mining hangs on Generating DAG in progress

I am trying to initialize rpc using the below command and start miner using miner.start(1); geth --rpcapi eth,web3,personal --rpc --networkid=15 Mining starts successfully with below logs but it ...
3
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0answers
110 views

Parity create testing transactions and blocks

For test purposes, I would like to make test blocks including test transactions against main net. For example I would like to make a transaction that sends one ether from 0x1234567... to 0x99999999......
3
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1answer
227 views

Uncle blocks in Parity PoA blockchain

As I know that there is no competition for mining new blocks in POA blockchain as each node mines new block at its given time slot. I have a parity PoA blockchain setup with 5 nodes. While examining ...
3
votes
1answer
679 views

geth - admin,addPeer() and static-nodes.json don't work

I'm trying to connect two nodes (both miners) on my private network. They are based on the same VM in different data directories. They have different ports and are based on the same genesis file and ...
3
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0answers
323 views

SSL Support for Communication Between Geth Nodes

We are using private Ethereum network for a multi entity use-case. The problem is that all these entities geth nodes sits behind a firewall which only allows TLS traffic. The node that's broadcasting ...
3
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0answers
1k views

How to encode data payload in ETH transaction

I'm using python to sign and send ETH transactions, and would like to do the same for ERC-20 token transactions as well. I'm having trouble correctly encoding the data payload to invoke the transfer ...
3
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0answers
446 views

How can i confirm transaction in geth from other peer of blockchain?

I have a query , I have create a private blockchain in which one geth node1 is use for transaction taking and other one(node2) is for mining .They are peered with each other and perfectly ...
3
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0answers
146 views

Geth bus fatal error

My geth node (v1.4.18 on testnet) has unexpectedly go down throwing an error like this: I1028 04:46:29.305710 ethash.go:259] Generating DAG for epoch 44 (size 1442839168) (...
3
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0answers
189 views

Blockchain compression Suggestions

I am planning to do a course project on block chain compression so that network transfer time is optimized. I read somewhere that the EVM bytecode component of the blockchain can be compressed. Is ...
3
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0answers
140 views

Updated geth, now I am re-syncing the whole blockchain

This is the first time I have updated geth. I was at a build of geth from several weeks ago, and this morning I updated to 1.4.12. I downloaded the pre-built binary to a new location on disk, ...
2
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1answer
30 views

What is meant by on-chain randomness? What is the difference between on-chain and off-chain operations in the context of randomness?

I want to understand on-chain and off-chain operations in the context of randomness. Kindly provide me an example so that its clear to me. I got one post here: What are offchain and onchain ...
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0answers
27 views

Why does Ethereum use JSON-RPC and not gRPC?

I am fairly new to networking protocols especially JSON-RPC and gRPC as they are not nearly as common in web development as REST. I was reading around and seems like gRPC generally performs better. So ...
2
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0answers
36 views

Confidential data encryption on blockchain

I already built a supply chain that is able to collect product information on Ethereum. Now, that data can be confidential, but I still want to do Matrix calculations on it. I came across homomorphic ...
2
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0answers
28 views

How can I test a consensus protocol that I created?

Currently, I am designing my own blockchain consensus protocol and I want to test its performance. Is there any available tool or well-known framework that gives me this ability?
2
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1answer
51 views

Blockchain overhead - general question

I was reviewing the blockchain technology the other day, Maybe this is not the right place or maybe I should rephrase my question but.. Blockchain is peer to peer, every peer stores the data Data is ...
2
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2answers
248 views

error in remix IDE

I am facing this type of Error in 'remix IDE' while connecting it to 'web3.js@0.20.2' Error: Failed to decode output: Error: insufficient data for uint256 type (arg="", coderType="uint256", value="...
2
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1answer
74 views

Are the timestamps of blocks for Ethereum only accepted when they are monotonically increasing?

Are the timestamps of blocks for Ethereum only accepted when they are monotonically increasing? If yes, why? And why other blockchains like Bitcoin and other blockchains with shorter block time can ...
2
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2answers
35 views

How can I find the block where a user enacted a certain event on a contract?

I'm trying to build a web3.py program to take in a given user's address, and return the amount of ETH traded since they added liquidity to a Uniswap exchange. Uniswap is a smart contract on the ...
2
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1answer
27 views

Etherescan Unique Address Growth Chart - How is it computed?

how does Etherscan get this information from the blockchain? Is it possible via using a web3 module? Any insight? https://etherscan.io/chart/address
2
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0answers
15 views

I am sending some ether from account[0] to account[1] using geth console. But the amount is not getting added to the receiving account

I tried to mine the transaction using miner.start() command, still account balance remains the same > miner.start(8) I0428 16:27:15.927553 miner/miner.go:136] Starting mining operation (CPU=8 TOT=...
2
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2answers
504 views

ganache-cli: how to persist new created accounts

I start my service by: ganache-cli -d --gasPrice 0 -q --db=./db This persists my 10 defaults created accounts, but when I create new accounts using Web3: web3.eth.personal.newAccount('password') ...
2
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0answers
57 views

Automatic sign of Transaction

Is there any secure solution(without exposing a Private key of the user) to automatically sign transactions, which are requested from a DApp, so that user doesn't have to sign each of them manually? I ...
2
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0answers
631 views

How Merkle trees are implemented in a database exactly

I have just checked out these resources: What is a Merkle Tree? Beginner’s Guide to this Blockchain Component Using Merkle trees to detect inconsistencies in data Exploring the use of Hash Trees for ...
2
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1answer
100 views

How can I execute transferFrom function in node js

There is solidity erc865 code function transferFromPreSigned( bytes _signature, address _from, address _to, uint256 _value, uint256 _fee, uint256 _nonce ) public ...
2
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0answers
151 views

Gas estimation failed

whenever I want to run this code I get this error "Gas estimation errored with the following message (see below). The transaction execution will likely fail. Do you want to force sending? VM ...
2
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0answers
55 views

Transactions are not mining for accounts created by Nethereum.Accounts.Account method but works for accounts created by web3.Personal.NewAccount

Transactions are not mining & in pending state for long time, for transactions with accounts created using Nethereum.Accounts.Account(privateKey). But mining works for accounts created using web3....
2
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0answers
782 views

Total number of state entries

I am syncing my ethereum blockchain using the default syncmode. I want to know how many total state entries are there because currently the highest block is 6544578 and the number of pulled states i.e....
2
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0answers
145 views

Monitoring Eth Transactions and Syncing Native Database transactions with Etherium Blockchain

Currently, I have a node.js application which interacts with geth through web sockets. I have a listener, web3.eth.subscribe( 'pendingTransactions', function(err, result) { if(!err) { ...
2
votes
1answer
92 views

In what way does Sharding allocate transactions for each shard? state? or node selection?

In what way does Sharding allocate transactions for each shard? I know that accounts are assigned to each shard based on prefix in the account's address and each shard processes the transactions ...
2
votes
1answer
73 views

How to increase stored block states from 128 to 10 000 in Geth?

AFAIK Geth preserves states for the last 128 blocks by default. I would like to keep states for, say 10000 blocks (not turning myself into archive node). Is it possible?
2
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3answers
291 views

Does Using Infura Breaks Decentralization?

Decentralized applications have a philosophy: they are immutable,secure and trustless applications. You can connect to Blockchain and be sure about that features. Infura is a great tool when ...
2
votes
1answer
43 views

Are there any forks or alternate flavors of Ethereum that allow cross-chain swaps between two EVM-like chains?

I’d like to run an alternative consensus protocol based on the geth client. Since geth already has a ton of consensus protocols, I was wondering if any coins on the market were able to do the ...
2
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0answers
45 views

can raiden network be used on ethereum PoA(proof of Authority)?

https://github.com/raiden-network/raiden can raiden network be used on ethereum PoA(proof of Authority) ? If it can , how to use it? Please help.
2
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1answer
409 views

How to change block generation period?in POA private ethereum blockchain

my genesis.json like that: "config": { "chainId": 333, "homesteadBlock": 1, "eip150Block": 2, "eip150Hash": "0x0000000000000000000000000000000000000000000000000000000000000000", "...
2
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0answers
149 views

Who created this alt-Ropsten blockchain and why?

I usually test on Rinkeby, but this week I have to test some mining stuff, so I tried to get synced up with Ropsten. Unfortunately, after 3 days of trying, I still haven't had any success. The main ...
2
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0answers
156 views

Can not access quorum's contract from webpage *CORS*

I am getting following error on browser's console while accessing contracts. Failed to load http://localhost:22000/: Response to preflight request doesn't pass access control check: No 'Access-...

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