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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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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 ...
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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 ...
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120 views

Syncing a fraction of the blockchain

I have a few questions about the way the blockchain syncs. I noticed on a couple of posts while researching that it's possible to start the block chain from a certain block. It was suggested that if ...
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129 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? ...
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45 views

Who hosts IPFS?

I'm trying to get my head wrapped around how IPFS actually stores files. There is no IPFS coin, so who is hosting these files and are they getting paid to host them?
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74 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 ...
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57 views

Retrieve CHAIN_ID of the executing chain from a Solidity contract

Is there a way to directly be able to retrieve CHAIN_ID information about the executing chain from a smart contract? I know that for any chain that has EIP-155 implemented, CHAIN_IDs are retrievable ...
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87 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......
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280 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 ...
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250 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 ...
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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 ...
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473 views

Syncing block chain

I was syncing the blockchain using something like geth --fast --cache=2000 -jitvm. It reached about block #3819000, and then it did something odd. It stopped saying "Imported x reciepts" or "...
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663 views

block download canceled, geth 1.5.9 would not download blocks

when starting out geth I cant download past block 1292880 does anyone have any idea why it would not download any more blocks?
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109 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) (...
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181 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 ...
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138 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, ...
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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 ...
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25 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 ...
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65 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 ...
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25 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....
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686 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 ...
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37 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.
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116 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 ...
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125 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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538 views

Hyperledger Fabric and Ethereum Blockchain Integration

How can I connect Hyperledger Fabric to the ethereum blockchain so as to make payments. I am recording the number of tokens to be alloted in the hyperledger system I want to access the data and then ...
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115 views

Ethereumjs: How to save the blockchain / state

Ethereumjs noob here. Using the code below, I'm able to create a new blockchain and add blocks to it. But the blocks are not being saved to the database. var blockdb = levelup("./blockdb", {...
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Importing wallet into Mist using custom datadir

I'm having an issue that seems to be quite common but I haven't found a solution. I'm using Ethereum Wallet 0.9 and I have all the application data, including the blockchain on an external drive. When ...
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131 views

Read function returning blank array in geth

I have deployed a smart contract on geth which has 2 simple read, write functions in it. Then I called the write function; e.g. payment.place_order("Laptop", 10,{from:eth.accounts[0]}). After the ...
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466 views

Geth always returning a 0 balance?

i´m mining now for about 3 days with 3 rigs each with over 50Mh/s, but my balance is still 0. Does anybody know why ?
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150 views

Deploy Button is not responding

I am newbie to solidity, this is my first PoC on testnet, i am just trying to understand how things works. i am following the main tutorial on Ethereum website, under this URL https://www.ethereum....
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300 views

How exactly does a unique asset get tokenized?

Say I have a set of assets, each with their own serial# or unique Id. How exactly would I create tokens linked to each asset that could be traded on a 1 to many basis? (ie: trade this one special ...
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198 views

What is the blockchain download size and can i reduce it in some way?

I am currently on a connection with a download cap, and was wondering what the current download size for the whole blockchain was, and if i could reduce this download size to under 2 GB? I'm ...
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162 views

In a private blockchain network, can we delete the first N blocks and reassign the N+1th block as the genesis block?

I am aware of the data loss caused by deleting the first N blocks. But I am curious to know whether such a task is possible or not. If so, how to practically implement it? ( I am using go-ethereum. ...
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1k views

How to get raw binary data from ethereum blockchain?

I want to get ethereum blocks as binary data and parse them manually to get raw ethereum transactions. Are there any good manuals how to do it? UPDATE: how ethereum genesis block (at height #0) looks ...
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253 views

Synchronisation issue on Mainnet, testnet and private network

I am just unable to synchronise on any kind of network either main network , testnet and not even on private network. I have updated my geth instance to a newer version - Geth/v1.5.9-stable-a07539fb/...
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79 views

Ethereum send transactions are unsuccessful when I run the node and miner in same machine

I have started the Ethereum client using the Go Ethereum. And also started the Ethereum miner on the same machine. Now node and miner are running in the single windows function. If I try to send ...
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176 views

Public-of-chain using proof-of-authority, where authority is defined as the amount of work on your public key

I'm wondering if there would be benefits to create a public blockchain based on the same algorithms used for private, proof-of-authority blockchain, except replacing the concept of authority by the ...
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485 views

In parity, how can I delete the last blocks I downloaded without corrupting the database?

I have found the blockchain data in parity. I go to overlayrecent folder and from there to the db folder. It looks like the blocks are the .sst files. How can I delete the last blocks I downloaded ...
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235 views

Connection between two blockchains

I am looking for an approach to creating a connection between two blockchain-networks. I found out that I can use oracles to get data from extern systems (= second blockchain-network). But how can I ...
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267 views

geth taking a long time to mine a block

I'm using the embark framework to deploy some smart contracts to a private Ethereum network. The problem is, the network behaves differently on separate machines, even though they're similarly spec'd -...
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82 views

Mist 0.8.5 & Geth 1.5.0

Current Mist is 0.8.5 and it runs geth 1.4.17. How can I initial geth 1.5.0 by Mist 0.8.5 without manually start Geth 1.5.0 first ? It's all to do with instruct geth that chaindata is on an external ...
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57 views

Distributed application with client side stuff?

I would like to write a smart contract which allow users to publish forecasts and then vote which forecast was the best. Adding a forecast should be done manually by user. But I would like to automate ...
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870 views

Comparing Ripple and Ethereum

What advantages and disadvantages does Ripple have over Ethereum?
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87 views

Chaindata behind in blocks

My Mist wallet shows Im synced but when I go to the chaindata folder it is about 130000 behind.Does anyone know why this is. I do not seem to have a problem with geth or mist but curious why the ...
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28 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 ...
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42 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 ...
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42 views

Transaction submitted through Infura, but not from local node

So, I have a Rinkeby fast sync on my server. When I try to interact with my contract and transfer something, geth says "Submitted transaction", but then I can't find it using its hash on etherscan. ...
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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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How many Times I can Bid on Same domain name and Is There any way to increase bidding amount during auction

Is it Possible to increase my bidding during ENS auction period ?How can see highest bidding before reveling period. How many times i can bid for the same doamin in 3 days aution period
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47 views

Connection of web3 with Ropsten

How do I connect my web3 to ropsten network. I know how to pass the url of ropsten netwrok in web3 instance in my script tag but when i try to to console.log(web3.eth.defaultaccount) it gives me ...