Questions tagged [mastering-ethereum]

Content related to/ or from the book Mastering Ethereum.

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Geth node sync even if it is not connected to any other geth node

I created a private network with five nodes. I am using geth and Prysm. When I remove the execution client node(example node5) using admin.removePeer(), the execution node disconnects from the network ...
user_go's user avatar
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ethereum world state size analysis

i am currently researching on the ethereum world state and i need updatad data of space that world state takes up in the storage. the latest data that i found is https://blog.bitmex.com/bitcoin-vs-...
Sepehr Mirnasrollahi's user avatar
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Mastering Ethereum Book - Rot13Encryption.sol - Line 22 incomprehensible

What does this mean? I know that ADD evm opcode is to add the top two items in the stack together, but i can't get the following code. add(add(text,0x20), mul(i,1))
ethereumUser's user avatar
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Need to specify the amount with payable(msg.sender)?

I am working through Mastering Ethereum and have been building their first example Faucet Contract. I recognize that a lot of their syntax is out of date, and written in ^0.4.19. I've been writing it ...
jud21's user avatar
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How to stop Private Blockchain Synchronizing

How do I stop a private blockchain synchronizing when I am in Geth Console, can't enter a command line due to continuous synchro. geth --datadir ./datadir_node_0 console
Francois Riekert's user avatar
1 vote
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Geth(clique): Getting the total initial supply on a geth private network

Using ethers/web3 is it possible to get the total initial supply (which is predetermined on clique) so I can get a hold of the data and display it somewhere.. I know how to get the total supply of an ...
Ian Gregson's user avatar
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2 answers
773 views

First time Synchronization of eth client geth

How to sync only few blocks of ethereum mainnet on geth? I don't complete blockchain to be sync and validated in my local machine. Is there any way to sync only few hundred blocks of mainnet in my ...
Proton's user avatar
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Metamask won't display balance on Ropsten test network

Going over first chapters Mastering Ethereum book, I've obtained some ether from a faucet on Ropsten Test network, but Metamask (after 2 days and 18K confirmations) still shows the balance of 0 ETH, ...
DeLorean88's user avatar
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436 views

Run bot on same server as your own Ethereum node

I have been tinkering with running a bot on a server and it uses Web3 to talk to my solidity contracts via infura. Given the latency of a bot running in location X and the infura API being based in ...
Al.'s user avatar
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Low Peer Count For a light ethereum node

I am running a Light node via Geth in a Debian OS . i am getting 1/2 max peers and for many hours of the day with 0 peers . what is the solution ? how to get atleast one peer everytime ?
Pabitra Behera's user avatar
5 votes
2 answers
13k views

Error while buying test ether from https://faucet.metamask.io/ - Mastering Ethereum

I am using Ethereum wallet MetaMask chrome extension and I am connected to Ropsten test network. I am following the instructions from the book Mastering Ethereum: Building Smart Contracts and DApps ...
Joshua DSouza's user avatar
1 vote
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586 views

Geth mining stuck: Commit new mining work on Ubuntu instance

I have an Ubuntu instance running on aws ec2. I'm currently using Ubuntu server ec2 instance with the configuration as: 1 vCPU, 2.5 GHz, Intel Xeon Family, 1 GiB memory. I'm running my Geth on this ...
Prachi Sharma's user avatar
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1 answer
362 views

How a consensus algorithm is implemented in a private Blockchain network ( ethereum )? [closed]

How to implement a new custom consensus algorithm in a network.
CryptoScroller's user avatar
1 vote
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217 views

Dapp with Authentication System

I know this question has been already asked many times, but I haven't got any satisfiable answer and so asking here. I want to create an Authentication system dApp using reactjs. The user is having ...
Prachi Sharma's user avatar
1 vote
2 answers
267 views

"Gas estimation failed" on Ropsten with Invalid RPC JSON

I'm running into an issue going through a basic example in "Mastering Ethereum"... I have a Faucet contract (on Ropsten) per the book that looks like... pragma solidity ^0.5.1; //mastering ethereum ...
d3wannabe's user avatar
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Getting error while buying test ether from https://faucet.metamask.io/

I just tried to buy a test ether from https://faucet.metamask.io but the faucet address which is supposed to give 1 ether doesn't have enough balance. Snapshot of the faucet address And when i ...
Usman Farooq's user avatar
1 vote
2 answers
227 views

Code Example from “Mastering Ethereum: Building Smart Contracts and DApps” doesn't work

I'm reading the Ethereum book of Gavin Wood right know and the following code example gives an error message when I try to compile it with truffle: pragma solidity ^0.4.22; contract calledContract { ...
Bastin's user avatar
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1 vote
1 answer
771 views

Can I use Flutter or Android Studio to design front end instead of using react.js and still be able to interact with ethereum?

I am new to blockchain and currently learning solidity. I have understood the concept behind blockchain and solidity is also good so far. I can design mocha tests and deploy the contract on local ...
abhikedia_'s user avatar
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1 answer
42 views

Trying to figure if blockchain has finished downloading.

I am working on the text, Mastering Ethereum and working on the part where one has to download the blockchain. Now I elected to use geth because parity seemed to be getting stuck on blocks for almost ...
Niana 's user avatar
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2 votes
1 answer
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How do ethereum validate a OLD transaction(say 10k blocks ago) without sync/replay-ing the full node?

When a full node receives a freshly mined new block, it seems straightfoward how we could validate all the transactions contained in the block. As we already the current world state, we could just ...
noooooooob's user avatar
1 vote
1 answer
425 views

What happens to a transaction after you clicked 'send' in Ethereum network?[Transaction life cycle at the EVM and P2P networking level]?

Ref: What happens when you type in an URL in the browser So in a web browser, it's kinda easy to reason the life cycle of an HTTP request, how it moves down the network stack, reach the server, get ...
noooooooob's user avatar
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1 answer
195 views

Why does ethereum use only GPU for computation? Why mobile processing powers are not used?

I want to make a project based on mobile (mining) using its computing power (as done by electronium). But i am unable to find any framework or platform for that. Please help me out if anyone has a ...
Rahul Mishra's user avatar
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1 answer
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Dynamic Arrays of type memory

Are the dynamic arrays of type memory fixed sized. I have read that the arrays of type memory are fixed sixed. Thanks
Sheikh's user avatar
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1 answer
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Is there a 'geth attach' man page? [duplicate]

Is there somewhere I can find what commands can be used within geth attach, and some examples of scripts as well?
Harry McGovern's user avatar
12 votes
1 answer
9k views

Defining constructors as functions with the same name as the contract is deprecated. Use "constructor(...) { ... }" instead [duplicate]

The warning is from running sample code from Mastering Ethereum, I get the above error and it says Use "constructor(...) { ... }" instead. function Migrations() public {
Vignesh Karthikeyan's user avatar