The word mining originates ter the setting of the gold analogy for crypto currencies. Gold or precious metals are scarce, so are digital tokens, and the only way to increase the total volume is through mining it. This is adequate to the extent that te Ethereum too, the only mode of issuance postbode launch is via the mining. Unlike thesis examples however, mining is also the way to secure the network by creating, verifying, publishing and propagating blocks ter the blockchain.
- Mining Ether = Securing the network = verify computation
So what is mining anyway?
Ethereum Frontier like all blockchain technologies uses an incentive-driven specimen of security. Overeenstemming is based on choosing the block with the highest total difficulty. Miners produce blocks which the others check for validity. Among other well-formedness criteria, a block is only valid if it contains proof of work (PoW) of a given difficulty. Note that te Ethereum 1.1, this is likely gonna be substituted by a proof of stake monster.
[The proof of work algorithm used is called Ethash (a modified version of Dagger-Hashimoto involves finding a nonce input to the algorithm so that the result is below a certain threshold depending on the difficulty. The point te PoW algorithms is that there is no better strategy to find such a nonce than enumerating the possibilities while verification of a solution is trivial and cheap. If outputs have a uniform distribution, then wij can ensure that on average the time needed to find a nonce depends on the difficulty threshold, making it possible to control the time of finding a fresh block just by manipulating difficulty.
The difficulty dynamically adjusts so that on average one block is produced by the entire network every 12 seconds (ie., 12 s block time). This heartbeat basically punctuates the synchronisation of system state and ensures that maintaining a fork (to permit dual spend) or rewriting history is unlikely unless the attacker possesses more than half of the network mining power (so called 51% attack).
Any knot participating ter the network can be a miner and their expected revenue from mining will be directly proportional to their (relative) mining power or hashrate, ie., number of nonces attempted vanaf 2nd normalised by the total hashrate of the network.
Ethash PoW is memory hard, making it basically ASIC resistant. This basically means that calculating the PoW requires choosing subsets of a stationary resource dependent on the nonce and block header. This resource (a few gigabyte size gegevens) is called a DAG. The DAG is totally different every 30000 blocks (a 100 hour window, called an epoch) and takes a while to generate. Since the DAG only depends on block height, it can be pregenerated but if its not, the client need to wait the end of this process to produce a block. Until clients actually precache dags ahead of time the network may practice a massive block delay on each epoch transition. Note that the DAG does not need to be generated for verifying the PoW essentially permitting for verification with both low CPU and petite memory.
Spil a special case, when you begin up your knot from scrape, mining will only embark once the DAG is built for the current epoch.
Note that mining &apos,real&apos, Ether will embark with the Frontier release. On the Olympics testnet, the Frontier pre-release, the ether mined have no value (but see Olympic prizes).
The successful PoW miner of the winning block receives:
- A static block prize for the &apos,winning&apos, block, consisting of exactly Five.0 Ether
- All of the gas expended within the block, that is, all the gas consumed by the execution of all the transactions te the block submitted by the winning miner is compensated for by the senders. The gascost incurred is credited to the miner&apos,s account spil part of the overeenstemming protocoll. Overheen time, it&apos,s expected thesis will dwarf the static block prize.
- An reserve prize for including Uncles spil part of the block, te the form of an reserve 1/32 vanaf Uncle included
Uncles are stale blocks, ie with parent that are ancestors (max 6 blocks back) of the including block. Valid uncles are rewarded ter order to neutralise the effect of network lig on the dispersion of mining prizes, thereby enlargening security. Uncles included te a block formed by the successful PoW miner receive 7/8 of the static block prize = Four.375 ether A maximum of Two uncles permitted vanaf block.
Ethash uses a DAG (directed acyclic graph) for the proof of work algorithm, this is generated for each epoch, i.e every 30000 blocks (100 hours). The DAG takes a long time to generate. If clients only generate it on request, you may see a long wait at each epoch transition before the very first block of the fresh epoch is found. However, the DAG only depends on block number, so it CAN and SHOULD be calculated te advance to avoid long wait at each epoch transition. geth implements automatic DAG generation and maintains two DAGS at a time for slick epoch transitions. Automatic DAG generation is turned on and off when mining is managed from the console. It is also turned on by default if geth is launched with the –mine option. Note that clients share a DAG resource, so if you are running numerous instances of any client, make sure automatic dag generation is switched on te at most one client.
To generate the DAG for an arbitrary epoch:
For example geth makedag 360000
/.ethash . Note that ethash uses
/.ethash (Mac/Linux) or
/AppData/Ethash (Windows) for the DAG so that it can collective inbetween clients.