Mastering Ethereum
前回(visionと第1〜2章)
3章 イーサリアムクライアント
- イーサリアムネットワーク
- クライアント特性
- クライアント実行
イーサリアムベースのネットワーク
- イーサリアム
- イーサリアムクラシック
- Ella
- Expanse
- Ubiq
- Musicoin
- ...
プロトコルレベルでは互換性を持っている一方、クライアントレベルではメンテナンスがそれぞれ必要。
イーサリアムクライアントソフトウェアの各バージョンが、全てのイーサリアムベースのブロックチェーンを実行するわけではない。
今回イーサリアムプロトコルを取り上げる。
そして現在の主要なクライアント実装は、異なる言語で実装された６つのイーサリアムクライアント実装。
主要な６つのイーサリアムプロトコル
- Parity(Rust実装)
- Geth(Go言語実装) ※go-ethereum
- cpp-ethereum(C++実装)
- pyethereum(Python実装)
- Mantis(Scala実装)
- Harmony(Java実装)
クライアントを利用してノードを立ち上げる方法を学ぶ。
今回代表的なクライアントであるGethを利用。
CLIとAPIの紹介は時間あればですが、今回はほんの触りの概要まで。
full node or Not full
light client
ライトクライアント(ビットコインのSPVクライアントと類似)は、
・トランザクションの検証にブロックヘッダーをフルノードから取得して検証
・マークルプルーフを用いてブロックチェーンにトランザクションが含まれているかを検証
※いずれも検証しないものはリモートクライアントとして区別(mobile, ブラウザ(metamask,Jaxx, mew, mycrypt, mist)
full node
フルノードは、
・イーサリアムブロックチェーンの完全なコピーを保存
・保持する全てのトランザクションについて検証可能
cost
フルノード維持には、
・HWリソース
・帯域幅の広いNW
が必要でそれなりに費用がかかる。
(例)フルノードは200GBのデータをダウンロードしてlocal storage(HDD/SDD)に保存する。そして随時トランザクションやブロックデータは増えていく等。
spec
最低要件(mainnetの場合)
高速cpu : 2 core以上
空き容量：200GB以上
RAM: SSD 4GB/HDD 8GB以上
NW回線: 下りが8Mbps
推奨要件(mainnetの場合)
高速cpu : 4 core以上
高速SSD: 500GB以上の空き容量
RAM: 16GB以上
NW回線: 下りが25Mbps以上
full node
長所
・全てのトランザクションに対して信頼性の高い検証が可能
・仲介者なしでpublic chain上のcontractとやりとり可能
・仲介者なしでcontractをpublic chainにデプロイ可能、public chain上のcontractと直接やりとり
・public chain上の状態を読んでいるという情報を第三者に知られることなくchain上の状態を問い合わせ可能
・chainの状態をオフラインで問い合わせ可能(読み取り専用)
・ネットワークへの貢献(レジリエンスと検閲耐性)
短所
・
full node
・HWリソースとNW帯域確保のcost
・初回起動時から完全な同期までに数日かかるなど時間を要す
・メンテナンス・アップグレードするには、常時オンライン接続をしておく必要がある。
public(testnet)
・データの同期量が10GB等比較的少なくて済む。完全な同期も数時間ほど。
・テスト用イーサが無償で取得できる
・多数のuserやcontractが存在するpublic chainであり、実環境に近い。
反面、実際のETHやpublic chain上での全ての機能はtestで使えない(gasがfreeなど)
local chain
・同期の必要がなく自分でmining
・他userなどなく自分だけで利用できる。contractも同様
・テスト用ETHは必要なく、mining報酬を自分に渡してそれをtestに使う。
production
本番プロダクションではメインネット(mainnet)上で実際に動作するノードを用いる(主に特性に応じてフルノードなど)。
develop
テストネット(testnet: 小規模なパブリックブロックチェーンに接続するノード)、local private chain(Ganache etc...)やクラウドベースのイーサリアムクライアントを利用して通常の開発を行うことができる。
Go-Ethreum
https://github.com/ethereum/go-ethereum
> git clone https://github.com/ethereum/go-ethereum.git
実機demo&ワークショップ
➜ ~ geth -help
NAME:
geth - the go-ethereum command line interface
Copyright 2013-2019 The go-ethereum Authors
USAGE:
geth [options] command [command options] [arguments...]
VERSION:
1.9.8-stable
COMMANDS:
account Manage accounts
attach Start an interactive JavaScript environment (connect to node)
console Start an interactive JavaScript environment
copydb Create a local chain from a target chaindata folder
dump Dump a specific block from storage
dumpconfig Show configuration values
export Export blockchain into file
export-preimages Export the preimage database into an RLP stream
import Import a blockchain file
import-preimages Import the preimage database from an RLP stream
init Bootstrap and initialize a new genesis block
inspect Inspect the storage size for each type of data in the database
js Execute the specified JavaScript files
license Display license information
makecache Generate ethash verification cache (for testing)
makedag Generate ethash mining DAG (for testing)
removedb Remove blockchain and state databases
retesteth Launches geth in retesteth mode
version Print version numbers
wallet Manage Ethereum presale wallets
help, h Shows a list of commands or help for one command
ETHEREUM OPTIONS:
--config value TOML configuration file
--datadir value Data directory for the databases and keystore (default: "/Users/akira.tamai/Library/Ethereum")
--datadir.ancient value Data directory for ancient chain segments (default = inside chaindata)
--keystore value Directory for the keystore (default = inside the datadir)
--nousb Disables monitoring for and managing USB hardware wallets
--pcscdpath value Path to the smartcard daemon (pcscd) socket file
--networkid value Network identifier (integer, 1=Frontier, 2=Morden (disused), 3=Ropsten, 4=Rinkeby) (default: 1)
--testnet Ropsten network: pre-configured proof-of-work test network
--rinkeby Rinkeby network: pre-configured proof-of-authority test network
--goerli Görli network: pre-configured proof-of-authority test network
--syncmode value Blockchain sync mode ("fast", "full", or "light") (default: fast)
--exitwhensynced Exits after block synchronisation completes
--gcmode value Blockchain garbage collection mode ("full", "archive") (default: "full")
--ethstats value Reporting URL of a ethstats service (nodename:secret@host:port)
--identity value Custom node name
--lightkdf Reduce key-derivation RAM & CPU usage at some expense of KDF strength
--whitelist value Comma separated block number-to-hash mappings to enforce (<number>=<hash>)
LIGHT CLIENT OPTIONS:
--light.serve value Maximum percentage of time allowed for serving LES requests (multi-threaded processing allows values over 100) (default: 0)
--light.ingress value Incoming bandwidth limit for serving light clients (kilobytes/sec, 0 = unlimited) (default: 0)
--light.egress value Outgoing bandwidth limit for serving light clients (kilobytes/sec, 0 = unlimited) (default: 0)
--light.maxpeers value Maximum number of light clients to serve, or light servers to attach to (default: 100)
--ulc.servers value List of trusted ultra-light servers
--ulc.fraction value Minimum % of trusted ultra-light servers required to announce a new head (default: 75)
--ulc.onlyannounce Ultra light server sends announcements only
DEVELOPER CHAIN OPTIONS:
--dev Ephemeral proof-of-authority network with a pre-funded developer account, mining enabled
--dev.period value Block period to use in developer mode (0 = mine only if transaction pending) (default: 0)
ETHASH OPTIONS:
--ethash.cachedir value Directory to store the ethash verification caches (default = inside the datadir)
--ethash.cachesinmem value Number of recent ethash caches to keep in memory (16MB each) (default: 2)
--ethash.cachesondisk value Number of recent ethash caches to keep on disk (16MB each) (default: 3)
--ethash.dagdir value Directory to store the ethash mining DAGs (default: "/Users/akira.tamai/Library/Ethash")
--ethash.dagsinmem value Number of recent ethash mining DAGs to keep in memory (1+GB each) (default: 1)
--ethash.dagsondisk value Number of recent ethash mining DAGs to keep on disk (1+GB each) (default: 2)
TRANSACTION POOL OPTIONS:
--txpool.locals value Comma separated accounts to treat as locals (no flush, priority inclusion)
--txpool.nolocals Disables price exemptions for locally submitted transactions
--txpool.journal value Disk journal for local transaction to survive node restarts (default: "transactions.rlp")
--txpool.rejournal value Time interval to regenerate the local transaction journal (default: 1h0m0s)
--txpool.pricelimit value Minimum gas price limit to enforce for acceptance into the pool (default: 1)
--txpool.pricebump value Price bump percentage to replace an already existing transaction (default: 10)
--txpool.accountslots value Minimum number of executable transaction slots guaranteed per account (default: 16)
--txpool.globalslots value Maximum number of executable transaction slots for all accounts (default: 4096)
--txpool.accountqueue value Maximum number of non-executable transaction slots permitted per account (default: 64)
--txpool.globalqueue value Maximum number of non-executable transaction slots for all accounts (default: 1024)
--txpool.lifetime value Maximum amount of time non-executable transaction are queued (default: 3h0m0s)
PERFORMANCE TUNING OPTIONS:
--cache value Megabytes of memory allocated to internal caching (default = 4096 mainnet full node, 128 light mode) (default: 1024)
--cache.database value Percentage of cache memory allowance to use for database io (default: 50)
--cache.trie value Percentage of cache memory allowance to use for trie caching (default = 25% full mode, 50% archive mode) (default: 25)
--cache.gc value Percentage of cache memory allowance to use for trie pruning (default = 25% full mode, 0% archive mode) (default: 25)
--cache.noprefetch Disable heuristic state prefetch during block import (less CPU and disk IO, more time waiting for data)
ACCOUNT OPTIONS:
--unlock value Comma separated list of accounts to unlock
--password value Password file to use for non-interactive password input
--signer value External signer (url or path to ipc file)
--allow-insecure-unlock Allow insecure account unlocking when account-related RPCs are exposed by http
API AND CONSOLE OPTIONS:
--ipcdisable Disable the IPC-RPC server
--ipcpath value Filename for IPC socket/pipe within the datadir (explicit paths escape it)
--rpc Enable the HTTP-RPC server
--rpcaddr value HTTP-RPC server listening interface (default: "localhost")
--rpcport value HTTP-RPC server listening port (default: 8545)
--rpcapi value API's offered over the HTTP-RPC interface
--rpc.gascap value Sets a cap on gas that can be used in eth_call/estimateGas (default: 0)
--rpccorsdomain value Comma separated list of domains from which to accept cross origin requests (browser enforced)
--rpcvhosts value Comma separated list of virtual hostnames from which to accept requests (server enforced). Accepts '*' wildcard. (default: "localhost")
--ws Enable the WS-RPC server
--wsaddr value WS-RPC server listening interface (default: "localhost")
--wsport value WS-RPC server listening port (default: 8546)
--wsapi value API's offered over the WS-RPC interface
--wsorigins value Origins from which to accept websockets requests
--graphql Enable the GraphQL server
--graphql.addr value GraphQL server listening interface (default: "localhost")
--graphql.port value GraphQL server listening port (default: 8547)
--graphql.corsdomain value Comma separated list of domains from which to accept cross origin requests (browser enforced)
--graphql.vhosts value Comma separated list of virtual hostnames from which to accept requests (server enforced). Accepts '*' wildcard. (default: "localhost")
--jspath loadScript JavaScript root path for loadScript (default: ".")
--exec value Execute JavaScript statement
--preload value Comma separated list of JavaScript files to preload into the console
NETWORKING OPTIONS:
--bootnodes value Comma separated enode URLs for P2P discovery bootstrap (set v4+v5 instead for light servers)
--bootnodesv4 value Comma separated enode URLs for P2P v4 discovery bootstrap (light server, full nodes)
--bootnodesv5 value Comma separated enode URLs for P2P v5 discovery bootstrap (light server, light nodes)
--port value Network listening port (default: 30303)
--maxpeers value Maximum number of network peers (network disabled if set to 0) (default: 50)
--maxpendpeers value Maximum number of pending connection attempts (defaults used if set to 0) (default: 0)
--nat value NAT port mapping mechanism (any|none|upnp|pmp|extip:<IP>) (default: "any")
--nodiscover Disables the peer discovery mechanism (manual peer addition)
--v5disc Enables the experimental RLPx V5 (Topic Discovery) mechanism
--netrestrict value Restricts network communication to the given IP networks (CIDR masks)
--nodekey value P2P node key file
--nodekeyhex value P2P node key as hex (for testing)
MINER OPTIONS:
--mine Enable mining
--miner.threads value Number of CPU threads to use for mining (default: 0)
--miner.notify value Comma separated HTTP URL list to notify of new work packages
--miner.gasprice value Minimum gas price for mining a transaction (default: 1000000000)
--miner.gastarget value Target gas floor for mined blocks (default: 8000000)
--miner.gaslimit value Target gas ceiling for mined blocks (default: 8000000)
--miner.etherbase value Public address for block mining rewards (default = first account) (default: "0")
--miner.extradata value Block extra data set by the miner (default = client version)
--miner.recommit value Time interval to recreate the block being mined (default: 3s)
--miner.noverify Disable remote sealing verification
GAS PRICE ORACLE OPTIONS:
--gpoblocks value Number of recent blocks to check for gas prices (default: 20)
--gpopercentile value Suggested gas price is the given percentile of a set of recent transaction gas prices (default: 60)
VIRTUAL MACHINE OPTIONS:
--vmdebug Record information useful for VM and contract debugging
--vm.evm value External EVM configuration (default = built-in interpreter)
--vm.ewasm value External ewasm configuration (default = built-in interpreter)
LOGGING AND DEBUGGING OPTIONS:
--fakepow Disables proof-of-work verification
--nocompaction Disables db compaction after import
--verbosity value Logging verbosity: 0=silent, 1=error, 2=warn, 3=info, 4=debug, 5=detail (default: 3)
--vmodule value Per-module verbosity: comma-separated list of <pattern>=<level> (e.g. eth/*=5,p2p=4)
--backtrace value Request a stack trace at a specific logging statement (e.g. "block.go:271")
--debug Prepends log messages with call-site location (file and line number)
--pprof Enable the pprof HTTP server
--pprofaddr value pprof HTTP server listening interface (default: "127.0.0.1")
--pprofport value pprof HTTP server listening port (default: 6060)
--memprofilerate value Turn on memory profiling with the given rate (default: 524288)
--blockprofilerate value Turn on block profiling with the given rate (default: 0)
--cpuprofile value Write CPU profile to the given file
--trace value Write execution trace to the given file
METRICS AND STATS OPTIONS:
--metrics Enable metrics collection and reporting
--metrics.expensive Enable expensive metrics collection and reporting
--metrics.influxdb Enable metrics export/push to an external InfluxDB database
--metrics.influxdb.endpoint value InfluxDB API endpoint to report metrics to (default: "http://localhost:8086")
--metrics.influxdb.database value InfluxDB database name to push reported metrics to (default: "geth")
--metrics.influxdb.username value Username to authorize access to the database (default: "test")
--metrics.influxdb.password value Password to authorize access to the database (default: "test")
--metrics.influxdb.tags value Comma-separated InfluxDB tags (key/values) attached to all measurements (default: "host=localhost")
WHISPER (EXPERIMENTAL) OPTIONS:
--shh Enable Whisper
--shh.maxmessagesize value Max message size accepted (default: 1048576)
--shh.pow value Minimum POW accepted (default: 0.2)
--shh.restrict-light Restrict connection between two whisper light clients
DEPRECATED OPTIONS:
--lightserv value Maximum percentage of time allowed for serving LES requests (deprecated, use --light.serve) (default: 0)
--lightpeers value Maximum number of light clients to serve, or light servers to attach to (deprecated, use --light.maxpeers) (default: 100)
--minerthreads value Number of CPU threads to use for mining (deprecated, use --miner.threads) (default: 0)
--targetgaslimit value Target gas floor for mined blocks (deprecated, use --miner.gastarget) (default: 8000000)
--gasprice value Minimum gas price for mining a transaction (deprecated, use --miner.gasprice) (default: 1000000000)
--etherbase value Public address for block mining rewards (default = first account, deprecated, use --miner.etherbase) (default: "0")
--extradata value Block extra data set by the miner (default = client version, deprecated, use --miner.extradata)
MISC OPTIONS:
--override.istanbul value Manually specify Istanbul fork-block, overriding the bundled setting (default: 0)
--help, -h show help
COPYRIGHT:
Copyright 2013-2019 The go-ethereum Authors